annotate Lib/decimal.py @ 58925:eecf1bef052d 2.6

Merged revisions 78207 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r78207 | ezio.melotti | 2010-02-17 01:26:09 +0200 (Wed, 17 Feb 2010) | 1 line #7930: fix stripid ........
author Ezio Melotti <ezio.melotti@gmail.com>
date Tue, 16 Feb 2010 23:29:44 +0000
parents 86bf440bf9bf
children ecc32e2f4656
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1 # Copyright (c) 2004 Python Software Foundation.
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2 # All rights reserved.
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3
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4 # Written by Eric Price <eprice at tjhsst.edu>
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5 # and Facundo Batista <facundo at taniquetil.com.ar>
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6 # and Raymond Hettinger <python at rcn.com>
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7 # and Aahz <aahz at pobox.com>
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8 # and Tim Peters
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9
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10 # This module is currently Py2.3 compatible and should be kept that way
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11 # unless a major compelling advantage arises. IOW, 2.3 compatibility is
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12 # strongly preferred, but not guaranteed.
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13
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14 # Also, this module should be kept in sync with the latest updates of
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15 # the IBM specification as it evolves. Those updates will be treated
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16 # as bug fixes (deviation from the spec is a compatibility, usability
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17 # bug) and will be backported. At this point the spec is stabilizing
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18 # and the updates are becoming fewer, smaller, and less significant.
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19
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20 """
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21 This is a Py2.3 implementation of decimal floating point arithmetic based on
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22 the General Decimal Arithmetic Specification:
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23
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24 www2.hursley.ibm.com/decimal/decarith.html
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25
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26 and IEEE standard 854-1987:
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27
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28 www.cs.berkeley.edu/~ejr/projects/754/private/drafts/854-1987/dir.html
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29
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30 Decimal floating point has finite precision with arbitrarily large bounds.
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31
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32 The purpose of this module is to support arithmetic using familiar
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33 "schoolhouse" rules and to avoid some of the tricky representation
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34 issues associated with binary floating point. The package is especially
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35 useful for financial applications or for contexts where users have
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36 expectations that are at odds with binary floating point (for instance,
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37 in binary floating point, 1.00 % 0.1 gives 0.09999999999999995 instead
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38 of the expected Decimal('0.00') returned by decimal floating point).
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39
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40 Here are some examples of using the decimal module:
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41
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42 >>> from decimal import *
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43 >>> setcontext(ExtendedContext)
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44 >>> Decimal(0)
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45 Decimal('0')
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46 >>> Decimal('1')
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47 Decimal('1')
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48 >>> Decimal('-.0123')
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49 Decimal('-0.0123')
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50 >>> Decimal(123456)
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51 Decimal('123456')
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52 >>> Decimal('123.45e12345678901234567890')
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53 Decimal('1.2345E+12345678901234567892')
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54 >>> Decimal('1.33') + Decimal('1.27')
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55 Decimal('2.60')
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56 >>> Decimal('12.34') + Decimal('3.87') - Decimal('18.41')
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57 Decimal('-2.20')
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58 >>> dig = Decimal(1)
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59 >>> print dig / Decimal(3)
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60 0.333333333
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61 >>> getcontext().prec = 18
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62 >>> print dig / Decimal(3)
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63 0.333333333333333333
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64 >>> print dig.sqrt()
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65 1
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66 >>> print Decimal(3).sqrt()
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67 1.73205080756887729
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68 >>> print Decimal(3) ** 123
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69 4.85192780976896427E+58
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70 >>> inf = Decimal(1) / Decimal(0)
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71 >>> print inf
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72 Infinity
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73 >>> neginf = Decimal(-1) / Decimal(0)
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74 >>> print neginf
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75 -Infinity
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76 >>> print neginf + inf
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77 NaN
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78 >>> print neginf * inf
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79 -Infinity
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80 >>> print dig / 0
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81 Infinity
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82 >>> getcontext().traps[DivisionByZero] = 1
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83 >>> print dig / 0
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84 Traceback (most recent call last):
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85 ...
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86 ...
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87 ...
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88 DivisionByZero: x / 0
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89 >>> c = Context()
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90 >>> c.traps[InvalidOperation] = 0
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91 >>> print c.flags[InvalidOperation]
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92 0
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93 >>> c.divide(Decimal(0), Decimal(0))
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94 Decimal('NaN')
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95 >>> c.traps[InvalidOperation] = 1
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96 >>> print c.flags[InvalidOperation]
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97 1
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98 >>> c.flags[InvalidOperation] = 0
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99 >>> print c.flags[InvalidOperation]
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100 0
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101 >>> print c.divide(Decimal(0), Decimal(0))
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102 Traceback (most recent call last):
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103 ...
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104 ...
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105 ...
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106 InvalidOperation: 0 / 0
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107 >>> print c.flags[InvalidOperation]
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108 1
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109 >>> c.flags[InvalidOperation] = 0
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110 >>> c.traps[InvalidOperation] = 0
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111 >>> print c.divide(Decimal(0), Decimal(0))
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112 NaN
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113 >>> print c.flags[InvalidOperation]
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114 1
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115 >>>
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116 """
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117
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118 __all__ = [
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119 # Two major classes
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120 'Decimal', 'Context',
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121
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122 # Contexts
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123 'DefaultContext', 'BasicContext', 'ExtendedContext',
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124
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125 # Exceptions
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126 'DecimalException', 'Clamped', 'InvalidOperation', 'DivisionByZero',
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127 'Inexact', 'Rounded', 'Subnormal', 'Overflow', 'Underflow',
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128
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129 # Constants for use in setting up contexts
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130 'ROUND_DOWN', 'ROUND_HALF_UP', 'ROUND_HALF_EVEN', 'ROUND_CEILING',
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131 'ROUND_FLOOR', 'ROUND_UP', 'ROUND_HALF_DOWN', 'ROUND_05UP',
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132
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133 # Functions for manipulating contexts
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134 'setcontext', 'getcontext', 'localcontext'
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135 ]
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136
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137 import copy as _copy
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138 import numbers as _numbers
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139
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140 try:
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141 from collections import namedtuple as _namedtuple
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142 DecimalTuple = _namedtuple('DecimalTuple', 'sign digits exponent')
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143 except ImportError:
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144 DecimalTuple = lambda *args: args
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145
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146 # Rounding
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147 ROUND_DOWN = 'ROUND_DOWN'
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148 ROUND_HALF_UP = 'ROUND_HALF_UP'
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149 ROUND_HALF_EVEN = 'ROUND_HALF_EVEN'
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150 ROUND_CEILING = 'ROUND_CEILING'
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151 ROUND_FLOOR = 'ROUND_FLOOR'
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152 ROUND_UP = 'ROUND_UP'
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153 ROUND_HALF_DOWN = 'ROUND_HALF_DOWN'
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154 ROUND_05UP = 'ROUND_05UP'
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155
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156 # Errors
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157
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158 class DecimalException(ArithmeticError):
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159 """Base exception class.
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160
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161 Used exceptions derive from this.
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162 If an exception derives from another exception besides this (such as
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163 Underflow (Inexact, Rounded, Subnormal) that indicates that it is only
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164 called if the others are present. This isn't actually used for
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165 anything, though.
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166
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167 handle -- Called when context._raise_error is called and the
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168 trap_enabler is set. First argument is self, second is the
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169 context. More arguments can be given, those being after
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170 the explanation in _raise_error (For example,
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171 context._raise_error(NewError, '(-x)!', self._sign) would
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172 call NewError().handle(context, self._sign).)
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173
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174 To define a new exception, it should be sufficient to have it derive
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175 from DecimalException.
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176 """
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177 def handle(self, context, *args):
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178 pass
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179
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180
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181 class Clamped(DecimalException):
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182 """Exponent of a 0 changed to fit bounds.
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183
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184 This occurs and signals clamped if the exponent of a result has been
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185 altered in order to fit the constraints of a specific concrete
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186 representation. This may occur when the exponent of a zero result would
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187 be outside the bounds of a representation, or when a large normal
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188 number would have an encoded exponent that cannot be represented. In
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189 this latter case, the exponent is reduced to fit and the corresponding
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190 number of zero digits are appended to the coefficient ("fold-down").
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191 """
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192
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193 class InvalidOperation(DecimalException):
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194 """An invalid operation was performed.
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195
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196 Various bad things cause this:
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197
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198 Something creates a signaling NaN
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199 -INF + INF
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200 0 * (+-)INF
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201 (+-)INF / (+-)INF
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202 x % 0
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203 (+-)INF % x
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204 x._rescale( non-integer )
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205 sqrt(-x) , x > 0
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206 0 ** 0
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207 x ** (non-integer)
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208 x ** (+-)INF
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209 An operand is invalid
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210
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211 The result of the operation after these is a quiet positive NaN,
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212 except when the cause is a signaling NaN, in which case the result is
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213 also a quiet NaN, but with the original sign, and an optional
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214 diagnostic information.
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215 """
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216 def handle(self, context, *args):
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217 if args:
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218 ans = _dec_from_triple(args[0]._sign, args[0]._int, 'n', True)
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219 return ans._fix_nan(context)
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220 return _NaN
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221
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222 class ConversionSyntax(InvalidOperation):
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223 """Trying to convert badly formed string.
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224
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225 This occurs and signals invalid-operation if an string is being
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226 converted to a number and it does not conform to the numeric string
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227 syntax. The result is [0,qNaN].
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228 """
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229 def handle(self, context, *args):
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230 return _NaN
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231
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232 class DivisionByZero(DecimalException, ZeroDivisionError):
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233 """Division by 0.
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234
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235 This occurs and signals division-by-zero if division of a finite number
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236 by zero was attempted (during a divide-integer or divide operation, or a
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237 power operation with negative right-hand operand), and the dividend was
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238 not zero.
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239
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240 The result of the operation is [sign,inf], where sign is the exclusive
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241 or of the signs of the operands for divide, or is 1 for an odd power of
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242 -0, for power.
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243 """
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244
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245 def handle(self, context, sign, *args):
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246 return _SignedInfinity[sign]
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247
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248 class DivisionImpossible(InvalidOperation):
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249 """Cannot perform the division adequately.
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250
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251 This occurs and signals invalid-operation if the integer result of a
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252 divide-integer or remainder operation had too many digits (would be
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253 longer than precision). The result is [0,qNaN].
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254 """
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255
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256 def handle(self, context, *args):
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257 return _NaN
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258
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259 class DivisionUndefined(InvalidOperation, ZeroDivisionError):
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260 """Undefined result of division.
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261
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262 This occurs and signals invalid-operation if division by zero was
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263 attempted (during a divide-integer, divide, or remainder operation), and
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264 the dividend is also zero. The result is [0,qNaN].
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265 """
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266
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267 def handle(self, context, *args):
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268 return _NaN
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269
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270 class Inexact(DecimalException):
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271 """Had to round, losing information.
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272
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273 This occurs and signals inexact whenever the result of an operation is
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274 not exact (that is, it needed to be rounded and any discarded digits
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275 were non-zero), or if an overflow or underflow condition occurs. The
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276 result in all cases is unchanged.
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277
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278 The inexact signal may be tested (or trapped) to determine if a given
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279 operation (or sequence of operations) was inexact.
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280 """
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281
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282 class InvalidContext(InvalidOperation):
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283 """Invalid context. Unknown rounding, for example.
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284
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285 This occurs and signals invalid-operation if an invalid context was
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286 detected during an operation. This can occur if contexts are not checked
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287 on creation and either the precision exceeds the capability of the
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288 underlying concrete representation or an unknown or unsupported rounding
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289 was specified. These aspects of the context need only be checked when
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290 the values are required to be used. The result is [0,qNaN].
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291 """
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292
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293 def handle(self, context, *args):
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294 return _NaN
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295
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296 class Rounded(DecimalException):
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297 """Number got rounded (not necessarily changed during rounding).
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298
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299 This occurs and signals rounded whenever the result of an operation is
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300 rounded (that is, some zero or non-zero digits were discarded from the
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301 coefficient), or if an overflow or underflow condition occurs. The
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302 result in all cases is unchanged.
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303
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304 The rounded signal may be tested (or trapped) to determine if a given
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305 operation (or sequence of operations) caused a loss of precision.
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306 """
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307
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308 class Subnormal(DecimalException):
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309 """Exponent < Emin before rounding.
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310
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311 This occurs and signals subnormal whenever the result of a conversion or
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312 operation is subnormal (that is, its adjusted exponent is less than
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313 Emin, before any rounding). The result in all cases is unchanged.
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314
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315 The subnormal signal may be tested (or trapped) to determine if a given
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316 or operation (or sequence of operations) yielded a subnormal result.
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317 """
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318
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319 class Overflow(Inexact, Rounded):
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320 """Numerical overflow.
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321
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322 This occurs and signals overflow if the adjusted exponent of a result
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323 (from a conversion or from an operation that is not an attempt to divide
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324 by zero), after rounding, would be greater than the largest value that
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325 can be handled by the implementation (the value Emax).
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326
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327 The result depends on the rounding mode:
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328
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329 For round-half-up and round-half-even (and for round-half-down and
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330 round-up, if implemented), the result of the operation is [sign,inf],
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331 where sign is the sign of the intermediate result. For round-down, the
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332 result is the largest finite number that can be represented in the
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333 current precision, with the sign of the intermediate result. For
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334 round-ceiling, the result is the same as for round-down if the sign of
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335 the intermediate result is 1, or is [0,inf] otherwise. For round-floor,
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336 the result is the same as for round-down if the sign of the intermediate
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337 result is 0, or is [1,inf] otherwise. In all cases, Inexact and Rounded
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338 will also be raised.
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339 """
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340
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341 def handle(self, context, sign, *args):
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342 if context.rounding in (ROUND_HALF_UP, ROUND_HALF_EVEN,
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343 ROUND_HALF_DOWN, ROUND_UP):
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344 return _SignedInfinity[sign]
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345 if sign == 0:
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346 if context.rounding == ROUND_CEILING:
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347 return _SignedInfinity[sign]
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348 return _dec_from_triple(sign, '9'*context.prec,
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349 context.Emax-context.prec+1)
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350 if sign == 1:
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351 if context.rounding == ROUND_FLOOR:
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352 return _SignedInfinity[sign]
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353 return _dec_from_triple(sign, '9'*context.prec,
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354 context.Emax-context.prec+1)
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355
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356
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357 class Underflow(Inexact, Rounded, Subnormal):
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358 """Numerical underflow with result rounded to 0.
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359
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360 This occurs and signals underflow if a result is inexact and the
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361 adjusted exponent of the result would be smaller (more negative) than
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362 the smallest value that can be handled by the implementation (the value
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363 Emin). That is, the result is both inexact and subnormal.
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364
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365 The result after an underflow will be a subnormal number rounded, if
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366 necessary, so that its exponent is not less than Etiny. This may result
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367 in 0 with the sign of the intermediate result and an exponent of Etiny.
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368
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369 In all cases, Inexact, Rounded, and Subnormal will also be raised.
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370 """
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371
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diff changeset
372 # List of public traps and flags
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c13d911ae05b * Rename "Signals" to "_signals" making it non-public.
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373 _signals = [Clamped, DivisionByZero, Inexact, Overflow, Rounded,
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374 Underflow, InvalidOperation, Subnormal]
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375
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376 # Map conditions (per the spec) to signals
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377 _condition_map = {ConversionSyntax:InvalidOperation,
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378 DivisionImpossible:InvalidOperation,
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379 DivisionUndefined:InvalidOperation,
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380 InvalidContext:InvalidOperation}
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381
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382 ##### Context Functions ##################################################
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383
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384 # The getcontext() and setcontext() function manage access to a thread-local
949473fa4828 Use threading.local() instead of threading.currentThread().
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385 # current context. Py2.4 offers direct support for thread locals. If that
949473fa4828 Use threading.local() instead of threading.currentThread().
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386 # is not available, use threading.currentThread() which is slower but will
34184
36cf94f57415 Bug #1083645
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parents: 34023
diff changeset
387 # work for older Pythons. If threads are not part of the build, create a
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1d7da8608031 Revert r50706 (Whitespace normalization) and
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388 # mock threading object with threading.local() returning the module namespace.
34184
36cf94f57415 Bug #1083645
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389
36cf94f57415 Bug #1083645
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parents: 34023
diff changeset
390 try:
36cf94f57415 Bug #1083645
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diff changeset
391 import threading
36cf94f57415 Bug #1083645
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392 except ImportError:
36cf94f57415 Bug #1083645
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393 # Python was compiled without threads; create a mock object instead
36cf94f57415 Bug #1083645
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parents: 34023
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394 import sys
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395 class MockThreading(object):
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396 def local(self, sys=sys):
36cf94f57415 Bug #1083645
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parents: 34023
diff changeset
397 return sys.modules[__name__]
36cf94f57415 Bug #1083645
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parents: 34023
diff changeset
398 threading = MockThreading()
36cf94f57415 Bug #1083645
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parents: 34023
diff changeset
399 del sys, MockThreading
32675
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diff changeset
400
949473fa4828 Use threading.local() instead of threading.currentThread().
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parents: 32674
diff changeset
401 try:
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
402 threading.local
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
403
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
404 except AttributeError:
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
405
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parents: 40770
diff changeset
406 # To fix reloading, force it to create a new context
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
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parents: 40770
diff changeset
407 # Old contexts have different exceptions in their dicts, making problems.
32675
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parents: 32674
diff changeset
408 if hasattr(threading.currentThread(), '__decimal_context__'):
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
409 del threading.currentThread().__decimal_context__
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
410
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
411 def setcontext(context):
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
412 """Set this thread's context to context."""
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
413 if context in (DefaultContext, BasicContext, ExtendedContext):
33044
2749334d71a4 * Context.copy() now makes a deepcopy.
Raymond Hettinger <python@rcn.com>
parents: 32980
diff changeset
414 context = context.copy()
32980
e89ef0bfa1ff SF bug #1002530: test_decimal fails if repeated
Raymond Hettinger <python@rcn.com>
parents: 32675
diff changeset
415 context.clear_flags()
32451
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Raymond Hettinger <python@rcn.com>
parents:
diff changeset
416 threading.currentThread().__decimal_context__ = context
32675
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
417
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
418 def getcontext():
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
419 """Returns this thread's context.
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
420
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
421 If this thread does not yet have a context, returns
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
422 a new context and sets this thread's context.
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
423 New contexts are copies of DefaultContext.
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
424 """
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
425 try:
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
426 return threading.currentThread().__decimal_context__
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
427 except AttributeError:
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
428 context = Context()
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
429 threading.currentThread().__decimal_context__ = context
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
430 return context
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
431
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
432 else:
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
433
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
434 local = threading.local()
33044
2749334d71a4 * Context.copy() now makes a deepcopy.
Raymond Hettinger <python@rcn.com>
parents: 32980
diff changeset
435 if hasattr(local, '__decimal_context__'):
2749334d71a4 * Context.copy() now makes a deepcopy.
Raymond Hettinger <python@rcn.com>
parents: 32980
diff changeset
436 del local.__decimal_context__
32675
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
437
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
438 def getcontext(_local=local):
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
439 """Returns this thread's context.
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
440
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
441 If this thread does not yet have a context, returns
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
442 a new context and sets this thread's context.
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
443 New contexts are copies of DefaultContext.
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
444 """
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
445 try:
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
446 return _local.__decimal_context__
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
447 except AttributeError:
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
448 context = Context()
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
449 _local.__decimal_context__ = context
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
450 return context
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
451
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
452 def setcontext(context, _local=local):
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
453 """Set this thread's context to context."""
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
454 if context in (DefaultContext, BasicContext, ExtendedContext):
33044
2749334d71a4 * Context.copy() now makes a deepcopy.
Raymond Hettinger <python@rcn.com>
parents: 32980
diff changeset
455 context = context.copy()
32980
e89ef0bfa1ff SF bug #1002530: test_decimal fails if repeated
Raymond Hettinger <python@rcn.com>
parents: 32675
diff changeset
456 context.clear_flags()
32675
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
457 _local.__decimal_context__ = context
949473fa4828 Use threading.local() instead of threading.currentThread().
Raymond Hettinger <python@rcn.com>
parents: 32674
diff changeset
458
39120
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
459 del threading, local # Don't contaminate the namespace
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
460
39707
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
461 def localcontext(ctx=None):
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
462 """Return a context manager for a copy of the supplied context
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
463
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
464 Uses a copy of the current context if no context is specified
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
465 The returned context manager creates a local decimal context
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
466 in a with statement:
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
467 def sin(x):
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
468 with localcontext() as ctx:
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
469 ctx.prec += 2
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
470 # Rest of sin calculation algorithm
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
471 # uses a precision 2 greater than normal
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
472 return +s # Convert result to normal precision
39707
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
473
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
474 def sin(x):
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
475 with localcontext(ExtendedContext):
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
476 # Rest of sin calculation algorithm
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
477 # uses the Extended Context from the
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
478 # General Decimal Arithmetic Specification
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
479 return +s # Convert result to normal context
39707
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
480
46625
c4d90fa935ea Fixed some test structures. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 46087
diff changeset
481 >>> setcontext(DefaultContext)
39707
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
482 >>> print getcontext().prec
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
483 28
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
484 >>> with localcontext():
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
485 ... ctx = getcontext()
40770
9f5eaea3c795 Fix docstring bug
Raymond Hettinger <python@rcn.com>
parents: 39724
diff changeset
486 ... ctx.prec += 2
39707
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
487 ... print ctx.prec
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
488 ...
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
489 30
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
490 >>> with localcontext(ExtendedContext):
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
491 ... print getcontext().prec
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
492 ...
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
493 9
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
494 >>> print getcontext().prec
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
495 28
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
496 """
39721
2f086d58ca10 Make decimal.ContextManager a private implementation detail of decimal.localcontext()
Nick Coghlan <ncoghlan@gmail.com>
parents: 39707
diff changeset
497 if ctx is None: ctx = getcontext()
2f086d58ca10 Make decimal.ContextManager a private implementation detail of decimal.localcontext()
Nick Coghlan <ncoghlan@gmail.com>
parents: 39707
diff changeset
498 return _ContextManager(ctx)
39707
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
499
39120
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
500
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
501 ##### Decimal class #######################################################
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
502
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
503 class Decimal(object):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
504 """Floating point class for decimal arithmetic."""
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
505
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
506 __slots__ = ('_exp','_int','_sign', '_is_special')
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
507 # Generally, the value of the Decimal instance is given by
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
508 # (-1)**_sign * _int * 10**_exp
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
509 # Special values are signified by _is_special == True
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
510
33695
924bb2aad4f4 SF patch #1043218
Raymond Hettinger <python@rcn.com>
parents: 33596
diff changeset
511 # We're immutable, so use __new__ not __init__
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
512 def __new__(cls, value="0", context=None):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
513 """Create a decimal point instance.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
514
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
515 >>> Decimal('3.14') # string input
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
516 Decimal('3.14')
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
517 >>> Decimal((0, (3, 1, 4), -2)) # tuple (sign, digit_tuple, exponent)
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
518 Decimal('3.14')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
519 >>> Decimal(314) # int or long
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
520 Decimal('314')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
521 >>> Decimal(Decimal(314)) # another decimal instance
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
522 Decimal('314')
44650
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
523 >>> Decimal(' 3.14 \\n') # leading and trailing whitespace okay
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
524 Decimal('3.14')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
525 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
526
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
527 # Note that the coefficient, self._int, is actually stored as
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
528 # a string rather than as a tuple of digits. This speeds up
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
529 # the "digits to integer" and "integer to digits" conversions
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
530 # that are used in almost every arithmetic operation on
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
531 # Decimals. This is an internal detail: the as_tuple function
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
532 # and the Decimal constructor still deal with tuples of
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
533 # digits.
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
534
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
535 self = object.__new__(cls)
44068
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
536
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
537 # From a string
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
538 # REs insist on real strings, so we can too.
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
539 if isinstance(value, basestring):
44650
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
540 m = _parser(value.strip())
44068
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
541 if m is None:
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
542 if context is None:
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
543 context = getcontext()
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
544 return context._raise_error(ConversionSyntax,
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
545 "Invalid literal for Decimal: %r" % value)
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
546
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
547 if m.group('sign') == "-":
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
548 self._sign = 1
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
549 else:
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
550 self._sign = 0
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
551 intpart = m.group('int')
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
552 if intpart is not None:
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
553 # finite number
55519
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
554 fracpart = m.group('frac') or ''
44068
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
555 exp = int(m.group('exp') or '0')
55519
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
556 self._int = str(int(intpart+fracpart))
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
557 self._exp = exp - len(fracpart)
44068
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Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
558 self._is_special = False
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Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
559 else:
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
560 diag = m.group('diag')
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
561 if diag is not None:
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
562 # NaN
55519
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
563 self._int = str(int(diag or '0')).lstrip('0')
44068
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
564 if m.group('signal'):
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
565 self._exp = 'N'
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
566 else:
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
567 self._exp = 'n'
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
568 else:
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
569 # infinity
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
570 self._int = '0'
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
571 self._exp = 'F'
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
572 self._is_special = True
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
573 return self
139a4012bead SF patch #1020845: Decimal performance enhancements
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parents: 33198
diff changeset
574
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
575 # From an integer
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
576 if isinstance(value, (int,long)):
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
577 if value >= 0:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
578 self._sign = 0
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
579 else:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
580 self._sign = 1
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
581 self._exp = 0
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
582 self._int = str(abs(value))
44068
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
583 self._is_special = False
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Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
584 return self
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
585
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
586 # From another decimal
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
587 if isinstance(value, Decimal):
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
588 self._exp = value._exp
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
589 self._sign = value._sign
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
590 self._int = value._int
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
591 self._is_special = value._is_special
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
592 return self
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
593
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
594 # From an internal working value
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
595 if isinstance(value, _WorkRep):
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
596 self._sign = value.sign
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
597 self._int = str(value.int)
53113106febb Reordering of __new__ to minimize isinstance() calls to most
Facundo Batista <facundobatista@gmail.com>
parents: 43993
diff changeset
598 self._exp = int(value.exp)
53113106febb Reordering of __new__ to minimize isinstance() calls to most
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parents: 43993
diff changeset
599 self._is_special = False
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
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parents: 33198
diff changeset
600 return self
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
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parents:
diff changeset
601
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
602 # tuple/list conversion (possibly from as_tuple())
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
603 if isinstance(value, (list,tuple)):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
604 if len(value) != 3:
43602
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
605 raise ValueError('Invalid tuple size in creation of Decimal '
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
606 'from list or tuple. The list or tuple '
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
607 'should have exactly three elements.')
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
608 # process sign. The isinstance test rejects floats
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
609 if not (isinstance(value[0], (int, long)) and value[0] in (0,1)):
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
610 raise ValueError("Invalid sign. The first value in the tuple "
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
611 "should be an integer; either 0 for a "
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
612 "positive number or 1 for a negative number.")
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
613 self._sign = value[0]
43602
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
614 if value[2] == 'F':
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
615 # infinity: value[1] is ignored
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
616 self._int = '0'
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
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parents:
diff changeset
617 self._exp = value[2]
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
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parents: 33198
diff changeset
618 self._is_special = True
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
619 else:
43602
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
620 # process and validate the digits in value[1]
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
621 digits = []
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
622 for digit in value[1]:
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
623 if isinstance(digit, (int, long)) and 0 <= digit <= 9:
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
624 # skip leading zeros
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
625 if digits or digit != 0:
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
626 digits.append(digit)
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
627 else:
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
628 raise ValueError("The second value in the tuple must "
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
629 "be composed of integers in the range "
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
630 "0 through 9.")
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
631 if value[2] in ('n', 'N'):
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
632 # NaN: digits form the diagnostic
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
633 self._int = ''.join(map(str, digits))
43602
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
634 self._exp = value[2]
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
635 self._is_special = True
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
636 elif isinstance(value[2], (int, long)):
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
637 # finite number: digits give the coefficient
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
638 self._int = ''.join(map(str, digits or [0]))
43602
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
639 self._exp = value[2]
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
640 self._is_special = False
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
641 else:
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
642 raise ValueError("The third value in the tuple must "
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
643 "be an integer, or one of the "
80744c8d34d8 The constructor from tuple was way too permissive: it allowed bad
Facundo Batista <facundobatista@gmail.com>
parents: 43455
diff changeset
644 "strings 'F', 'n', 'N'.")
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
645 return self
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
646
32576
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
647 if isinstance(value, float):
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
648 raise TypeError("Cannot convert float to Decimal. " +
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
649 "First convert the float to a string")
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
650
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
651 raise TypeError("Cannot convert %r to Decimal" % value)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
652
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
653 def _isnan(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
654 """Returns whether the number is not actually one.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
655
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
656 0 if a number
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
657 1 if NaN
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
658 2 if sNaN
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
659 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
660 if self._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
661 exp = self._exp
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
662 if exp == 'n':
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
663 return 1
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
664 elif exp == 'N':
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
665 return 2
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
666 return 0
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
667
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
668 def _isinfinity(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
669 """Returns whether the number is infinite
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
670
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
671 0 if finite or not a number
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
672 1 if +INF
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
673 -1 if -INF
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
674 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
675 if self._exp == 'F':
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
676 if self._sign:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
677 return -1
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
678 return 1
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
679 return 0
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
680
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
681 def _check_nans(self, other=None, context=None):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
682 """Returns whether the number is not actually one.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
683
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
684 if self, other are sNaN, signal
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
685 if self, other are NaN return nan
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
686 return 0
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
687
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
688 Done before operations.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
689 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
690
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
691 self_is_nan = self._isnan()
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
692 if other is None:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
693 other_is_nan = False
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
694 else:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
695 other_is_nan = other._isnan()
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
696
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
697 if self_is_nan or other_is_nan:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
698 if context is None:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
699 context = getcontext()
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
700
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
701 if self_is_nan == 2:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
702 return context._raise_error(InvalidOperation, 'sNaN',
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
703 self)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
704 if other_is_nan == 2:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
705 return context._raise_error(InvalidOperation, 'sNaN',
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
706 other)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
707 if self_is_nan:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
708 return self._fix_nan(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
709
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
710 return other._fix_nan(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
711 return 0
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
712
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
713 def _compare_check_nans(self, other, context):
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
714 """Version of _check_nans used for the signaling comparisons
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
715 compare_signal, __le__, __lt__, __ge__, __gt__.
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
716
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
717 Signal InvalidOperation if either self or other is a (quiet
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
718 or signaling) NaN. Signaling NaNs take precedence over quiet
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
719 NaNs.
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
720
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
721 Return 0 if neither operand is a NaN.
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
722
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
723 """
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
724 if context is None:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
725 context = getcontext()
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
726
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
727 if self._is_special or other._is_special:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
728 if self.is_snan():
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
729 return context._raise_error(InvalidOperation,
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
730 'comparison involving sNaN',
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
731 self)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
732 elif other.is_snan():
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
733 return context._raise_error(InvalidOperation,
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
734 'comparison involving sNaN',
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
735 other)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
736 elif self.is_qnan():
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
737 return context._raise_error(InvalidOperation,
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
738 'comparison involving NaN',
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
739 self)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
740 elif other.is_qnan():
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
741 return context._raise_error(InvalidOperation,
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
742 'comparison involving NaN',
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
743 other)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
744 return 0
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
745
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
746 def __nonzero__(self):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
747 """Return True if self is nonzero; otherwise return False.
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
748
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
749 NaNs and infinities are considered nonzero.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
750 """
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
751 return self._is_special or self._int != '0'
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
752
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
753 def _cmp(self, other):
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
754 """Compare the two non-NaN decimal instances self and other.
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
755
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
756 Returns -1 if self < other, 0 if self == other and 1
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
757 if self > other. This routine is for internal use only."""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
758
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
759 if self._is_special or other._is_special:
51028
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
760 self_inf = self._isinfinity()
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
761 other_inf = other._isinfinity()
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
762 if self_inf == other_inf:
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
763 return 0
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
764 elif self_inf < other_inf:
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
765 return -1
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
766 else:
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
767 return 1
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
768
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
769 # check for zeros; Decimal('0') == Decimal('-0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
770 if not self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
771 if not other:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
772 return 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
773 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
774 return -((-1)**other._sign)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
775 if not other:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
776 return (-1)**self._sign
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
777
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
778 # If different signs, neg one is less
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
779 if other._sign < self._sign:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
780 return -1
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
781 if self._sign < other._sign:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
782 return 1
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
783
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
784 self_adjusted = self.adjusted()
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
785 other_adjusted = other.adjusted()
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
786 if self_adjusted == other_adjusted:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
787 self_padded = self._int + '0'*(self._exp - other._exp)
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
788 other_padded = other._int + '0'*(other._exp - self._exp)
51028
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
789 if self_padded == other_padded:
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
790 return 0
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
791 elif self_padded < other_padded:
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
792 return -(-1)**self._sign
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
793 else:
99c10d647f32 Merged revisions 68920 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50601
diff changeset
794 return (-1)**self._sign
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
795 elif self_adjusted > other_adjusted:
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
796 return (-1)**self._sign
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
797 else: # self_adjusted < other_adjusted
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
798 return -((-1)**self._sign)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
799
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
800 # Note: The Decimal standard doesn't cover rich comparisons for
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
801 # Decimals. In particular, the specification is silent on the
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
802 # subject of what should happen for a comparison involving a NaN.
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
803 # We take the following approach:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
804 #
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
805 # == comparisons involving a NaN always return False
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
806 # != comparisons involving a NaN always return True
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
807 # <, >, <= and >= comparisons involving a (quiet or signaling)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
808 # NaN signal InvalidOperation, and return False if the
45269
fb551c938a59 Typos in decimal comment and documentation
Mark Dickinson <dickinsm@gmail.com>
parents: 45201
diff changeset
809 # InvalidOperation is not trapped.
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
810 #
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
811 # This behavior is designed to conform as closely as possible to
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
812 # that specified by IEEE 754.
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
813
32505
191796b7a054 * Add __eq__ and __ne__ so that things like list.index() work properly
Raymond Hettinger <python@rcn.com>
parents: 32499
diff changeset
814 def __eq__(self, other):
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
815 other = _convert_other(other)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
816 if other is NotImplemented:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
817 return other
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
818 if self.is_nan() or other.is_nan():
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
819 return False
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
820 return self._cmp(other) == 0
32505
191796b7a054 * Add __eq__ and __ne__ so that things like list.index() work properly
Raymond Hettinger <python@rcn.com>
parents: 32499
diff changeset
821
191796b7a054 * Add __eq__ and __ne__ so that things like list.index() work properly
Raymond Hettinger <python@rcn.com>
parents: 32499
diff changeset
822 def __ne__(self, other):
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
823 other = _convert_other(other)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
824 if other is NotImplemented:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
825 return other
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
826 if self.is_nan() or other.is_nan():
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
827 return True
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
828 return self._cmp(other) != 0
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
829
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
830 def __lt__(self, other, context=None):
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
831 other = _convert_other(other)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
832 if other is NotImplemented:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
833 return other
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
834 ans = self._compare_check_nans(other, context)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
835 if ans:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
836 return False
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
837 return self._cmp(other) < 0
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
838
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
839 def __le__(self, other, context=None):
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
840 other = _convert_other(other)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
841 if other is NotImplemented:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
842 return other
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
843 ans = self._compare_check_nans(other, context)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
844 if ans:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
845 return False
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
846 return self._cmp(other) <= 0
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
847
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
848 def __gt__(self, other, context=None):
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
849 other = _convert_other(other)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
850 if other is NotImplemented:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
851 return other
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
852 ans = self._compare_check_nans(other, context)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
853 if ans:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
854 return False
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
855 return self._cmp(other) > 0
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
856
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
857 def __ge__(self, other, context=None):
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
858 other = _convert_other(other)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
859 if other is NotImplemented:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
860 return other
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
861 ans = self._compare_check_nans(other, context)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
862 if ans:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
863 return False
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
864 return self._cmp(other) >= 0
32505
191796b7a054 * Add __eq__ and __ne__ so that things like list.index() work properly
Raymond Hettinger <python@rcn.com>
parents: 32499
diff changeset
865
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
866 def compare(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
867 """Compares one to another.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
868
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
869 -1 => a < b
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
870 0 => a = b
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
871 1 => a > b
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
872 NaN => one is NaN
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
873 Like __cmp__, but returns Decimal instances.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
874 """
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
875 other = _convert_other(other, raiseit=True)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
876
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
877 # Compare(NaN, NaN) = NaN
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
878 if (self._is_special or other and other._is_special):
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
879 ans = self._check_nans(other, context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
880 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
881 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
882
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
883 return Decimal(self._cmp(other))
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
884
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
885 def __hash__(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
886 """x.__hash__() <==> hash(x)"""
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
887 # Decimal integers must hash the same as the ints
44593
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
888 #
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
889 # The hash of a nonspecial noninteger Decimal must depend only
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
890 # on the value of that Decimal, and not on its representation.
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
891 # For example: hash(Decimal('100E-1')) == hash(Decimal('10')).
34758
50509ee96364 Bug #1163325: "special" decimals aren't hashable
Raymond Hettinger <python@rcn.com>
parents: 34638
diff changeset
892 if self._is_special:
50509ee96364 Bug #1163325: "special" decimals aren't hashable
Raymond Hettinger <python@rcn.com>
parents: 34638
diff changeset
893 if self._isnan():
50509ee96364 Bug #1163325: "special" decimals aren't hashable
Raymond Hettinger <python@rcn.com>
parents: 34638
diff changeset
894 raise TypeError('Cannot hash a NaN value.')
50509ee96364 Bug #1163325: "special" decimals aren't hashable
Raymond Hettinger <python@rcn.com>
parents: 34638
diff changeset
895 return hash(str(self))
43409
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
896 if not self:
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
897 return 0
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
898 if self._isinteger():
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
899 op = _WorkRep(self.to_integral_value())
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
900 # to make computation feasible for Decimals with large
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
901 # exponent, we use the fact that hash(n) == hash(m) for
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
902 # any two nonzero integers n and m such that (i) n and m
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
903 # have the same sign, and (ii) n is congruent to m modulo
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
904 # 2**64-1. So we can replace hash((-1)**s*c*10**e) with
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
905 # hash((-1)**s*c*pow(10, e, 2**64-1).
357cf07a23fe Issue #1772851. Optimization of __hash__ to behave better for big big
Facundo Batista <facundobatista@gmail.com>
parents: 43391
diff changeset
906 return hash((-1)**op.sign*op.int*pow(10, op.exp, 2**64-1))
44593
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
907 # The value of a nonzero nonspecial Decimal instance is
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
908 # faithfully represented by the triple consisting of its sign,
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
909 # its adjusted exponent, and its coefficient with trailing
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
910 # zeros removed.
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
911 return hash((self._sign,
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
912 self._exp+len(self._int),
057de46ea17e Issue #1757: The hash of a Decimal instance is no longer affected
Facundo Batista <facundobatista@gmail.com>
parents: 44352
diff changeset
913 self._int.rstrip('0')))
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
914
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
915 def as_tuple(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
916 """Represents the number as a triple tuple.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
917
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
918 To show the internals exactly as they are.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
919 """
44631
3cd9b877eae0 Have Decimal.as_tuple return a named tuple.
Raymond Hettinger <python@rcn.com>
parents: 44593
diff changeset
920 return DecimalTuple(self._sign, tuple(map(int, self._int)), self._exp)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
921
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
922 def __repr__(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
923 """Represents the number as an instance of Decimal."""
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
924 # Invariant: eval(repr(d)) == d
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
925 return "Decimal('%s')" % str(self)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
926
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
927 def __str__(self, eng=False, context=None):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
928 """Return string representation of the number in scientific notation.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
929
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
930 Captures all of the information in the underlying representation.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
931 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
932
44120
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
933 sign = ['', '-'][self._sign]
35113
adf189eb4f58 Apply the _is_special guard.
Raymond Hettinger <python@rcn.com>
parents: 35035
diff changeset
934 if self._is_special:
44120
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
935 if self._exp == 'F':
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
936 return sign + 'Infinity'
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
937 elif self._exp == 'n':
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
938 return sign + 'NaN' + self._int
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
939 else: # self._exp == 'N'
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
940 return sign + 'sNaN' + self._int
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
941
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
942 # number of digits of self._int to left of decimal point
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
943 leftdigits = self._exp + len(self._int)
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
944
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
945 # dotplace is number of digits of self._int to the left of the
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
946 # decimal point in the mantissa of the output string (that is,
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
947 # after adjusting the exponent)
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
948 if self._exp <= 0 and leftdigits > -6:
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
949 # no exponent required
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
950 dotplace = leftdigits
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
951 elif not eng:
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
952 # usual scientific notation: 1 digit on left of the point
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
953 dotplace = 1
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
954 elif self._int == '0':
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
955 # engineering notation, zero
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
956 dotplace = (leftdigits + 1) % 3 - 1
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
957 else:
44120
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
958 # engineering notation, nonzero
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
959 dotplace = (leftdigits - 1) % 3 + 1
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
960
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
961 if dotplace <= 0:
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
962 intpart = '0'
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
963 fracpart = '.' + '0'*(-dotplace) + self._int
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
964 elif dotplace >= len(self._int):
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
965 intpart = self._int+'0'*(dotplace-len(self._int))
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
966 fracpart = ''
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
967 else:
44120
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
968 intpart = self._int[:dotplace]
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
969 fracpart = '.' + self._int[dotplace:]
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
970 if leftdigits == dotplace:
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
971 exp = ''
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
972 else:
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
973 if context is None:
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
974 context = getcontext()
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
975 exp = ['e', 'E'][context.capitals] + "%+d" % (leftdigits-dotplace)
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
976
fe6bedafb46a Speedup and cleaning of __str__. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44068
diff changeset
977 return sign + intpart + fracpart + exp
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
978
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
979 def to_eng_string(self, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
980 """Convert to engineering-type string.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
981
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
982 Engineering notation has an exponent which is a multiple of 3, so there
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
983 are up to 3 digits left of the decimal place.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
984
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
985 Same rules for when in exponential and when as a value as in __str__.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
986 """
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
987 return self.__str__(eng=True, context=context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
988
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
989 def __neg__(self, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
990 """Returns a copy with the sign switched.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
991
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
992 Rounds, if it has reason.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
993 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
994 if self._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
995 ans = self._check_nans(context=context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
996 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
997 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
998
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
999 if not self:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1000 # -Decimal('0') is Decimal('0'), not Decimal('-0')
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
1001 ans = self.copy_abs()
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1002 else:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1003 ans = self.copy_negate()
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1004
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1005 if context is None:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1006 context = getcontext()
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1007 return ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1008
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1009 def __pos__(self, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1010 """Returns a copy, unless it is a sNaN.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1011
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1012 Rounds the number (if more then precision digits)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1013 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1014 if self._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1015 ans = self._check_nans(context=context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1016 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1017 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1018
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1019 if not self:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1020 # + (-0) = 0
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
1021 ans = self.copy_abs()
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1022 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1023 ans = Decimal(self)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1024
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1025 if context is None:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1026 context = getcontext()
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1027 return ans._fix(context)
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1028
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1029 def __abs__(self, round=True, context=None):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1030 """Returns the absolute value of self.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1031
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1032 If the keyword argument 'round' is false, do not round. The
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1033 expression self.__abs__(round=False) is equivalent to
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1034 self.copy_abs().
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1035 """
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1036 if not round:
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1037 return self.copy_abs()
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1038
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1039 if self._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1040 ans = self._check_nans(context=context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1041 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1042 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1043
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1044 if self._sign:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1045 ans = self.__neg__(context=context)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1046 else:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1047 ans = self.__pos__(context=context)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1048
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1049 return ans
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1050
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1051 def __add__(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1052 """Returns self + other.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1053
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1054 -INF + INF (or the reverse) cause InvalidOperation errors.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1055 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1056 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1057 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1058 return other
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1059
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1060 if context is None:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1061 context = getcontext()
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1062
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1063 if self._is_special or other._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1064 ans = self._check_nans(other, context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1065 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1066 return ans
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1067
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1068 if self._isinfinity():
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
1069 # If both INF, same sign => same as both, opposite => error.
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1070 if self._sign != other._sign and other._isinfinity():
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1071 return context._raise_error(InvalidOperation, '-INF + INF')
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1072 return Decimal(self)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1073 if other._isinfinity():
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
1074 return Decimal(other) # Can't both be infinity here
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1075
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1076 exp = min(self._exp, other._exp)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1077 negativezero = 0
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1078 if context.rounding == ROUND_FLOOR and self._sign != other._sign:
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
1079 # If the answer is 0, the sign should be negative, in this case.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1080 negativezero = 1
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1081
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1082 if not self and not other:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1083 sign = min(self._sign, other._sign)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1084 if negativezero:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1085 sign = 1
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1086 ans = _dec_from_triple(sign, '0', exp)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1087 ans = ans._fix(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1088 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1089 if not self:
33845
032f342efcd2 Very few little improvements.
Facundo Batista <facundobatista@gmail.com>
parents: 33803
diff changeset
1090 exp = max(exp, other._exp - context.prec-1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1091 ans = other._rescale(exp, context.rounding)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1092 ans = ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1093 return ans
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1094 if not other:
33845
032f342efcd2 Very few little improvements.
Facundo Batista <facundobatista@gmail.com>
parents: 33803
diff changeset
1095 exp = max(exp, self._exp - context.prec-1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1096 ans = self._rescale(exp, context.rounding)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1097 ans = ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1098 return ans
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1099
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1100 op1 = _WorkRep(self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1101 op2 = _WorkRep(other)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1102 op1, op2 = _normalize(op1, op2, context.prec)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1103
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1104 result = _WorkRep()
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1105 if op1.sign != op2.sign:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1106 # Equal and opposite
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1107 if op1.int == op2.int:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1108 ans = _dec_from_triple(negativezero, '0', exp)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1109 ans = ans._fix(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1110 return ans
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1111 if op1.int < op2.int:
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1112 op1, op2 = op2, op1
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
1113 # OK, now abs(op1) > abs(op2)
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1114 if op1.sign == 1:
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1115 result.sign = 1
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1116 op1.sign, op2.sign = op2.sign, op1.sign
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1117 else:
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1118 result.sign = 0
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
1119 # So we know the sign, and op1 > 0.
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1120 elif op1.sign == 1:
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1121 result.sign = 1
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1122 op1.sign, op2.sign = (0, 0)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1123 else:
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1124 result.sign = 0
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
1125 # Now, op1 > abs(op2) > 0
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1126
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
1127 if op2.sign == 0:
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1128 result.int = op1.int + op2.int
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1129 else:
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1130 result.int = op1.int - op2.int
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1131
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1132 result.exp = op1.exp
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1133 ans = Decimal(result)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1134 ans = ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1135 return ans
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1136
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1137 __radd__ = __add__
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1138
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1139 def __sub__(self, other, context=None):
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1140 """Return self - other"""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1141 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1142 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1143 return other
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1144
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1145 if self._is_special or other._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1146 ans = self._check_nans(other, context=context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1147 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1148 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1149
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1150 # self - other is computed as self + other.copy_negate()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1151 return self.__add__(other.copy_negate(), context=context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1152
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1153 def __rsub__(self, other, context=None):
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1154 """Return other - self"""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1155 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1156 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1157 return other
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1158
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1159 return other.__sub__(self, context=context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1160
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1161 def __mul__(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1162 """Return self * other.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1163
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1164 (+-) INF * 0 (or its reverse) raise InvalidOperation.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1165 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1166 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1167 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1168 return other
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1169
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1170 if context is None:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1171 context = getcontext()
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1172
32561
6f351b1bcf53 * Update the test suite to reflect that ConversionSyntax was no longer
Raymond Hettinger <python@rcn.com>
parents: 32560
diff changeset
1173 resultsign = self._sign ^ other._sign
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1174
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1175 if self._is_special or other._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1176 ans = self._check_nans(other, context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1177 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1178 return ans
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1179
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1180 if self._isinfinity():
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1181 if not other:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1182 return context._raise_error(InvalidOperation, '(+-)INF * 0')
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
1183 return _SignedInfinity[resultsign]
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1184
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1185 if other._isinfinity():
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1186 if not self:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1187 return context._raise_error(InvalidOperation, '0 * (+-)INF')
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
1188 return _SignedInfinity[resultsign]
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1189
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1190 resultexp = self._exp + other._exp
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1191
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1192 # Special case for multiplying by zero
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1193 if not self or not other:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1194 ans = _dec_from_triple(resultsign, '0', resultexp)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1195 # Fixing in case the exponent is out of bounds
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1196 ans = ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1197 return ans
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1198
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1199 # Special case for multiplying by power of 10
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1200 if self._int == '1':
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1201 ans = _dec_from_triple(resultsign, other._int, resultexp)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1202 ans = ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1203 return ans
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1204 if other._int == '1':
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1205 ans = _dec_from_triple(resultsign, self._int, resultexp)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1206 ans = ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1207 return ans
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1208
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1209 op1 = _WorkRep(self)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1210 op2 = _WorkRep(other)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1211
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1212 ans = _dec_from_triple(resultsign, str(op1.int * op2.int), resultexp)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1213 ans = ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1214
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1215 return ans
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1216 __rmul__ = __mul__
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1217
46651
c97e36abcdd5 Some very minor changes to decimal.py in Python 2.6, aimed
Mark Dickinson <dickinsm@gmail.com>
parents: 46643
diff changeset
1218 def __truediv__(self, other, context=None):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1219 """Return self / other."""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1220 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1221 if other is NotImplemented:
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1222 return NotImplemented
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1223
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1224 if context is None:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1225 context = getcontext()
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1226
32561
6f351b1bcf53 * Update the test suite to reflect that ConversionSyntax was no longer
Raymond Hettinger <python@rcn.com>
parents: 32560
diff changeset
1227 sign = self._sign ^ other._sign
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1228
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1229 if self._is_special or other._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1230 ans = self._check_nans(other, context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1231 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1232 return ans
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1233
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1234 if self._isinfinity() and other._isinfinity():
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1235 return context._raise_error(InvalidOperation, '(+-)INF/(+-)INF')
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1236
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1237 if self._isinfinity():
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
1238 return _SignedInfinity[sign]
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1239
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1240 if other._isinfinity():
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1241 context._raise_error(Clamped, 'Division by infinity')
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1242 return _dec_from_triple(sign, '0', context.Etiny())
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1243
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1244 # Special cases for zeroes
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1245 if not other:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1246 if not self:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1247 return context._raise_error(DivisionUndefined, '0 / 0')
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1248 return context._raise_error(DivisionByZero, 'x / 0', sign)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1249
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1250 if not self:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1251 exp = self._exp - other._exp
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1252 coeff = 0
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1253 else:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1254 # OK, so neither = 0, INF or NaN
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1255 shift = len(other._int) - len(self._int) + context.prec + 1
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1256 exp = self._exp - other._exp - shift
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1257 op1 = _WorkRep(self)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1258 op2 = _WorkRep(other)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1259 if shift >= 0:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1260 coeff, remainder = divmod(op1.int * 10**shift, op2.int)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1261 else:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1262 coeff, remainder = divmod(op1.int, op2.int * 10**-shift)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1263 if remainder:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1264 # result is not exact; adjust to ensure correct rounding
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1265 if coeff % 5 == 0:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1266 coeff += 1
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1267 else:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1268 # result is exact; get as close to ideal exponent as possible
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1269 ideal_exp = self._exp - other._exp
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1270 while exp < ideal_exp and coeff % 10 == 0:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1271 coeff //= 10
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1272 exp += 1
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1273
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1274 ans = _dec_from_triple(sign, str(coeff), exp)
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1275 return ans._fix(context)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1276
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1277 def _divide(self, other, context):
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1278 """Return (self // other, self % other), to context.prec precision.
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1279
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1280 Assumes that neither self nor other is a NaN, that self is not
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1281 infinite and that other is nonzero.
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1282 """
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1283 sign = self._sign ^ other._sign
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1284 if other._isinfinity():
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1285 ideal_exp = self._exp
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1286 else:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1287 ideal_exp = min(self._exp, other._exp)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1288
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1289 expdiff = self.adjusted() - other.adjusted()
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1290 if not self or other._isinfinity() or expdiff <= -2:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1291 return (_dec_from_triple(sign, '0', 0),
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1292 self._rescale(ideal_exp, context.rounding))
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1293 if expdiff <= context.prec:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1294 op1 = _WorkRep(self)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1295 op2 = _WorkRep(other)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1296 if op1.exp >= op2.exp:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1297 op1.int *= 10**(op1.exp - op2.exp)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1298 else:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1299 op2.int *= 10**(op2.exp - op1.exp)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1300 q, r = divmod(op1.int, op2.int)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1301 if q < 10**context.prec:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1302 return (_dec_from_triple(sign, str(q), 0),
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1303 _dec_from_triple(self._sign, str(r), ideal_exp))
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1304
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1305 # Here the quotient is too large to be representable
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1306 ans = context._raise_error(DivisionImpossible,
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1307 'quotient too large in //, % or divmod')
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1308 return ans, ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1309
46651
c97e36abcdd5 Some very minor changes to decimal.py in Python 2.6, aimed
Mark Dickinson <dickinsm@gmail.com>
parents: 46643
diff changeset
1310 def __rtruediv__(self, other, context=None):
c97e36abcdd5 Some very minor changes to decimal.py in Python 2.6, aimed
Mark Dickinson <dickinsm@gmail.com>
parents: 46643
diff changeset
1311 """Swaps self/other and returns __truediv__."""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1312 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1313 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1314 return other
46651
c97e36abcdd5 Some very minor changes to decimal.py in Python 2.6, aimed
Mark Dickinson <dickinsm@gmail.com>
parents: 46643
diff changeset
1315 return other.__truediv__(self, context=context)
c97e36abcdd5 Some very minor changes to decimal.py in Python 2.6, aimed
Mark Dickinson <dickinsm@gmail.com>
parents: 46643
diff changeset
1316
c97e36abcdd5 Some very minor changes to decimal.py in Python 2.6, aimed
Mark Dickinson <dickinsm@gmail.com>
parents: 46643
diff changeset
1317 __div__ = __truediv__
c97e36abcdd5 Some very minor changes to decimal.py in Python 2.6, aimed
Mark Dickinson <dickinsm@gmail.com>
parents: 46643
diff changeset
1318 __rdiv__ = __rtruediv__
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1319
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1320 def __divmod__(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1321 """
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1322 Return (self // other, self % other)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1323 """
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1324 other = _convert_other(other)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1325 if other is NotImplemented:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1326 return other
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1327
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1328 if context is None:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1329 context = getcontext()
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1330
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1331 ans = self._check_nans(other, context)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1332 if ans:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1333 return (ans, ans)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1334
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1335 sign = self._sign ^ other._sign
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1336 if self._isinfinity():
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1337 if other._isinfinity():
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1338 ans = context._raise_error(InvalidOperation, 'divmod(INF, INF)')
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1339 return ans, ans
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1340 else:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
1341 return (_SignedInfinity[sign],
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1342 context._raise_error(InvalidOperation, 'INF % x'))
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1343
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1344 if not other:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1345 if not self:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1346 ans = context._raise_error(DivisionUndefined, 'divmod(0, 0)')
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1347 return ans, ans
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1348 else:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1349 return (context._raise_error(DivisionByZero, 'x // 0', sign),
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1350 context._raise_error(InvalidOperation, 'x % 0'))
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1351
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1352 quotient, remainder = self._divide(other, context)
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1353 remainder = remainder._fix(context)
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1354 return quotient, remainder
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1355
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1356 def __rdivmod__(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1357 """Swaps self/other and returns __divmod__."""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1358 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1359 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1360 return other
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1361 return other.__divmod__(self, context=context)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1362
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1363 def __mod__(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1364 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1365 self % other
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1366 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1367 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1368 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1369 return other
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1370
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1371 if context is None:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1372 context = getcontext()
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1373
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1374 ans = self._check_nans(other, context)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1375 if ans:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1376 return ans
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1377
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1378 if self._isinfinity():
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1379 return context._raise_error(InvalidOperation, 'INF % x')
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1380 elif not other:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1381 if self:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1382 return context._raise_error(InvalidOperation, 'x % 0')
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1383 else:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1384 return context._raise_error(DivisionUndefined, '0 % 0')
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1385
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1386 remainder = self._divide(other, context)[1]
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
1387 remainder = remainder._fix(context)
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1388 return remainder
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1389
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1390 def __rmod__(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1391 """Swaps self/other and returns __mod__."""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1392 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1393 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1394 return other
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1395 return other.__mod__(self, context=context)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1396
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1397 def remainder_near(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1398 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1399 Remainder nearest to 0- abs(remainder-near) <= other/2
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1400 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1401 if context is None:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1402 context = getcontext()
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1403
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1404 other = _convert_other(other, raiseit=True)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1405
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1406 ans = self._check_nans(other, context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1407 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1408 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1409
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1410 # self == +/-infinity -> InvalidOperation
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1411 if self._isinfinity():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1412 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1413 'remainder_near(infinity, x)')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1414
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1415 # other == 0 -> either InvalidOperation or DivisionUndefined
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1416 if not other:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1417 if self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1418 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1419 'remainder_near(x, 0)')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1420 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1421 return context._raise_error(DivisionUndefined,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1422 'remainder_near(0, 0)')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1423
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1424 # other = +/-infinity -> remainder = self
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1425 if other._isinfinity():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1426 ans = Decimal(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1427 return ans._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1428
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1429 # self = 0 -> remainder = self, with ideal exponent
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1430 ideal_exponent = min(self._exp, other._exp)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1431 if not self:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1432 ans = _dec_from_triple(self._sign, '0', ideal_exponent)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1433 return ans._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1434
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1435 # catch most cases of large or small quotient
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1436 expdiff = self.adjusted() - other.adjusted()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1437 if expdiff >= context.prec + 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1438 # expdiff >= prec+1 => abs(self/other) > 10**prec
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1439 return context._raise_error(DivisionImpossible)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1440 if expdiff <= -2:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1441 # expdiff <= -2 => abs(self/other) < 0.1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1442 ans = self._rescale(ideal_exponent, context.rounding)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1443 return ans._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1444
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1445 # adjust both arguments to have the same exponent, then divide
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1446 op1 = _WorkRep(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1447 op2 = _WorkRep(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1448 if op1.exp >= op2.exp:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1449 op1.int *= 10**(op1.exp - op2.exp)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1450 else:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1451 op2.int *= 10**(op2.exp - op1.exp)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1452 q, r = divmod(op1.int, op2.int)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1453 # remainder is r*10**ideal_exponent; other is +/-op2.int *
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1454 # 10**ideal_exponent. Apply correction to ensure that
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1455 # abs(remainder) <= abs(other)/2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1456 if 2*r + (q&1) > op2.int:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1457 r -= op2.int
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1458 q += 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1459
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1460 if q >= 10**context.prec:
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1461 return context._raise_error(DivisionImpossible)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1462
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1463 # result has same sign as self unless r is negative
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1464 sign = self._sign
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1465 if r < 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1466 sign = 1-sign
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1467 r = -r
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1468
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1469 ans = _dec_from_triple(sign, str(r), ideal_exponent)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1470 return ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1471
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1472 def __floordiv__(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1473 """self // other"""
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1474 other = _convert_other(other)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1475 if other is NotImplemented:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1476 return other
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1477
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1478 if context is None:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1479 context = getcontext()
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1480
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1481 ans = self._check_nans(other, context)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1482 if ans:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1483 return ans
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1484
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1485 if self._isinfinity():
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1486 if other._isinfinity():
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1487 return context._raise_error(InvalidOperation, 'INF // INF')
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1488 else:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
1489 return _SignedInfinity[self._sign ^ other._sign]
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1490
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1491 if not other:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1492 if self:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1493 return context._raise_error(DivisionByZero, 'x // 0',
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1494 self._sign ^ other._sign)
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1495 else:
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1496 return context._raise_error(DivisionUndefined, '0 // 0')
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1497
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
1498 return self._divide(other, context)[0]
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1499
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1500 def __rfloordiv__(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1501 """Swaps self/other and returns __floordiv__."""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1502 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1503 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
1504 return other
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1505 return other.__floordiv__(self, context=context)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1506
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1507 def __float__(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1508 """Float representation."""
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1509 return float(str(self))
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1510
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1511 def __int__(self):
34638
4a0c202ee789 Fix small grammatical error in a docstring.
Brett Cannon <bcannon@gmail.com>
parents: 34545
diff changeset
1512 """Converts self to an int, truncating if necessary."""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1513 if self._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1514 if self._isnan():
55886
fc9a00799795 Merged revisions 74708 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55874
diff changeset
1515 raise ValueError("Cannot convert NaN to integer")
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1516 elif self._isinfinity():
55886
fc9a00799795 Merged revisions 74708 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55874
diff changeset
1517 raise OverflowError("Cannot convert infinity to integer")
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1518 s = (-1)**self._sign
34023
a8ff6ed856e8 SF bug #1071588 coercing decimal to int doesn't work between -1 and 1
Raymond Hettinger <python@rcn.com>
parents: 33851
diff changeset
1519 if self._exp >= 0:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1520 return s*int(self._int)*10**self._exp
34023
a8ff6ed856e8 SF bug #1071588 coercing decimal to int doesn't work between -1 and 1
Raymond Hettinger <python@rcn.com>
parents: 33851
diff changeset
1521 else:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1522 return s*int(self._int[:self._exp] or '0')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1523
44923
e8efa62eec15 Add support for trunc().
Raymond Hettinger <python@rcn.com>
parents: 44701
diff changeset
1524 __trunc__ = __int__
e8efa62eec15 Add support for trunc().
Raymond Hettinger <python@rcn.com>
parents: 44701
diff changeset
1525
45293
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1526 def real(self):
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1527 return self
50601
2be490abf333 Merged revisions 68317-68318 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50480
diff changeset
1528 real = property(real)
2be490abf333 Merged revisions 68317-68318 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50480
diff changeset
1529
45293
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1530 def imag(self):
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1531 return Decimal(0)
50601
2be490abf333 Merged revisions 68317-68318 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50480
diff changeset
1532 imag = property(imag)
45293
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1533
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1534 def conjugate(self):
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1535 return self
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1536
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1537 def __complex__(self):
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1538 return complex(float(self))
4ca70663a79d Bring decimal a bit closer to the spec for Reals.
Raymond Hettinger <python@rcn.com>
parents: 45269
diff changeset
1539
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1540 def __long__(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1541 """Converts to a long.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1542
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1543 Equivalent to long(int(self))
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1544 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1545 return long(self.__int__())
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1546
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1547 def _fix_nan(self, context):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1548 """Decapitate the payload of a NaN to fit the context"""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1549 payload = self._int
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1550
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1551 # maximum length of payload is precision if _clamp=0,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1552 # precision-1 if _clamp=1.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1553 max_payload_len = context.prec - context._clamp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1554 if len(payload) > max_payload_len:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1555 payload = payload[len(payload)-max_payload_len:].lstrip('0')
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1556 return _dec_from_triple(self._sign, payload, self._exp, True)
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
1557 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1558
33695
924bb2aad4f4 SF patch #1043218
Raymond Hettinger <python@rcn.com>
parents: 33596
diff changeset
1559 def _fix(self, context):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1560 """Round if it is necessary to keep self within prec precision.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1561
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1562 Rounds and fixes the exponent. Does not raise on a sNaN.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1563
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1564 Arguments:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1565 self - Decimal instance
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1566 context - context used.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1567 """
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1568
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1569 if self._is_special:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1570 if self._isnan():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1571 # decapitate payload if necessary
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1572 return self._fix_nan(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1573 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1574 # self is +/-Infinity; return unaltered
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
1575 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1576
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1577 # if self is zero then exponent should be between Etiny and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1578 # Emax if _clamp==0, and between Etiny and Etop if _clamp==1.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1579 Etiny = context.Etiny()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1580 Etop = context.Etop()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1581 if not self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1582 exp_max = [context.Emax, Etop][context._clamp]
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1583 new_exp = min(max(self._exp, Etiny), exp_max)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1584 if new_exp != self._exp:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1585 context._raise_error(Clamped)
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1586 return _dec_from_triple(self._sign, '0', new_exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1587 else:
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
1588 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1589
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1590 # exp_min is the smallest allowable exponent of the result,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1591 # equal to max(self.adjusted()-context.prec+1, Etiny)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1592 exp_min = len(self._int) + self._exp - context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1593 if exp_min > Etop:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1594 # overflow: exp_min > Etop iff self.adjusted() > Emax
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1595 context._raise_error(Inexact)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1596 context._raise_error(Rounded)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1597 return context._raise_error(Overflow, 'above Emax', self._sign)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1598 self_is_subnormal = exp_min < Etiny
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1599 if self_is_subnormal:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1600 context._raise_error(Subnormal)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1601 exp_min = Etiny
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1602
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1603 # round if self has too many digits
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1604 if self._exp < exp_min:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1605 context._raise_error(Rounded)
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1606 digits = len(self._int) + self._exp - exp_min
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1607 if digits < 0:
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1608 self = _dec_from_triple(self._sign, '1', exp_min-1)
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1609 digits = 0
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1610 this_function = getattr(self, self._pick_rounding_function[context.rounding])
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1611 changed = this_function(digits)
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1612 coeff = self._int[:digits] or '0'
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1613 if changed == 1:
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1614 coeff = str(int(coeff)+1)
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1615 ans = _dec_from_triple(self._sign, coeff, exp_min)
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1616
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1617 if changed:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1618 context._raise_error(Inexact)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1619 if self_is_subnormal:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1620 context._raise_error(Underflow)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1621 if not ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1622 # raise Clamped on underflow to 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1623 context._raise_error(Clamped)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1624 elif len(ans._int) == context.prec+1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1625 # we get here only if rescaling rounds the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1626 # cofficient up to exactly 10**context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1627 if ans._exp < Etop:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1628 ans = _dec_from_triple(ans._sign,
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1629 ans._int[:-1], ans._exp+1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1630 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1631 # Inexact and Rounded have already been raised
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1632 ans = context._raise_error(Overflow, 'above Emax',
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1633 self._sign)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1634 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1635
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1636 # fold down if _clamp == 1 and self has too few digits
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1637 if context._clamp == 1 and self._exp > Etop:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1638 context._raise_error(Clamped)
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1639 self_padded = self._int + '0'*(self._exp - Etop)
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1640 return _dec_from_triple(self._sign, self_padded, Etop)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1641
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1642 # here self was representable to begin with; return unchanged
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
1643 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1644
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1645 _pick_rounding_function = {}
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1646
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1647 # for each of the rounding functions below:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1648 # self is a finite, nonzero Decimal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1649 # prec is an integer satisfying 0 <= prec < len(self._int)
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1650 #
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1651 # each function returns either -1, 0, or 1, as follows:
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1652 # 1 indicates that self should be rounded up (away from zero)
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1653 # 0 indicates that self should be truncated, and that all the
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1654 # digits to be truncated are zeros (so the value is unchanged)
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1655 # -1 indicates that there are nonzero digits to be truncated
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1656
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1657 def _round_down(self, prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1658 """Also known as round-towards-0, truncate."""
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1659 if _all_zeros(self._int, prec):
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1660 return 0
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1661 else:
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1662 return -1
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1663
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1664 def _round_up(self, prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1665 """Rounds away from 0."""
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1666 return -self._round_down(prec)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1667
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1668 def _round_half_up(self, prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1669 """Rounds 5 up (away from 0)"""
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1670 if self._int[prec] in '56789':
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1671 return 1
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1672 elif _all_zeros(self._int, prec):
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1673 return 0
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1674 else:
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1675 return -1
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1676
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1677 def _round_half_down(self, prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1678 """Round 5 down"""
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1679 if _exact_half(self._int, prec):
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1680 return -1
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1681 else:
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1682 return self._round_half_up(prec)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1683
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1684 def _round_half_even(self, prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1685 """Round 5 to even, rest to nearest."""
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1686 if _exact_half(self._int, prec) and \
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1687 (prec == 0 or self._int[prec-1] in '02468'):
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1688 return -1
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1689 else:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1690 return self._round_half_up(prec)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1691
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1692 def _round_ceiling(self, prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1693 """Rounds up (not away from 0 if negative.)"""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1694 if self._sign:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1695 return self._round_down(prec)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1696 else:
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1697 return -self._round_down(prec)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1698
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1699 def _round_floor(self, prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1700 """Rounds down (not towards 0 if negative)"""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1701 if not self._sign:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1702 return self._round_down(prec)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1703 else:
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1704 return -self._round_down(prec)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1705
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1706 def _round_05up(self, prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1707 """Round down unless digit prec-1 is 0 or 5."""
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1708 if prec and self._int[prec-1] not in '05':
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1709 return self._round_down(prec)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1710 else:
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
1711 return -self._round_down(prec)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1712
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1713 def fma(self, other, third, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1714 """Fused multiply-add.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1715
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1716 Returns self*other+third with no rounding of the intermediate
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1717 product self*other.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1718
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1719 self and other are multiplied together, with no rounding of
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1720 the result. The third operand is then added to the result,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1721 and a single final rounding is performed.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1722 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1723
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1724 other = _convert_other(other, raiseit=True)
44148
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1725
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1726 # compute product; raise InvalidOperation if either operand is
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1727 # a signaling NaN or if the product is zero times infinity.
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1728 if self._is_special or other._is_special:
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1729 if context is None:
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1730 context = getcontext()
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1731 if self._exp == 'N':
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
1732 return context._raise_error(InvalidOperation, 'sNaN', self)
44148
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1733 if other._exp == 'N':
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
1734 return context._raise_error(InvalidOperation, 'sNaN', other)
44148
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1735 if self._exp == 'n':
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1736 product = self
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1737 elif other._exp == 'n':
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1738 product = other
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1739 elif self._exp == 'F':
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1740 if not other:
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1741 return context._raise_error(InvalidOperation,
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1742 'INF * 0 in fma')
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
1743 product = _SignedInfinity[self._sign ^ other._sign]
44148
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1744 elif other._exp == 'F':
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1745 if not self:
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1746 return context._raise_error(InvalidOperation,
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1747 '0 * INF in fma')
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
1748 product = _SignedInfinity[self._sign ^ other._sign]
44148
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1749 else:
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1750 product = _dec_from_triple(self._sign ^ other._sign,
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1751 str(int(self._int) * int(other._int)),
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1752 self._exp + other._exp)
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1753
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1754 third = _convert_other(third, raiseit=True)
44148
53320d544bc7 fma speedup by avoiding to create a Context. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44121
diff changeset
1755 return product.__add__(third, context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1756
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1757 def _power_modulo(self, other, modulo, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1758 """Three argument version of __pow__"""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1759
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1760 # if can't convert other and modulo to Decimal, raise
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1761 # TypeError; there's no point returning NotImplemented (no
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1762 # equivalent of __rpow__ for three argument pow)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1763 other = _convert_other(other, raiseit=True)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1764 modulo = _convert_other(modulo, raiseit=True)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
1765
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1766 if context is None:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1767 context = getcontext()
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1768
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1769 # deal with NaNs: if there are any sNaNs then first one wins,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1770 # (i.e. behaviour for NaNs is identical to that of fma)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1771 self_is_nan = self._isnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1772 other_is_nan = other._isnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1773 modulo_is_nan = modulo._isnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1774 if self_is_nan or other_is_nan or modulo_is_nan:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1775 if self_is_nan == 2:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1776 return context._raise_error(InvalidOperation, 'sNaN',
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
1777 self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1778 if other_is_nan == 2:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1779 return context._raise_error(InvalidOperation, 'sNaN',
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
1780 other)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1781 if modulo_is_nan == 2:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1782 return context._raise_error(InvalidOperation, 'sNaN',
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
1783 modulo)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1784 if self_is_nan:
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
1785 return self._fix_nan(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1786 if other_is_nan:
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
1787 return other._fix_nan(context)
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
1788 return modulo._fix_nan(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1789
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1790 # check inputs: we apply same restrictions as Python's pow()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1791 if not (self._isinteger() and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1792 other._isinteger() and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1793 modulo._isinteger()):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1794 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1795 'pow() 3rd argument not allowed '
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1796 'unless all arguments are integers')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1797 if other < 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1798 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1799 'pow() 2nd argument cannot be '
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1800 'negative when 3rd argument specified')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1801 if not modulo:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1802 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1803 'pow() 3rd argument cannot be 0')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1804
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1805 # additional restriction for decimal: the modulus must be less
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1806 # than 10**prec in absolute value
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1807 if modulo.adjusted() >= context.prec:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1808 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1809 'insufficient precision: pow() 3rd '
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1810 'argument must not have more than '
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1811 'precision digits')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1812
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1813 # define 0**0 == NaN, for consistency with two-argument pow
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1814 # (even though it hurts!)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1815 if not other and not self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1816 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1817 'at least one of pow() 1st argument '
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1818 'and 2nd argument must be nonzero ;'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1819 '0**0 is not defined')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1820
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1821 # compute sign of result
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1822 if other._iseven():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1823 sign = 0
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
1824 else:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1825 sign = self._sign
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1826
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1827 # convert modulo to a Python integer, and self and other to
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1828 # Decimal integers (i.e. force their exponents to be >= 0)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1829 modulo = abs(int(modulo))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1830 base = _WorkRep(self.to_integral_value())
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1831 exponent = _WorkRep(other.to_integral_value())
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1832
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1833 # compute result using integer pow()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1834 base = (base.int % modulo * pow(10, base.exp, modulo)) % modulo
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1835 for i in xrange(exponent.exp):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1836 base = pow(base, 10, modulo)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1837 base = pow(base, exponent.int, modulo)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1838
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1839 return _dec_from_triple(sign, str(base), 0)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1840
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1841 def _power_exact(self, other, p):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1842 """Attempt to compute self**other exactly.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1843
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1844 Given Decimals self and other and an integer p, attempt to
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1845 compute an exact result for the power self**other, with p
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1846 digits of precision. Return None if self**other is not
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1847 exactly representable in p digits.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1848
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1849 Assumes that elimination of special cases has already been
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1850 performed: self and other must both be nonspecial; self must
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1851 be positive and not numerically equal to 1; other must be
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1852 nonzero. For efficiency, other._exp should not be too large,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1853 so that 10**abs(other._exp) is a feasible calculation."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1854
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1855 # In the comments below, we write x for the value of self and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1856 # y for the value of other. Write x = xc*10**xe and y =
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1857 # yc*10**ye.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1858
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1859 # The main purpose of this method is to identify the *failure*
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1860 # of x**y to be exactly representable with as little effort as
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1861 # possible. So we look for cheap and easy tests that
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1862 # eliminate the possibility of x**y being exact. Only if all
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1863 # these tests are passed do we go on to actually compute x**y.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1864
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1865 # Here's the main idea. First normalize both x and y. We
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1866 # express y as a rational m/n, with m and n relatively prime
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1867 # and n>0. Then for x**y to be exactly representable (at
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1868 # *any* precision), xc must be the nth power of a positive
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1869 # integer and xe must be divisible by n. If m is negative
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1870 # then additionally xc must be a power of either 2 or 5, hence
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1871 # a power of 2**n or 5**n.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1872 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1873 # There's a limit to how small |y| can be: if y=m/n as above
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1874 # then:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1875 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1876 # (1) if xc != 1 then for the result to be representable we
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1877 # need xc**(1/n) >= 2, and hence also xc**|y| >= 2. So
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1878 # if |y| <= 1/nbits(xc) then xc < 2**nbits(xc) <=
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1879 # 2**(1/|y|), hence xc**|y| < 2 and the result is not
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1880 # representable.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1881 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1882 # (2) if xe != 0, |xe|*(1/n) >= 1, so |xe|*|y| >= 1. Hence if
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1883 # |y| < 1/|xe| then the result is not representable.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1884 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1885 # Note that since x is not equal to 1, at least one of (1) and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1886 # (2) must apply. Now |y| < 1/nbits(xc) iff |yc|*nbits(xc) <
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1887 # 10**-ye iff len(str(|yc|*nbits(xc)) <= -ye.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1888 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1889 # There's also a limit to how large y can be, at least if it's
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1890 # positive: the normalized result will have coefficient xc**y,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1891 # so if it's representable then xc**y < 10**p, and y <
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1892 # p/log10(xc). Hence if y*log10(xc) >= p then the result is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1893 # not exactly representable.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1894
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1895 # if len(str(abs(yc*xe)) <= -ye then abs(yc*xe) < 10**-ye,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1896 # so |y| < 1/xe and the result is not representable.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1897 # Similarly, len(str(abs(yc)*xc_bits)) <= -ye implies |y|
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1898 # < 1/nbits(xc).
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1899
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1900 x = _WorkRep(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1901 xc, xe = x.int, x.exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1902 while xc % 10 == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1903 xc //= 10
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1904 xe += 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1905
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1906 y = _WorkRep(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1907 yc, ye = y.int, y.exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1908 while yc % 10 == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1909 yc //= 10
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1910 ye += 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1911
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1912 # case where xc == 1: result is 10**(xe*y), with xe*y
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1913 # required to be an integer
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1914 if xc == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1915 if ye >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1916 exponent = xe*yc*10**ye
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1917 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1918 exponent, remainder = divmod(xe*yc, 10**-ye)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1919 if remainder:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1920 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1921 if y.sign == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1922 exponent = -exponent
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1923 # if other is a nonnegative integer, use ideal exponent
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1924 if other._isinteger() and other._sign == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1925 ideal_exponent = self._exp*int(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1926 zeros = min(exponent-ideal_exponent, p-1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1927 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1928 zeros = 0
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1929 return _dec_from_triple(0, '1' + '0'*zeros, exponent-zeros)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1930
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1931 # case where y is negative: xc must be either a power
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1932 # of 2 or a power of 5.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1933 if y.sign == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1934 last_digit = xc % 10
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1935 if last_digit in (2,4,6,8):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1936 # quick test for power of 2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1937 if xc & -xc != xc:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1938 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1939 # now xc is a power of 2; e is its exponent
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1940 e = _nbits(xc)-1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1941 # find e*y and xe*y; both must be integers
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1942 if ye >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1943 y_as_int = yc*10**ye
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1944 e = e*y_as_int
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1945 xe = xe*y_as_int
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1946 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1947 ten_pow = 10**-ye
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1948 e, remainder = divmod(e*yc, ten_pow)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1949 if remainder:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1950 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1951 xe, remainder = divmod(xe*yc, ten_pow)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1952 if remainder:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1953 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1954
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1955 if e*65 >= p*93: # 93/65 > log(10)/log(5)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1956 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1957 xc = 5**e
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1958
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1959 elif last_digit == 5:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1960 # e >= log_5(xc) if xc is a power of 5; we have
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1961 # equality all the way up to xc=5**2658
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1962 e = _nbits(xc)*28//65
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1963 xc, remainder = divmod(5**e, xc)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1964 if remainder:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1965 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1966 while xc % 5 == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1967 xc //= 5
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1968 e -= 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1969 if ye >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1970 y_as_integer = yc*10**ye
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1971 e = e*y_as_integer
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1972 xe = xe*y_as_integer
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1973 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1974 ten_pow = 10**-ye
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1975 e, remainder = divmod(e*yc, ten_pow)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1976 if remainder:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1977 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1978 xe, remainder = divmod(xe*yc, ten_pow)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1979 if remainder:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1980 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1981 if e*3 >= p*10: # 10/3 > log(10)/log(2)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1982 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1983 xc = 2**e
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1984 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1985 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1986
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1987 if xc >= 10**p:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1988 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1989 xe = -e-xe
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
1990 return _dec_from_triple(0, str(xc), xe)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1991
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1992 # now y is positive; find m and n such that y = m/n
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1993 if ye >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1994 m, n = yc*10**ye, 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1995 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1996 if xe != 0 and len(str(abs(yc*xe))) <= -ye:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1997 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1998 xc_bits = _nbits(xc)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
1999 if xc != 1 and len(str(abs(yc)*xc_bits)) <= -ye:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2000 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2001 m, n = yc, 10**(-ye)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2002 while m % 2 == n % 2 == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2003 m //= 2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2004 n //= 2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2005 while m % 5 == n % 5 == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2006 m //= 5
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2007 n //= 5
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2008
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2009 # compute nth root of xc*10**xe
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2010 if n > 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2011 # if 1 < xc < 2**n then xc isn't an nth power
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2012 if xc != 1 and xc_bits <= n:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2013 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2014
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2015 xe, rem = divmod(xe, n)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2016 if rem != 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2017 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2018
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2019 # compute nth root of xc using Newton's method
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2020 a = 1L << -(-_nbits(xc)//n) # initial estimate
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2021 while True:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2022 q, r = divmod(xc, a**(n-1))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2023 if a <= q:
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2024 break
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2025 else:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2026 a = (a*(n-1) + q)//n
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2027 if not (a == q and r == 0):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2028 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2029 xc = a
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2030
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2031 # now xc*10**xe is the nth root of the original xc*10**xe
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2032 # compute mth power of xc*10**xe
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2033
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2034 # if m > p*100//_log10_lb(xc) then m > p/log10(xc), hence xc**m >
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2035 # 10**p and the result is not representable.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2036 if xc > 1 and m > p*100//_log10_lb(xc):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2037 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2038 xc = xc**m
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2039 xe *= m
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2040 if xc > 10**p:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2041 return None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2042
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2043 # by this point the result *is* exactly representable
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2044 # adjust the exponent to get as close as possible to the ideal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2045 # exponent, if necessary
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2046 str_xc = str(xc)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2047 if other._isinteger() and other._sign == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2048 ideal_exponent = self._exp*int(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2049 zeros = min(xe-ideal_exponent, p-len(str_xc))
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2050 else:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2051 zeros = 0
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2052 return _dec_from_triple(0, str_xc+'0'*zeros, xe-zeros)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2053
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2054 def __pow__(self, other, modulo=None, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2055 """Return self ** other [ % modulo].
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2056
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2057 With two arguments, compute self**other.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2058
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2059 With three arguments, compute (self**other) % modulo. For the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2060 three argument form, the following restrictions on the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2061 arguments hold:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2062
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2063 - all three arguments must be integral
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2064 - other must be nonnegative
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2065 - either self or other (or both) must be nonzero
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2066 - modulo must be nonzero and must have at most p digits,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2067 where p is the context precision.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2068
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2069 If any of these restrictions is violated the InvalidOperation
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2070 flag is raised.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2071
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2072 The result of pow(self, other, modulo) is identical to the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2073 result that would be obtained by computing (self**other) %
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2074 modulo with unbounded precision, but is computed more
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2075 efficiently. It is always exact.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2076 """
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2077
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2078 if modulo is not None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2079 return self._power_modulo(other, modulo, context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2080
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2081 other = _convert_other(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2082 if other is NotImplemented:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2083 return other
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2084
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2085 if context is None:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2086 context = getcontext()
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2087
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2088 # either argument is a NaN => result is NaN
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2089 ans = self._check_nans(other, context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2090 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2091 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2092
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2093 # 0**0 = NaN (!), x**0 = 1 for nonzero x (including +/-Infinity)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2094 if not other:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2095 if not self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2096 return context._raise_error(InvalidOperation, '0 ** 0')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2097 else:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2098 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2099
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2100 # result has sign 1 iff self._sign is 1 and other is an odd integer
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2101 result_sign = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2102 if self._sign == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2103 if other._isinteger():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2104 if not other._iseven():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2105 result_sign = 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2106 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2107 # -ve**noninteger = NaN
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2108 # (-0)**noninteger = 0**noninteger
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2109 if self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2110 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2111 'x ** y with x negative and y not an integer')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2112 # negate self, without doing any unwanted rounding
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2113 self = self.copy_negate()
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2114
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2115 # 0**(+ve or Inf)= 0; 0**(-ve or -Inf) = Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2116 if not self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2117 if other._sign == 0:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2118 return _dec_from_triple(result_sign, '0', 0)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2119 else:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2120 return _SignedInfinity[result_sign]
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2121
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2122 # Inf**(+ve or Inf) = Inf; Inf**(-ve or -Inf) = 0
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2123 if self._isinfinity():
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2124 if other._sign == 0:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2125 return _SignedInfinity[result_sign]
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2126 else:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2127 return _dec_from_triple(result_sign, '0', 0)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2128
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2129 # 1**other = 1, but the choice of exponent and the flags
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2130 # depend on the exponent of self, and on whether other is a
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2131 # positive integer, a negative integer, or neither
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2132 if self == _One:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2133 if other._isinteger():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2134 # exp = max(self._exp*max(int(other), 0),
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2135 # 1-context.prec) but evaluating int(other) directly
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2136 # is dangerous until we know other is small (other
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2137 # could be 1e999999999)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2138 if other._sign == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2139 multiplier = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2140 elif other > context.prec:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2141 multiplier = context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2142 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2143 multiplier = int(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2144
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2145 exp = self._exp * multiplier
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2146 if exp < 1-context.prec:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2147 exp = 1-context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2148 context._raise_error(Rounded)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2149 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2150 context._raise_error(Inexact)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2151 context._raise_error(Rounded)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2152 exp = 1-context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2153
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2154 return _dec_from_triple(result_sign, '1'+'0'*-exp, exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2155
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2156 # compute adjusted exponent of self
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2157 self_adj = self.adjusted()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2158
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2159 # self ** infinity is infinity if self > 1, 0 if self < 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2160 # self ** -infinity is infinity if self < 1, 0 if self > 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2161 if other._isinfinity():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2162 if (other._sign == 0) == (self_adj < 0):
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2163 return _dec_from_triple(result_sign, '0', 0)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2164 else:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2165 return _SignedInfinity[result_sign]
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2166
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2167 # from here on, the result always goes through the call
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2168 # to _fix at the end of this function.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2169 ans = None
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2170
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2171 # crude test to catch cases of extreme overflow/underflow. If
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2172 # log10(self)*other >= 10**bound and bound >= len(str(Emax))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2173 # then 10**bound >= 10**len(str(Emax)) >= Emax+1 and hence
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2174 # self**other >= 10**(Emax+1), so overflow occurs. The test
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2175 # for underflow is similar.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2176 bound = self._log10_exp_bound() + other.adjusted()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2177 if (self_adj >= 0) == (other._sign == 0):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2178 # self > 1 and other +ve, or self < 1 and other -ve
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2179 # possibility of overflow
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2180 if bound >= len(str(context.Emax)):
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2181 ans = _dec_from_triple(result_sign, '1', context.Emax+1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2182 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2183 # self > 1 and other -ve, or self < 1 and other +ve
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2184 # possibility of underflow to 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2185 Etiny = context.Etiny()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2186 if bound >= len(str(-Etiny)):
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2187 ans = _dec_from_triple(result_sign, '1', Etiny-1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2188
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2189 # try for an exact result with precision +1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2190 if ans is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2191 ans = self._power_exact(other, context.prec + 1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2192 if ans is not None and result_sign == 1:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2193 ans = _dec_from_triple(1, ans._int, ans._exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2194
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2195 # usual case: inexact result, x**y computed directly as exp(y*log(x))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2196 if ans is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2197 p = context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2198 x = _WorkRep(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2199 xc, xe = x.int, x.exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2200 y = _WorkRep(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2201 yc, ye = y.int, y.exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2202 if y.sign == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2203 yc = -yc
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2204
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2205 # compute correctly rounded result: start with precision +3,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2206 # then increase precision until result is unambiguously roundable
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2207 extra = 3
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2208 while True:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2209 coeff, exp = _dpower(xc, xe, yc, ye, p+extra)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2210 if coeff % (5*10**(len(str(coeff))-p-1)):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2211 break
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2212 extra += 3
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2213
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2214 ans = _dec_from_triple(result_sign, str(coeff), exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2215
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2216 # the specification says that for non-integer other we need to
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2217 # raise Inexact, even when the result is actually exact. In
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2218 # the same way, we need to raise Underflow here if the result
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2219 # is subnormal. (The call to _fix will take care of raising
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2220 # Rounded and Subnormal, as usual.)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2221 if not other._isinteger():
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2222 context._raise_error(Inexact)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2223 # pad with zeros up to length context.prec+1 if necessary
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2224 if len(ans._int) <= context.prec:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2225 expdiff = context.prec+1 - len(ans._int)
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2226 ans = _dec_from_triple(ans._sign, ans._int+'0'*expdiff,
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2227 ans._exp-expdiff)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2228 if ans.adjusted() < context.Emin:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2229 context._raise_error(Underflow)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2230
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2231 # unlike exp, ln and log10, the power function respects the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2232 # rounding mode; no need to use ROUND_HALF_EVEN here
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2233 ans = ans._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2234 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2235
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2236 def __rpow__(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2237 """Swaps self/other and returns __pow__."""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2238 other = _convert_other(other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
2239 if other is NotImplemented:
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
2240 return other
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2241 return other.__pow__(self, context=context)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2242
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2243 def normalize(self, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2244 """Normalize- strip trailing 0s, change anything equal to 0 to 0e0"""
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2245
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2246 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2247 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2248
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2249 if self._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2250 ans = self._check_nans(context=context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2251 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2252 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2253
33695
924bb2aad4f4 SF patch #1043218
Raymond Hettinger <python@rcn.com>
parents: 33596
diff changeset
2254 dup = self._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2255 if dup._isinfinity():
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2256 return dup
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2257
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2258 if not dup:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2259 return _dec_from_triple(dup._sign, '0', 0)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2260 exp_max = [context.Emax, context.Etop()][context._clamp]
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2261 end = len(dup._int)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2262 exp = dup._exp
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2263 while dup._int[end-1] == '0' and exp < exp_max:
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2264 exp += 1
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2265 end -= 1
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2266 return _dec_from_triple(dup._sign, dup._int[:end], exp)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2267
43362
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2268 def quantize(self, exp, rounding=None, context=None, watchexp=True):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2269 """Quantize self so its exponent is the same as that of exp.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2270
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2271 Similar to self._rescale(exp._exp) but with error checking.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2272 """
43362
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2273 exp = _convert_other(exp, raiseit=True)
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2274
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2275 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2276 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2277 if rounding is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2278 rounding = context.rounding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2279
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2280 if self._is_special or exp._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2281 ans = self._check_nans(exp, context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2282 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2283 return ans
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2284
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2285 if exp._isinfinity() or self._isinfinity():
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2286 if exp._isinfinity() and self._isinfinity():
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2287 return Decimal(self) # if both are inf, it is OK
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2288 return context._raise_error(InvalidOperation,
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2289 'quantize with one INF')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2290
43362
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2291 # if we're not watching exponents, do a simple rescale
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2292 if not watchexp:
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2293 ans = self._rescale(exp._exp, rounding)
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2294 # raise Inexact and Rounded where appropriate
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2295 if ans._exp > self._exp:
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2296 context._raise_error(Rounded)
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2297 if ans != self:
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2298 context._raise_error(Inexact)
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2299 return ans
c8c7a947a641 Put the parameter watchexp back in (changed watchexp from an int
Facundo Batista <facundobatista@gmail.com>
parents: 43360
diff changeset
2300
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2301 # exp._exp should be between Etiny and Emax
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2302 if not (context.Etiny() <= exp._exp <= context.Emax):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2303 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2304 'target exponent out of bounds in quantize')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2305
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2306 if not self:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2307 ans = _dec_from_triple(self._sign, '0', exp._exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2308 return ans._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2309
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2310 self_adjusted = self.adjusted()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2311 if self_adjusted > context.Emax:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2312 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2313 'exponent of quantize result too large for current context')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2314 if self_adjusted - exp._exp + 1 > context.prec:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2315 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2316 'quantize result has too many digits for current context')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2317
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2318 ans = self._rescale(exp._exp, rounding)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2319 if ans.adjusted() > context.Emax:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2320 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2321 'exponent of quantize result too large for current context')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2322 if len(ans._int) > context.prec:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2323 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2324 'quantize result has too many digits for current context')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2325
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2326 # raise appropriate flags
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2327 if ans._exp > self._exp:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2328 context._raise_error(Rounded)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2329 if ans != self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2330 context._raise_error(Inexact)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2331 if ans and ans.adjusted() < context.Emin:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2332 context._raise_error(Subnormal)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2333
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2334 # call to fix takes care of any necessary folddown
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2335 ans = ans._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2336 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2337
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2338 def same_quantum(self, other):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2339 """Return True if self and other have the same exponent; otherwise
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2340 return False.
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2341
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2342 If either operand is a special value, the following rules are used:
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2343 * return True if both operands are infinities
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2344 * return True if both operands are NaNs
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2345 * otherwise, return False.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2346 """
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2347 other = _convert_other(other, raiseit=True)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2348 if self._is_special or other._is_special:
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2349 return (self.is_nan() and other.is_nan() or
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2350 self.is_infinite() and other.is_infinite())
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2351 return self._exp == other._exp
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2352
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2353 def _rescale(self, exp, rounding):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2354 """Rescale self so that the exponent is exp, either by padding with zeros
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2355 or by truncating digits, using the given rounding mode.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2356
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2357 Specials are returned without change. This operation is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2358 quiet: it raises no flags, and uses no information from the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2359 context.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2360
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2361 exp = exp to scale to (an integer)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2362 rounding = rounding mode
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2363 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2364 if self._is_special:
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2365 return Decimal(self)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2366 if not self:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2367 return _dec_from_triple(self._sign, '0', exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2368
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2369 if self._exp >= exp:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2370 # pad answer with zeros if necessary
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2371 return _dec_from_triple(self._sign,
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2372 self._int + '0'*(self._exp - exp), exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2373
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2374 # too many digits; round and lose data. If self.adjusted() <
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2375 # exp-1, replace self by 10**(exp-1) before rounding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2376 digits = len(self._int) + self._exp - exp
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2377 if digits < 0:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2378 self = _dec_from_triple(self._sign, '1', exp-1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2379 digits = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2380 this_function = getattr(self, self._pick_rounding_function[rounding])
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
2381 changed = this_function(digits)
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
2382 coeff = self._int[:digits] or '0'
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
2383 if changed == 1:
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
2384 coeff = str(int(coeff)+1)
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
2385 return _dec_from_triple(self._sign, coeff, exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2386
45566
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2387 def _round(self, places, rounding):
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2388 """Round a nonzero, nonspecial Decimal to a fixed number of
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2389 significant figures, using the given rounding mode.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2390
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2391 Infinities, NaNs and zeros are returned unaltered.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2392
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2393 This operation is quiet: it raises no flags, and uses no
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2394 information from the context.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2395
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2396 """
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2397 if places <= 0:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2398 raise ValueError("argument should be at least 1 in _round")
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2399 if self._is_special or not self:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2400 return Decimal(self)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2401 ans = self._rescale(self.adjusted()+1-places, rounding)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2402 # it can happen that the rescale alters the adjusted exponent;
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2403 # for example when rounding 99.97 to 3 significant figures.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2404 # When this happens we end up with an extra 0 at the end of
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2405 # the number; a second rescale fixes this.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2406 if ans.adjusted() != self.adjusted():
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2407 ans = ans._rescale(ans.adjusted()+1-places, rounding)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2408 return ans
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
2409
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2410 def to_integral_exact(self, rounding=None, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2411 """Rounds to a nearby integer.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2412
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2413 If no rounding mode is specified, take the rounding mode from
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2414 the context. This method raises the Rounded and Inexact flags
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2415 when appropriate.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2416
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2417 See also: to_integral_value, which does exactly the same as
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2418 this method except that it doesn't raise Inexact or Rounded.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2419 """
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2420 if self._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2421 ans = self._check_nans(context=context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2422 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2423 return ans
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2424 return Decimal(self)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2425 if self._exp >= 0:
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2426 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2427 if not self:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2428 return _dec_from_triple(self._sign, '0', 0)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2429 if context is None:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2430 context = getcontext()
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2431 if rounding is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2432 rounding = context.rounding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2433 context._raise_error(Rounded)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2434 ans = self._rescale(0, rounding)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2435 if ans != self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2436 context._raise_error(Inexact)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2437 return ans
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2438
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2439 def to_integral_value(self, rounding=None, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2440 """Rounds to the nearest integer, without raising inexact, rounded."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2441 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2442 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2443 if rounding is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2444 rounding = context.rounding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2445 if self._is_special:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2446 ans = self._check_nans(context=context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2447 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2448 return ans
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2449 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2450 if self._exp >= 0:
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2451 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2452 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2453 return self._rescale(0, rounding)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2454
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2455 # the method name changed, but we provide also the old one, for compatibility
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2456 to_integral = to_integral_value
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2457
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2458 def sqrt(self, context=None):
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2459 """Return the square root of self."""
46082
22bd02293efa Issue #2478: Decimal(sqrt(0)) failed when the decimal context
Mark Dickinson <dickinsm@gmail.com>
parents: 45568
diff changeset
2460 if context is None:
22bd02293efa Issue #2478: Decimal(sqrt(0)) failed when the decimal context
Mark Dickinson <dickinsm@gmail.com>
parents: 45568
diff changeset
2461 context = getcontext()
22bd02293efa Issue #2478: Decimal(sqrt(0)) failed when the decimal context
Mark Dickinson <dickinsm@gmail.com>
parents: 45568
diff changeset
2462
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2463 if self._is_special:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2464 ans = self._check_nans(context=context)
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2465 if ans:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2466 return ans
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2467
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2468 if self._isinfinity() and self._sign == 0:
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2469 return Decimal(self)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2470
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2471 if not self:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2472 # exponent = self._exp // 2. sqrt(-0) = -0
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2473 ans = _dec_from_triple(self._sign, '0', self._exp // 2)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2474 return ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2475
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2476 if self._sign == 1:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2477 return context._raise_error(InvalidOperation, 'sqrt(-x), x > 0')
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2478
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2479 # At this point self represents a positive number. Let p be
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2480 # the desired precision and express self in the form c*100**e
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2481 # with c a positive real number and e an integer, c and e
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2482 # being chosen so that 100**(p-1) <= c < 100**p. Then the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2483 # (exact) square root of self is sqrt(c)*10**e, and 10**(p-1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2484 # <= sqrt(c) < 10**p, so the closest representable Decimal at
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2485 # precision p is n*10**e where n = round_half_even(sqrt(c)),
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2486 # the closest integer to sqrt(c) with the even integer chosen
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2487 # in the case of a tie.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2488 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2489 # To ensure correct rounding in all cases, we use the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2490 # following trick: we compute the square root to an extra
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2491 # place (precision p+1 instead of precision p), rounding down.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2492 # Then, if the result is inexact and its last digit is 0 or 5,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2493 # we increase the last digit to 1 or 6 respectively; if it's
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2494 # exact we leave the last digit alone. Now the final round to
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2495 # p places (or fewer in the case of underflow) will round
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2496 # correctly and raise the appropriate flags.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2497
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2498 # use an extra digit of precision
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2499 prec = context.prec+1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2500
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2501 # write argument in the form c*100**e where e = self._exp//2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2502 # is the 'ideal' exponent, to be used if the square root is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2503 # exactly representable. l is the number of 'digits' of c in
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2504 # base 100, so that 100**(l-1) <= c < 100**l.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2505 op = _WorkRep(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2506 e = op.exp >> 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2507 if op.exp & 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2508 c = op.int * 10
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2509 l = (len(self._int) >> 1) + 1
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2510 else:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2511 c = op.int
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2512 l = len(self._int)+1 >> 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2513
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2514 # rescale so that c has exactly prec base 100 'digits'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2515 shift = prec-l
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2516 if shift >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2517 c *= 100**shift
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2518 exact = True
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2519 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2520 c, remainder = divmod(c, 100**-shift)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2521 exact = not remainder
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2522 e -= shift
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2523
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2524 # find n = floor(sqrt(c)) using Newton's method
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2525 n = 10**prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2526 while True:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2527 q = c//n
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2528 if n <= q:
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2529 break
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2530 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2531 n = n + q >> 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2532 exact = exact and n*n == c
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2533
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2534 if exact:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2535 # result is exact; rescale to use ideal exponent e
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2536 if shift >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2537 # assert n % 10**shift == 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2538 n //= 10**shift
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2539 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2540 n *= 10**-shift
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2541 e += shift
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2542 else:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2543 # result is not exact; fix last digit as described above
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2544 if n % 5 == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2545 n += 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2546
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2547 ans = _dec_from_triple(0, str(n), e)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2548
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2549 # round, and fit to current context
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2550 context = context._shallow_copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2551 rounding = context._set_rounding(ROUND_HALF_EVEN)
33695
924bb2aad4f4 SF patch #1043218
Raymond Hettinger <python@rcn.com>
parents: 33596
diff changeset
2552 ans = ans._fix(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2553 context.rounding = rounding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2554
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2555 return ans
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2556
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2557 def max(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2558 """Returns the larger value.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2559
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2560 Like max(self, other) except if one is not a number, returns
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2561 NaN (and signals if one is sNaN). Also rounds.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2562 """
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2563 other = _convert_other(other, raiseit=True)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2564
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2565 if context is None:
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2566 context = getcontext()
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2567
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2568 if self._is_special or other._is_special:
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
2569 # If one operand is a quiet NaN and the other is number, then the
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2570 # number is always returned
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2571 sn = self._isnan()
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2572 on = other._isnan()
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2573 if sn or on:
50116
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
2574 if on == 1 and sn == 0:
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
2575 return self._fix(context)
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
2576 if sn == 1 and on == 0:
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
2577 return other._fix(context)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2578 return self._check_nans(other, context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2579
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
2580 c = self._cmp(other)
33157
b2f427db228b Revise max() and min() to comply with the 8/2/2004 update to the specification
Raymond Hettinger <python@rcn.com>
parents: 33044
diff changeset
2581 if c == 0:
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
2582 # If both operands are finite and equal in numerical value
33157
b2f427db228b Revise max() and min() to comply with the 8/2/2004 update to the specification
Raymond Hettinger <python@rcn.com>
parents: 33044
diff changeset
2583 # then an ordering is applied:
b2f427db228b Revise max() and min() to comply with the 8/2/2004 update to the specification
Raymond Hettinger <python@rcn.com>
parents: 33044
diff changeset
2584 #
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
2585 # If the signs differ then max returns the operand with the
33157
b2f427db228b Revise max() and min() to comply with the 8/2/2004 update to the specification
Raymond Hettinger <python@rcn.com>
parents: 33044
diff changeset
2586 # positive sign and min returns the operand with the negative sign
b2f427db228b Revise max() and min() to comply with the 8/2/2004 update to the specification
Raymond Hettinger <python@rcn.com>
parents: 33044
diff changeset
2587 #
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
2588 # If the signs are the same then the exponent is used to select
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2589 # the result. This is exactly the ordering used in compare_total.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2590 c = self.compare_total(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2591
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2592 if c == -1:
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2593 ans = other
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2594 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2595 ans = self
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2596
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
2597 return ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2598
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2599 def min(self, other, context=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2600 """Returns the smaller value.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2601
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
2602 Like min(self, other) except if one is not a number, returns
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2603 NaN (and signals if one is sNaN). Also rounds.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2604 """
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2605 other = _convert_other(other, raiseit=True)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2606
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2607 if context is None:
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2608 context = getcontext()
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
2609
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2610 if self._is_special or other._is_special:
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
2611 # If one operand is a quiet NaN and the other is number, then the
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2612 # number is always returned
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2613 sn = self._isnan()
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2614 on = other._isnan()
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2615 if sn or on:
50116
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
2616 if on == 1 and sn == 0:
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
2617 return self._fix(context)
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
2618 if sn == 1 and on == 0:
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
2619 return other._fix(context)
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2620 return self._check_nans(other, context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2621
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
2622 c = self._cmp(other)
33157
b2f427db228b Revise max() and min() to comply with the 8/2/2004 update to the specification
Raymond Hettinger <python@rcn.com>
parents: 33044
diff changeset
2623 if c == 0:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2624 c = self.compare_total(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2625
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2626 if c == -1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2627 ans = self
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2628 else:
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2629 ans = other
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
2630
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
2631 return ans._fix(context)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2632
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2633 def _isinteger(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2634 """Returns whether self is an integer"""
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2635 if self._is_special:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2636 return False
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2637 if self._exp >= 0:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2638 return True
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2639 rest = self._int[self._exp:]
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2640 return rest == '0'*len(rest)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2641
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2642 def _iseven(self):
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2643 """Returns True if self is even. Assumes self is an integer."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2644 if not self or self._exp > 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2645 return True
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2646 return self._int[-1+self._exp] in '02468'
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2647
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2648 def adjusted(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2649 """Return the adjusted exponent of self"""
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2650 try:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2651 return self._exp + len(self._int) - 1
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
2652 # If NaN or Infinity, self._exp is string
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2653 except TypeError:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2654 return 0
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
2655
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2656 def canonical(self, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2657 """Returns the same Decimal object.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2658
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2659 As we do not have different encodings for the same number, the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2660 received object already is in its canonical form.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2661 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2662 return self
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2663
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2664 def compare_signal(self, other, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2665 """Compares self to the other operand numerically.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2666
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2667 It's pretty much like compare(), but all NaNs signal, with signaling
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2668 NaNs taking precedence over quiet NaNs.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2669 """
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
2670 other = _convert_other(other, raiseit = True)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
2671 ans = self._compare_check_nans(other, context)
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
2672 if ans:
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
2673 return ans
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2674 return self.compare(other, context=context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2675
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2676 def compare_total(self, other):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2677 """Compares self to other using the abstract representations.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2678
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2679 This is not like the standard compare, which use their numerical
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2680 value. Note that a total ordering is defined for all possible abstract
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2681 representations.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2682 """
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
2683 other = _convert_other(other, raiseit=True)
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
2684
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2685 # if one is negative and the other is positive, it's easy
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2686 if self._sign and not other._sign:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2687 return _NegativeOne
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2688 if not self._sign and other._sign:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2689 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2690 sign = self._sign
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2691
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2692 # let's handle both NaN types
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2693 self_nan = self._isnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2694 other_nan = other._isnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2695 if self_nan or other_nan:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2696 if self_nan == other_nan:
55741
1f1b4c03e892 Merged revisions 74564 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55519
diff changeset
2697 # compare payloads as though they're integers
1f1b4c03e892 Merged revisions 74564 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55519
diff changeset
2698 self_key = len(self._int), self._int
1f1b4c03e892 Merged revisions 74564 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55519
diff changeset
2699 other_key = len(other._int), other._int
1f1b4c03e892 Merged revisions 74564 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55519
diff changeset
2700 if self_key < other_key:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2701 if sign:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2702 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2703 else:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2704 return _NegativeOne
55741
1f1b4c03e892 Merged revisions 74564 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55519
diff changeset
2705 if self_key > other_key:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2706 if sign:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2707 return _NegativeOne
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2708 else:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2709 return _One
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2710 return _Zero
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2711
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2712 if sign:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2713 if self_nan == 1:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2714 return _NegativeOne
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2715 if other_nan == 1:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2716 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2717 if self_nan == 2:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2718 return _NegativeOne
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2719 if other_nan == 2:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2720 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2721 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2722 if self_nan == 1:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2723 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2724 if other_nan == 1:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2725 return _NegativeOne
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2726 if self_nan == 2:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2727 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2728 if other_nan == 2:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2729 return _NegativeOne
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2730
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2731 if self < other:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2732 return _NegativeOne
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2733 if self > other:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2734 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2735
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2736 if self._exp < other._exp:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2737 if sign:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2738 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2739 else:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2740 return _NegativeOne
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2741 if self._exp > other._exp:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2742 if sign:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2743 return _NegativeOne
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2744 else:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2745 return _One
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2746 return _Zero
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2747
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2748
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2749 def compare_total_mag(self, other):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2750 """Compares self to other using abstract repr., ignoring sign.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2751
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2752 Like compare_total, but with operand's sign ignored and assumed to be 0.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2753 """
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
2754 other = _convert_other(other, raiseit=True)
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
2755
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2756 s = self.copy_abs()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2757 o = other.copy_abs()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2758 return s.compare_total(o)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2759
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2760 def copy_abs(self):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2761 """Returns a copy with the sign set to 0. """
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2762 return _dec_from_triple(0, self._int, self._exp, self._is_special)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2763
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2764 def copy_negate(self):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2765 """Returns a copy with the sign inverted."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2766 if self._sign:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2767 return _dec_from_triple(0, self._int, self._exp, self._is_special)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2768 else:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2769 return _dec_from_triple(1, self._int, self._exp, self._is_special)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2770
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2771 def copy_sign(self, other):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2772 """Returns self with the sign of other."""
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2773 return _dec_from_triple(other._sign, self._int,
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2774 self._exp, self._is_special)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2775
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2776 def exp(self, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2777 """Returns e ** self."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2778
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2779 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2780 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2781
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2782 # exp(NaN) = NaN
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2783 ans = self._check_nans(context=context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2784 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2785 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2786
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2787 # exp(-Infinity) = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2788 if self._isinfinity() == -1:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2789 return _Zero
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2790
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2791 # exp(0) = 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2792 if not self:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2793 return _One
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2794
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2795 # exp(Infinity) = Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2796 if self._isinfinity() == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2797 return Decimal(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2798
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2799 # the result is now guaranteed to be inexact (the true
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2800 # mathematical result is transcendental). There's no need to
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2801 # raise Rounded and Inexact here---they'll always be raised as
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2802 # a result of the call to _fix.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2803 p = context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2804 adj = self.adjusted()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2805
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2806 # we only need to do any computation for quite a small range
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2807 # of adjusted exponents---for example, -29 <= adj <= 10 for
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2808 # the default context. For smaller exponent the result is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2809 # indistinguishable from 1 at the given precision, while for
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2810 # larger exponent the result either overflows or underflows.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2811 if self._sign == 0 and adj > len(str((context.Emax+1)*3)):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2812 # overflow
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2813 ans = _dec_from_triple(0, '1', context.Emax+1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2814 elif self._sign == 1 and adj > len(str((-context.Etiny()+1)*3)):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2815 # underflow to 0
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2816 ans = _dec_from_triple(0, '1', context.Etiny()-1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2817 elif self._sign == 0 and adj < -p:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2818 # p+1 digits; final round will raise correct flags
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2819 ans = _dec_from_triple(0, '1' + '0'*(p-1) + '1', -p)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2820 elif self._sign == 1 and adj < -p-1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2821 # p+1 digits; final round will raise correct flags
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2822 ans = _dec_from_triple(0, '9'*(p+1), -p-1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2823 # general case
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2824 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2825 op = _WorkRep(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2826 c, e = op.int, op.exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2827 if op.sign == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2828 c = -c
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2829
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2830 # compute correctly rounded result: increase precision by
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2831 # 3 digits at a time until we get an unambiguously
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2832 # roundable result
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2833 extra = 3
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2834 while True:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2835 coeff, exp = _dexp(c, e, p+extra)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2836 if coeff % (5*10**(len(str(coeff))-p-1)):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2837 break
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2838 extra += 3
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2839
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2840 ans = _dec_from_triple(0, str(coeff), exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2841
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2842 # at this stage, ans should round correctly with *any*
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2843 # rounding mode, not just with ROUND_HALF_EVEN
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2844 context = context._shallow_copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2845 rounding = context._set_rounding(ROUND_HALF_EVEN)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2846 ans = ans._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2847 context.rounding = rounding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2848
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2849 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2850
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2851 def is_canonical(self):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2852 """Return True if self is canonical; otherwise return False.
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2853
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2854 Currently, the encoding of a Decimal instance is always
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2855 canonical, so this method returns True for any Decimal.
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2856 """
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2857 return True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2858
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2859 def is_finite(self):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2860 """Return True if self is finite; otherwise return False.
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2861
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2862 A Decimal instance is considered finite if it is neither
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2863 infinite nor a NaN.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2864 """
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2865 return not self._is_special
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2866
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2867 def is_infinite(self):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2868 """Return True if self is infinite; otherwise return False."""
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2869 return self._exp == 'F'
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2870
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2871 def is_nan(self):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2872 """Return True if self is a qNaN or sNaN; otherwise return False."""
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2873 return self._exp in ('n', 'N')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2874
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2875 def is_normal(self, context=None):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2876 """Return True if self is a normal number; otherwise return False."""
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2877 if self._is_special or not self:
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2878 return False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2879 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2880 context = getcontext()
56854
59505e7e7073 Merged revisions 75561 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56836
diff changeset
2881 return context.Emin <= self.adjusted()
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2882
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2883 def is_qnan(self):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2884 """Return True if self is a quiet NaN; otherwise return False."""
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2885 return self._exp == 'n'
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2886
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2887 def is_signed(self):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2888 """Return True if self is negative; otherwise return False."""
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2889 return self._sign == 1
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2890
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2891 def is_snan(self):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2892 """Return True if self is a signaling NaN; otherwise return False."""
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2893 return self._exp == 'N'
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2894
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2895 def is_subnormal(self, context=None):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2896 """Return True if self is subnormal; otherwise return False."""
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2897 if self._is_special or not self:
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2898 return False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2899 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2900 context = getcontext()
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2901 return self.adjusted() < context.Emin
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2902
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2903 def is_zero(self):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
2904 """Return True if self is a zero; otherwise return False."""
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2905 return not self._is_special and self._int == '0'
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2906
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2907 def _ln_exp_bound(self):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2908 """Compute a lower bound for the adjusted exponent of self.ln().
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2909 In other words, compute r such that self.ln() >= 10**r. Assumes
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2910 that self is finite and positive and that self != 1.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2911 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2912
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2913 # for 0.1 <= x <= 10 we use the inequalities 1-1/x <= ln(x) <= x-1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2914 adj = self._exp + len(self._int) - 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2915 if adj >= 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2916 # argument >= 10; we use 23/10 = 2.3 as a lower bound for ln(10)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2917 return len(str(adj*23//10)) - 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2918 if adj <= -2:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2919 # argument <= 0.1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2920 return len(str((-1-adj)*23//10)) - 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2921 op = _WorkRep(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2922 c, e = op.int, op.exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2923 if adj == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2924 # 1 < self < 10
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2925 num = str(c-10**-e)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2926 den = str(c)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2927 return len(num) - len(den) - (num < den)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2928 # adj == -1, 0.1 <= self < 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2929 return e + len(str(10**-e - c)) - 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2930
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2931
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2932 def ln(self, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2933 """Returns the natural (base e) logarithm of self."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2934
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2935 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2936 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2937
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2938 # ln(NaN) = NaN
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2939 ans = self._check_nans(context=context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2940 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2941 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2942
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2943 # ln(0.0) == -Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2944 if not self:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2945 return _NegativeInfinity
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2946
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2947 # ln(Infinity) = Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2948 if self._isinfinity() == 1:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2949 return _Infinity
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2950
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2951 # ln(1.0) == 0.0
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2952 if self == _One:
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
2953 return _Zero
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2954
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2955 # ln(negative) raises InvalidOperation
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2956 if self._sign == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2957 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2958 'ln of a negative value')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2959
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2960 # result is irrational, so necessarily inexact
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2961 op = _WorkRep(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2962 c, e = op.int, op.exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2963 p = context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2964
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2965 # correctly rounded result: repeatedly increase precision by 3
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2966 # until we get an unambiguously roundable result
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2967 places = p - self._ln_exp_bound() + 2 # at least p+3 places
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2968 while True:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2969 coeff = _dlog(c, e, places)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2970 # assert len(str(abs(coeff)))-p >= 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2971 if coeff % (5*10**(len(str(abs(coeff)))-p-1)):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2972 break
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2973 places += 3
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
2974 ans = _dec_from_triple(int(coeff<0), str(abs(coeff)), -places)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2975
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2976 context = context._shallow_copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2977 rounding = context._set_rounding(ROUND_HALF_EVEN)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2978 ans = ans._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2979 context.rounding = rounding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2980 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2981
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2982 def _log10_exp_bound(self):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2983 """Compute a lower bound for the adjusted exponent of self.log10().
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2984 In other words, find r such that self.log10() >= 10**r.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2985 Assumes that self is finite and positive and that self != 1.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2986 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2987
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2988 # For x >= 10 or x < 0.1 we only need a bound on the integer
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2989 # part of log10(self), and this comes directly from the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2990 # exponent of x. For 0.1 <= x <= 10 we use the inequalities
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2991 # 1-1/x <= log(x) <= x-1. If x > 1 we have |log10(x)| >
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2992 # (1-1/x)/2.31 > 0. If x < 1 then |log10(x)| > (1-x)/2.31 > 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2993
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2994 adj = self._exp + len(self._int) - 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2995 if adj >= 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2996 # self >= 10
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2997 return len(str(adj))-1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2998 if adj <= -2:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
2999 # self < 0.1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3000 return len(str(-1-adj))-1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3001 op = _WorkRep(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3002 c, e = op.int, op.exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3003 if adj == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3004 # 1 < self < 10
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3005 num = str(c-10**-e)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3006 den = str(231*c)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3007 return len(num) - len(den) - (num < den) + 2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3008 # adj == -1, 0.1 <= self < 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3009 num = str(10**-e-c)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3010 return len(num) + e - (num < "231") - 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3011
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3012 def log10(self, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3013 """Returns the base 10 logarithm of self."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3014
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3015 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3016 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3017
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3018 # log10(NaN) = NaN
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3019 ans = self._check_nans(context=context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3020 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3021 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3022
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3023 # log10(0.0) == -Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3024 if not self:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
3025 return _NegativeInfinity
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3026
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3027 # log10(Infinity) = Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3028 if self._isinfinity() == 1:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
3029 return _Infinity
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3030
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3031 # log10(negative or -Infinity) raises InvalidOperation
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3032 if self._sign == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3033 return context._raise_error(InvalidOperation,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3034 'log10 of a negative value')
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3035
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3036 # log10(10**n) = n
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3037 if self._int[0] == '1' and self._int[1:] == '0'*(len(self._int) - 1):
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3038 # answer may need rounding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3039 ans = Decimal(self._exp + len(self._int) - 1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3040 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3041 # result is irrational, so necessarily inexact
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3042 op = _WorkRep(self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3043 c, e = op.int, op.exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3044 p = context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3045
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3046 # correctly rounded result: repeatedly increase precision
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3047 # until result is unambiguously roundable
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3048 places = p-self._log10_exp_bound()+2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3049 while True:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3050 coeff = _dlog10(c, e, places)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3051 # assert len(str(abs(coeff)))-p >= 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3052 if coeff % (5*10**(len(str(abs(coeff)))-p-1)):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3053 break
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3054 places += 3
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3055 ans = _dec_from_triple(int(coeff<0), str(abs(coeff)), -places)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3056
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3057 context = context._shallow_copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3058 rounding = context._set_rounding(ROUND_HALF_EVEN)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3059 ans = ans._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3060 context.rounding = rounding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3061 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3062
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3063 def logb(self, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3064 """ Returns the exponent of the magnitude of self's MSD.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3065
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3066 The result is the integer which is the exponent of the magnitude
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3067 of the most significant digit of self (as though it were truncated
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3068 to a single digit while maintaining the value of that digit and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3069 without limiting the resulting exponent).
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3070 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3071 # logb(NaN) = NaN
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3072 ans = self._check_nans(context=context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3073 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3074 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3075
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3076 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3077 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3078
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3079 # logb(+/-Inf) = +Inf
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3080 if self._isinfinity():
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
3081 return _Infinity
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3082
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3083 # logb(0) = -Inf, DivisionByZero
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3084 if not self:
43391
b9236a75a6e5 Speed up of the various division operations (remainder, divide,
Facundo Batista <facundobatista@gmail.com>
parents: 43383
diff changeset
3085 return context._raise_error(DivisionByZero, 'logb(0)', 1)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3086
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3087 # otherwise, simply return the adjusted exponent of self, as a
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3088 # Decimal. Note that no attempt is made to fit the result
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3089 # into the current context.
56836
bd776e01993a Merged revisions 75275 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55886
diff changeset
3090 ans = Decimal(self.adjusted())
bd776e01993a Merged revisions 75275 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55886
diff changeset
3091 return ans._fix(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3092
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3093 def _islogical(self):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3094 """Return True if self is a logical operand.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3095
44701
2f11f7d9bdc8 Docstring typos
Andrew M. Kuchling <amk@amk.ca>
parents: 44650
diff changeset
3096 For being logical, it must be a finite number with a sign of 0,
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3097 an exponent of 0, and a coefficient whose digits must all be
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3098 either 0 or 1.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3099 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3100 if self._sign != 0 or self._exp != 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3101 return False
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3102 for dig in self._int:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3103 if dig not in '01':
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3104 return False
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3105 return True
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3106
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3107 def _fill_logical(self, context, opa, opb):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3108 dif = context.prec - len(opa)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3109 if dif > 0:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3110 opa = '0'*dif + opa
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3111 elif dif < 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3112 opa = opa[-context.prec:]
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3113 dif = context.prec - len(opb)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3114 if dif > 0:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3115 opb = '0'*dif + opb
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3116 elif dif < 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3117 opb = opb[-context.prec:]
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3118 return opa, opb
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3119
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3120 def logical_and(self, other, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3121 """Applies an 'and' operation between self and other's digits."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3122 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3123 context = getcontext()
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3124
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3125 other = _convert_other(other, raiseit=True)
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3126
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3127 if not self._islogical() or not other._islogical():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3128 return context._raise_error(InvalidOperation)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3129
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3130 # fill to context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3131 (opa, opb) = self._fill_logical(context, self._int, other._int)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3132
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3133 # make the operation, and clean starting zeroes
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3134 result = "".join([str(int(a)&int(b)) for a,b in zip(opa,opb)])
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3135 return _dec_from_triple(0, result.lstrip('0') or '0', 0)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3136
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3137 def logical_invert(self, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3138 """Invert all its digits."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3139 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3140 context = getcontext()
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3141 return self.logical_xor(_dec_from_triple(0,'1'*context.prec,0),
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3142 context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3143
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3144 def logical_or(self, other, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3145 """Applies an 'or' operation between self and other's digits."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3146 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3147 context = getcontext()
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3148
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3149 other = _convert_other(other, raiseit=True)
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3150
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3151 if not self._islogical() or not other._islogical():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3152 return context._raise_error(InvalidOperation)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3153
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3154 # fill to context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3155 (opa, opb) = self._fill_logical(context, self._int, other._int)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3156
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3157 # make the operation, and clean starting zeroes
50601
2be490abf333 Merged revisions 68317-68318 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50480
diff changeset
3158 result = "".join([str(int(a)|int(b)) for a,b in zip(opa,opb)])
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3159 return _dec_from_triple(0, result.lstrip('0') or '0', 0)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3160
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3161 def logical_xor(self, other, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3162 """Applies an 'xor' operation between self and other's digits."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3163 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3164 context = getcontext()
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3165
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3166 other = _convert_other(other, raiseit=True)
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3167
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3168 if not self._islogical() or not other._islogical():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3169 return context._raise_error(InvalidOperation)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3170
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3171 # fill to context.prec
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3172 (opa, opb) = self._fill_logical(context, self._int, other._int)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3173
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3174 # make the operation, and clean starting zeroes
50601
2be490abf333 Merged revisions 68317-68318 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50480
diff changeset
3175 result = "".join([str(int(a)^int(b)) for a,b in zip(opa,opb)])
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3176 return _dec_from_triple(0, result.lstrip('0') or '0', 0)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3177
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3178 def max_mag(self, other, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3179 """Compares the values numerically with their sign ignored."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3180 other = _convert_other(other, raiseit=True)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3181
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3182 if context is None:
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3183 context = getcontext()
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3184
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3185 if self._is_special or other._is_special:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3186 # If one operand is a quiet NaN and the other is number, then the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3187 # number is always returned
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3188 sn = self._isnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3189 on = other._isnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3190 if sn or on:
50116
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
3191 if on == 1 and sn == 0:
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
3192 return self._fix(context)
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
3193 if sn == 1 and on == 0:
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
3194 return other._fix(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3195 return self._check_nans(other, context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3196
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
3197 c = self.copy_abs()._cmp(other.copy_abs())
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3198 if c == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3199 c = self.compare_total(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3200
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3201 if c == -1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3202 ans = other
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3203 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3204 ans = self
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3205
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
3206 return ans._fix(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3207
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3208 def min_mag(self, other, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3209 """Compares the values numerically with their sign ignored."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3210 other = _convert_other(other, raiseit=True)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3211
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3212 if context is None:
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3213 context = getcontext()
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3214
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3215 if self._is_special or other._is_special:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3216 # If one operand is a quiet NaN and the other is number, then the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3217 # number is always returned
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3218 sn = self._isnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3219 on = other._isnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3220 if sn or on:
50116
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
3221 if on == 1 and sn == 0:
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
3222 return self._fix(context)
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
3223 if sn == 1 and on == 0:
01c023d9218e Merged revisions 67694 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 48847
diff changeset
3224 return other._fix(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3225 return self._check_nans(other, context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3226
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
3227 c = self.copy_abs()._cmp(other.copy_abs())
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3228 if c == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3229 c = self.compare_total(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3230
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3231 if c == -1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3232 ans = self
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3233 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3234 ans = other
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3235
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
3236 return ans._fix(context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3237
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3238 def next_minus(self, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3239 """Returns the largest representable number smaller than itself."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3240 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3241 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3242
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3243 ans = self._check_nans(context=context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3244 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3245 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3246
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3247 if self._isinfinity() == -1:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
3248 return _NegativeInfinity
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3249 if self._isinfinity() == 1:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3250 return _dec_from_triple(0, '9'*context.prec, context.Etop())
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3251
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3252 context = context.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3253 context._set_rounding(ROUND_FLOOR)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3254 context._ignore_all_flags()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3255 new_self = self._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3256 if new_self != self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3257 return new_self
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3258 return self.__sub__(_dec_from_triple(0, '1', context.Etiny()-1),
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3259 context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3260
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3261 def next_plus(self, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3262 """Returns the smallest representable number larger than itself."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3263 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3264 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3265
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3266 ans = self._check_nans(context=context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3267 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3268 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3269
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3270 if self._isinfinity() == 1:
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
3271 return _Infinity
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3272 if self._isinfinity() == -1:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3273 return _dec_from_triple(1, '9'*context.prec, context.Etop())
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3274
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3275 context = context.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3276 context._set_rounding(ROUND_CEILING)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3277 context._ignore_all_flags()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3278 new_self = self._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3279 if new_self != self:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3280 return new_self
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3281 return self.__add__(_dec_from_triple(0, '1', context.Etiny()-1),
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3282 context)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3283
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3284 def next_toward(self, other, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3285 """Returns the number closest to self, in the direction towards other.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3286
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3287 The result is the closest representable number to self
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3288 (excluding self) that is in the direction towards other,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3289 unless both have the same value. If the two operands are
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3290 numerically equal, then the result is a copy of self with the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3291 sign set to be the same as the sign of other.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3292 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3293 other = _convert_other(other, raiseit=True)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3294
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3295 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3296 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3297
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3298 ans = self._check_nans(other, context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3299 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3300 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3301
45201
f55a4f119141 Issue 1979: Make Decimal comparisons (other than !=, ==) involving NaN
Mark Dickinson <dickinsm@gmail.com>
parents: 44923
diff changeset
3302 comparison = self._cmp(other)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3303 if comparison == 0:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3304 return self.copy_sign(other)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3305
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3306 if comparison == -1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3307 ans = self.next_plus(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3308 else: # comparison == 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3309 ans = self.next_minus(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3310
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3311 # decide which flags to raise using value of ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3312 if ans._isinfinity():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3313 context._raise_error(Overflow,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3314 'Infinite result from next_toward',
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3315 ans._sign)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3316 context._raise_error(Rounded)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3317 context._raise_error(Inexact)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3318 elif ans.adjusted() < context.Emin:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3319 context._raise_error(Underflow)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3320 context._raise_error(Subnormal)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3321 context._raise_error(Rounded)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3322 context._raise_error(Inexact)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3323 # if precision == 1 then we don't raise Clamped for a
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3324 # result 0E-Etiny.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3325 if not ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3326 context._raise_error(Clamped)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3327
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3328 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3329
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3330 def number_class(self, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3331 """Returns an indication of the class of self.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3332
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3333 The class is one of the following strings:
44352
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
3334 sNaN
f7bc79112bcf Some minor cleanups. Thanks Mark Dickinson.
Facundo Batista <facundobatista@gmail.com>
parents: 44328
diff changeset
3335 NaN
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3336 -Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3337 -Normal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3338 -Subnormal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3339 -Zero
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3340 +Zero
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3341 +Subnormal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3342 +Normal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3343 +Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3344 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3345 if self.is_snan():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3346 return "sNaN"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3347 if self.is_qnan():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3348 return "NaN"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3349 inf = self._isinfinity()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3350 if inf == 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3351 return "+Infinity"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3352 if inf == -1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3353 return "-Infinity"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3354 if self.is_zero():
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3355 if self._sign:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3356 return "-Zero"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3357 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3358 return "+Zero"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3359 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3360 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3361 if self.is_subnormal(context=context):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3362 if self._sign:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3363 return "-Subnormal"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3364 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3365 return "+Subnormal"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3366 # just a normal, regular, boring number, :)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3367 if self._sign:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3368 return "-Normal"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3369 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3370 return "+Normal"
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3371
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3372 def radix(self):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3373 """Just returns 10, as this is Decimal, :)"""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3374 return Decimal(10)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3375
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3376 def rotate(self, other, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3377 """Returns a rotated copy of self, value-of-other times."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3378 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3379 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3380
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3381 other = _convert_other(other, raiseit=True)
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3382
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3383 ans = self._check_nans(other, context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3384 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3385 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3386
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3387 if other._exp != 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3388 return context._raise_error(InvalidOperation)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3389 if not (-context.prec <= int(other) <= context.prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3390 return context._raise_error(InvalidOperation)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3391
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3392 if self._isinfinity():
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3393 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3394
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3395 # get values, pad if necessary
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3396 torot = int(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3397 rotdig = self._int
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3398 topad = context.prec - len(rotdig)
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3399 if topad > 0:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3400 rotdig = '0'*topad + rotdig
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3401 elif topad < 0:
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3402 rotdig = rotdig[-topad:]
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3403
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3404 # let's rotate!
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3405 rotated = rotdig[torot:] + rotdig[:torot]
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3406 return _dec_from_triple(self._sign,
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3407 rotated.lstrip('0') or '0', self._exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3408
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3409 def scaleb(self, other, context=None):
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3410 """Returns self operand after adding the second value to its exp."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3411 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3412 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3413
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3414 other = _convert_other(other, raiseit=True)
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3415
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3416 ans = self._check_nans(other, context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3417 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3418 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3419
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3420 if other._exp != 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3421 return context._raise_error(InvalidOperation)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3422 liminf = -2 * (context.Emax + context.prec)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3423 limsup = 2 * (context.Emax + context.prec)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3424 if not (liminf <= int(other) <= limsup):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3425 return context._raise_error(InvalidOperation)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3426
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3427 if self._isinfinity():
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3428 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3429
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3430 d = _dec_from_triple(self._sign, self._int, self._exp + int(other))
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3431 d = d._fix(context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3432 return d
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3433
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3434 def shift(self, other, context=None):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3435 """Returns a shifted copy of self, value-of-other times."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3436 if context is None:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3437 context = getcontext()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3438
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3439 other = _convert_other(other, raiseit=True)
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3440
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3441 ans = self._check_nans(other, context)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3442 if ans:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3443 return ans
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3444
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3445 if other._exp != 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3446 return context._raise_error(InvalidOperation)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3447 if not (-context.prec <= int(other) <= context.prec):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3448 return context._raise_error(InvalidOperation)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3449
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3450 if self._isinfinity():
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3451 return Decimal(self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3452
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3453 # get values, pad if necessary
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3454 torot = int(other)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3455 rotdig = self._int
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3456 topad = context.prec - len(rotdig)
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3457 if topad > 0:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3458 rotdig = '0'*topad + rotdig
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3459 elif topad < 0:
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3460 rotdig = rotdig[-topad:]
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3461
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3462 # let's shift!
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3463 if torot < 0:
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3464 shifted = rotdig[:torot]
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3465 else:
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3466 shifted = rotdig + '0'*torot
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3467 shifted = shifted[-context.prec:]
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3468
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3469 return _dec_from_triple(self._sign,
56971
53e38005d507 Merged revisions 75943-75945 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56854
diff changeset
3470 shifted.lstrip('0') or '0', self._exp)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3471
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3472 # Support for pickling, copy, and deepcopy
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3473 def __reduce__(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3474 return (self.__class__, (str(self),))
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3475
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3476 def __copy__(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3477 if type(self) == Decimal:
39120
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
3478 return self # I'm immutable; therefore I am my own clone
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3479 return self.__class__(str(self))
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3480
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3481 def __deepcopy__(self, memo):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3482 if type(self) == Decimal:
39120
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
3483 return self # My components are also immutable
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3484 return self.__class__(str(self))
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3485
45566
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3486 # PEP 3101 support. See also _parse_format_specifier and _format_align
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3487 def __format__(self, specifier, context=None):
45568
facf01f15b15 Fix docstring typo.
Mark Dickinson <dickinsm@gmail.com>
parents: 45566
diff changeset
3488 """Format a Decimal instance according to the given specifier.
45566
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3489
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3490 The specifier should be a standard format specifier, with the
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3491 form described in PEP 3101. Formatting types 'e', 'E', 'f',
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3492 'F', 'g', 'G', and '%' are supported. If the formatting type
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3493 is omitted it defaults to 'g' or 'G', depending on the value
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3494 of context.capitals.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3495
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3496 At this time the 'n' format specifier type (which is supposed
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3497 to use the current locale) is not supported.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3498 """
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3499
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3500 # Note: PEP 3101 says that if the type is not present then
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3501 # there should be at least one digit after the decimal point.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3502 # We take the liberty of ignoring this requirement for
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3503 # Decimal---it's presumably there to make sure that
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3504 # format(float, '') behaves similarly to str(float).
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3505 if context is None:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3506 context = getcontext()
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3507
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3508 spec = _parse_format_specifier(specifier)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3509
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3510 # special values don't care about the type or precision...
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3511 if self._is_special:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3512 return _format_align(str(self), spec)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3513
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3514 # a type of None defaults to 'g' or 'G', depending on context
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3515 # if type is '%', adjust exponent of self accordingly
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3516 if spec['type'] is None:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3517 spec['type'] = ['g', 'G'][context.capitals]
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3518 elif spec['type'] == '%':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3519 self = _dec_from_triple(self._sign, self._int, self._exp+2)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3520
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3521 # round if necessary, taking rounding mode from the context
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3522 rounding = context.rounding
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3523 precision = spec['precision']
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3524 if precision is not None:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3525 if spec['type'] in 'eE':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3526 self = self._round(precision+1, rounding)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3527 elif spec['type'] in 'gG':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3528 if len(self._int) > precision:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3529 self = self._round(precision, rounding)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3530 elif spec['type'] in 'fF%':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3531 self = self._rescale(-precision, rounding)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3532 # special case: zeros with a positive exponent can't be
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3533 # represented in fixed point; rescale them to 0e0.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3534 elif not self and self._exp > 0 and spec['type'] in 'fF%':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3535 self = self._rescale(0, rounding)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3536
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3537 # figure out placement of the decimal point
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3538 leftdigits = self._exp + len(self._int)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3539 if spec['type'] in 'fF%':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3540 dotplace = leftdigits
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3541 elif spec['type'] in 'eE':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3542 if not self and precision is not None:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3543 dotplace = 1 - precision
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3544 else:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3545 dotplace = 1
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3546 elif spec['type'] in 'gG':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3547 if self._exp <= 0 and leftdigits > -6:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3548 dotplace = leftdigits
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3549 else:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3550 dotplace = 1
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3551
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3552 # figure out main part of numeric string...
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3553 if dotplace <= 0:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3554 num = '0.' + '0'*(-dotplace) + self._int
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3555 elif dotplace >= len(self._int):
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3556 # make sure we're not padding a '0' with extra zeros on the right
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3557 assert dotplace==len(self._int) or self._int != '0'
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3558 num = self._int + '0'*(dotplace-len(self._int))
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3559 else:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3560 num = self._int[:dotplace] + '.' + self._int[dotplace:]
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3561
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3562 # ...then the trailing exponent, or trailing '%'
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3563 if leftdigits != dotplace or spec['type'] in 'eE':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3564 echar = {'E': 'E', 'e': 'e', 'G': 'E', 'g': 'e'}[spec['type']]
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3565 num = num + "{0}{1:+}".format(echar, leftdigits-dotplace)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3566 elif spec['type'] == '%':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3567 num = num + '%'
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3568
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3569 # add sign
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3570 if self._sign == 1:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3571 num = '-' + num
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3572 return _format_align(num, spec)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3573
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
3574
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3575 def _dec_from_triple(sign, coefficient, exponent, special=False):
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3576 """Create a decimal instance directly, without any validation,
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3577 normalization (e.g. removal of leading zeros) or argument
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3578 conversion.
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3579
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3580 This function is for *internal use only*.
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3581 """
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3582
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3583 self = object.__new__(Decimal)
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3584 self._sign = sign
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3585 self._int = coefficient
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3586 self._exp = exponent
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3587 self._is_special = special
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3588
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3589 return self
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
3590
51294
aea90f5f398b Register decimals as numbers.Number
Raymond Hettinger <python@rcn.com>
parents: 51028
diff changeset
3591 # Register Decimal as a kind of Number (an abstract base class).
aea90f5f398b Register decimals as numbers.Number
Raymond Hettinger <python@rcn.com>
parents: 51028
diff changeset
3592 # However, do not register it as Real (because Decimals are not
aea90f5f398b Register decimals as numbers.Number
Raymond Hettinger <python@rcn.com>
parents: 51028
diff changeset
3593 # interoperable with floats).
aea90f5f398b Register decimals as numbers.Number
Raymond Hettinger <python@rcn.com>
parents: 51028
diff changeset
3594 _numbers.Number.register(Decimal)
aea90f5f398b Register decimals as numbers.Number
Raymond Hettinger <python@rcn.com>
parents: 51028
diff changeset
3595
aea90f5f398b Register decimals as numbers.Number
Raymond Hettinger <python@rcn.com>
parents: 51028
diff changeset
3596
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3597 ##### Context class #######################################################
39120
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
3598
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
3599
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
3600 # get rounding method function:
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3601 rounding_functions = [name for name in Decimal.__dict__.keys()
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3602 if name.startswith('_round_')]
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3603 for name in rounding_functions:
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3604 # name is like _round_half_even, goes to the global ROUND_HALF_EVEN value.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3605 globalname = name[1:].upper()
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3606 val = globals()[globalname]
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3607 Decimal._pick_rounding_function[val] = name
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3608
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3609 del name, val, globalname, rounding_functions
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3610
39721
2f086d58ca10 Make decimal.ContextManager a private implementation detail of decimal.localcontext()
Nick Coghlan <ncoghlan@gmail.com>
parents: 39707
diff changeset
3611 class _ContextManager(object):
39707
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
3612 """Context manager class to support localcontext().
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
3613
39721
2f086d58ca10 Make decimal.ContextManager a private implementation detail of decimal.localcontext()
Nick Coghlan <ncoghlan@gmail.com>
parents: 39707
diff changeset
3614 Sets a copy of the supplied context in __enter__() and restores
39707
a83957c91fdb Fix the wrongheaded implementation of context management in the decimal module and add unit tests. (python-dev discussion is ongoing regarding what we do about Python 2.5)
Nick Coghlan <ncoghlan@gmail.com>
parents: 39120
diff changeset
3615 the previous decimal context in __exit__()
36737
fa92fe15251a Updates to the with-statement:
Guido van Rossum <guido@python.org>
parents: 35379
diff changeset
3616 """
fa92fe15251a Updates to the with-statement:
Guido van Rossum <guido@python.org>
parents: 35379
diff changeset
3617 def __init__(self, new_context):
39721
2f086d58ca10 Make decimal.ContextManager a private implementation detail of decimal.localcontext()
Nick Coghlan <ncoghlan@gmail.com>
parents: 39707
diff changeset
3618 self.new_context = new_context.copy()
36737
fa92fe15251a Updates to the with-statement:
Guido van Rossum <guido@python.org>
parents: 35379
diff changeset
3619 def __enter__(self):
fa92fe15251a Updates to the with-statement:
Guido van Rossum <guido@python.org>
parents: 35379
diff changeset
3620 self.saved_context = getcontext()
fa92fe15251a Updates to the with-statement:
Guido van Rossum <guido@python.org>
parents: 35379
diff changeset
3621 setcontext(self.new_context)
fa92fe15251a Updates to the with-statement:
Guido van Rossum <guido@python.org>
parents: 35379
diff changeset
3622 return self.new_context
fa92fe15251a Updates to the with-statement:
Guido van Rossum <guido@python.org>
parents: 35379
diff changeset
3623 def __exit__(self, t, v, tb):
fa92fe15251a Updates to the with-statement:
Guido van Rossum <guido@python.org>
parents: 35379
diff changeset
3624 setcontext(self.saved_context)
fa92fe15251a Updates to the with-statement:
Guido van Rossum <guido@python.org>
parents: 35379
diff changeset
3625
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3626 class Context(object):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3627 """Contains the context for a Decimal instance.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3628
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3629 Contains:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3630 prec - precision (for use in rounding, division, square roots..)
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3631 rounding - rounding type (how you round)
32576
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
3632 traps - If traps[exception] = 1, then the exception is
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3633 raised when it is caused. Otherwise, a value is
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3634 substituted in.
46643
ec09ad5bed1a Backport Raymond's changes in r60508 to Python 2.6.
Mark Dickinson <dickinsm@gmail.com>
parents: 46625
diff changeset
3635 flags - When an exception is caused, flags[exception] is set.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3636 (Whether or not the trap_enabler is set)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3637 Should be reset by user of Decimal instance.
32489
ab0a2b74ddfd Changed the rounding constant values to match their variable names.
Raymond Hettinger <python@rcn.com>
parents: 32487
diff changeset
3638 Emin - Minimum exponent
ab0a2b74ddfd Changed the rounding constant values to match their variable names.
Raymond Hettinger <python@rcn.com>
parents: 32487
diff changeset
3639 Emax - Maximum exponent
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3640 capitals - If 1, 1*10^1 is printed as 1E+1.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3641 If 0, printed as 1e1
32496
9c87518faf6b * Fixup docstrings
Raymond Hettinger <python@rcn.com>
parents: 32489
diff changeset
3642 _clamp - If 1, change exponents if too high (Default 0)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3643 """
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3644
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3645 def __init__(self, prec=None, rounding=None,
33722
74a57e6684f3 Don't use mutable values for method defaults.
Raymond Hettinger <python@rcn.com>
parents: 33695
diff changeset
3646 traps=None, flags=None,
32489
ab0a2b74ddfd Changed the rounding constant values to match their variable names.
Raymond Hettinger <python@rcn.com>
parents: 32487
diff changeset
3647 Emin=None, Emax=None,
32496
9c87518faf6b * Fixup docstrings
Raymond Hettinger <python@rcn.com>
parents: 32489
diff changeset
3648 capitals=None, _clamp=0,
33722
74a57e6684f3 Don't use mutable values for method defaults.
Raymond Hettinger <python@rcn.com>
parents: 33695
diff changeset
3649 _ignored_flags=None):
74a57e6684f3 Don't use mutable values for method defaults.
Raymond Hettinger <python@rcn.com>
parents: 33695
diff changeset
3650 if flags is None:
74a57e6684f3 Don't use mutable values for method defaults.
Raymond Hettinger <python@rcn.com>
parents: 33695
diff changeset
3651 flags = []
74a57e6684f3 Don't use mutable values for method defaults.
Raymond Hettinger <python@rcn.com>
parents: 33695
diff changeset
3652 if _ignored_flags is None:
74a57e6684f3 Don't use mutable values for method defaults.
Raymond Hettinger <python@rcn.com>
parents: 33695
diff changeset
3653 _ignored_flags = []
32576
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
3654 if not isinstance(flags, dict):
46653
1872e1dc035f Make sure that Context traps and flags dictionaries have values 0 and 1
Mark Dickinson <dickinsm@gmail.com>
parents: 46651
diff changeset
3655 flags = dict([(s, int(s in flags)) for s in _signals])
32667
941c239cb6d2 * Hide a loop induction variable that was inadvertantly being picked up
Raymond Hettinger <python@rcn.com>
parents: 32666
diff changeset
3656 del s
32576
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
3657 if traps is not None and not isinstance(traps, dict):
46653
1872e1dc035f Make sure that Context traps and flags dictionaries have values 0 and 1
Mark Dickinson <dickinsm@gmail.com>
parents: 46651
diff changeset
3658 traps = dict([(s, int(s in traps)) for s in _signals])
32667
941c239cb6d2 * Hide a loop induction variable that was inadvertantly being picked up
Raymond Hettinger <python@rcn.com>
parents: 32666
diff changeset
3659 del s
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3660 for name, val in locals().items():
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3661 if val is None:
35035
c55899863b9c Minor namespace clean-up.
Raymond Hettinger <python@rcn.com>
parents: 34812
diff changeset
3662 setattr(self, name, _copy.copy(getattr(DefaultContext, name)))
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3663 else:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3664 setattr(self, name, val)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3665 del self.self
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3666
32487
fa23a9b18967 Fix clear_flags(). Make a readable (not evalable) Context repr.
Raymond Hettinger <python@rcn.com>
parents: 32482
diff changeset
3667 def __repr__(self):
32576
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
3668 """Show the current context."""
32487
fa23a9b18967 Fix clear_flags(). Make a readable (not evalable) Context repr.
Raymond Hettinger <python@rcn.com>
parents: 32482
diff changeset
3669 s = []
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3670 s.append('Context(prec=%(prec)d, rounding=%(rounding)s, '
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3671 'Emin=%(Emin)d, Emax=%(Emax)d, capitals=%(capitals)d'
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3672 % vars(self))
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3673 names = [f.__name__ for f, v in self.flags.items() if v]
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3674 s.append('flags=[' + ', '.join(names) + ']')
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3675 names = [t.__name__ for t, v in self.traps.items() if v]
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3676 s.append('traps=[' + ', '.join(names) + ']')
32487
fa23a9b18967 Fix clear_flags(). Make a readable (not evalable) Context repr.
Raymond Hettinger <python@rcn.com>
parents: 32482
diff changeset
3677 return ', '.join(s) + ')'
fa23a9b18967 Fix clear_flags(). Make a readable (not evalable) Context repr.
Raymond Hettinger <python@rcn.com>
parents: 32482
diff changeset
3678
32477
bc586db9945a Work through several open todos:
Raymond Hettinger <python@rcn.com>
parents: 32456
diff changeset
3679 def clear_flags(self):
bc586db9945a Work through several open todos:
Raymond Hettinger <python@rcn.com>
parents: 32456
diff changeset
3680 """Reset all flags to zero"""
bc586db9945a Work through several open todos:
Raymond Hettinger <python@rcn.com>
parents: 32456
diff changeset
3681 for flag in self.flags:
32487
fa23a9b18967 Fix clear_flags(). Make a readable (not evalable) Context repr.
Raymond Hettinger <python@rcn.com>
parents: 32482
diff changeset
3682 self.flags[flag] = 0
32477
bc586db9945a Work through several open todos:
Raymond Hettinger <python@rcn.com>
parents: 32456
diff changeset
3683
33044
2749334d71a4 * Context.copy() now makes a deepcopy.
Raymond Hettinger <python@rcn.com>
parents: 32980
diff changeset
3684 def _shallow_copy(self):
2749334d71a4 * Context.copy() now makes a deepcopy.
Raymond Hettinger <python@rcn.com>
parents: 32980
diff changeset
3685 """Returns a shallow copy from self."""
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
3686 nc = Context(self.prec, self.rounding, self.traps,
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
3687 self.flags, self.Emin, self.Emax,
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
3688 self.capitals, self._clamp, self._ignored_flags)
33044
2749334d71a4 * Context.copy() now makes a deepcopy.
Raymond Hettinger <python@rcn.com>
parents: 32980
diff changeset
3689 return nc
2749334d71a4 * Context.copy() now makes a deepcopy.
Raymond Hettinger <python@rcn.com>
parents: 32980
diff changeset
3690
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3691 def copy(self):
33044
2749334d71a4 * Context.copy() now makes a deepcopy.
Raymond Hettinger <python@rcn.com>
parents: 32980
diff changeset
3692 """Returns a deep copy from self."""
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3693 nc = Context(self.prec, self.rounding, self.traps.copy(),
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
3694 self.flags.copy(), self.Emin, self.Emax,
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
3695 self.capitals, self._clamp, self._ignored_flags)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3696 return nc
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3697 __copy__ = copy
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3698
32560
e4b96c3a3e12 Module and tests:
Raymond Hettinger <python@rcn.com>
parents: 32529
diff changeset
3699 def _raise_error(self, condition, explanation = None, *args):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3700 """Handles an error
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3701
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3702 If the flag is in _ignored_flags, returns the default response.
46643
ec09ad5bed1a Backport Raymond's changes in r60508 to Python 2.6.
Mark Dickinson <dickinsm@gmail.com>
parents: 46625
diff changeset
3703 Otherwise, it sets the flag, then, if the corresponding
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3704 trap_enabler is set, it reaises the exception. Otherwise, it returns
46643
ec09ad5bed1a Backport Raymond's changes in r60508 to Python 2.6.
Mark Dickinson <dickinsm@gmail.com>
parents: 46625
diff changeset
3705 the default value after setting the flag.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3706 """
32560
e4b96c3a3e12 Module and tests:
Raymond Hettinger <python@rcn.com>
parents: 32529
diff changeset
3707 error = _condition_map.get(condition, condition)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3708 if error in self._ignored_flags:
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3709 # Don't touch the flag
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3710 return error().handle(self, *args)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3711
46643
ec09ad5bed1a Backport Raymond's changes in r60508 to Python 2.6.
Mark Dickinson <dickinsm@gmail.com>
parents: 46625
diff changeset
3712 self.flags[error] = 1
32576
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
3713 if not self.traps[error]:
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3714 # The errors define how to handle themselves.
32560
e4b96c3a3e12 Module and tests:
Raymond Hettinger <python@rcn.com>
parents: 32529
diff changeset
3715 return condition().handle(self, *args)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3716
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3717 # Errors should only be risked on copies of the context
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3718 # self._ignored_flags = []
46651
c97e36abcdd5 Some very minor changes to decimal.py in Python 2.6, aimed
Mark Dickinson <dickinsm@gmail.com>
parents: 46643
diff changeset
3719 raise error(explanation)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3720
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3721 def _ignore_all_flags(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3722 """Ignore all flags, if they are raised"""
32666
c13d911ae05b * Rename "Signals" to "_signals" making it non-public.
Raymond Hettinger <python@rcn.com>
parents: 32576
diff changeset
3723 return self._ignore_flags(*_signals)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3724
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3725 def _ignore_flags(self, *flags):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3726 """Ignore the flags, if they are raised"""
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3727 # Do not mutate-- This way, copies of a context leave the original
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3728 # alone.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3729 self._ignored_flags = (self._ignored_flags + list(flags))
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3730 return list(flags)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3731
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3732 def _regard_flags(self, *flags):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3733 """Stop ignoring the flags, if they are raised"""
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3734 if flags and isinstance(flags[0], (tuple,list)):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3735 flags = flags[0]
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3736 for flag in flags:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3737 self._ignored_flags.remove(flag)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3738
47961
f9b80a820a25 Issue 2235: __hash__ is once again inherited by default, but inheritance can be blocked explicitly so that collections.Hashable remains meaningful
Nick Coghlan <ncoghlan@gmail.com>
parents: 47872
diff changeset
3739 # We inherit object.__hash__, so we must deny this explicitly
f9b80a820a25 Issue 2235: __hash__ is once again inherited by default, but inheritance can be blocked explicitly so that collections.Hashable remains meaningful
Nick Coghlan <ncoghlan@gmail.com>
parents: 47872
diff changeset
3740 __hash__ = None
32560
e4b96c3a3e12 Module and tests:
Raymond Hettinger <python@rcn.com>
parents: 32529
diff changeset
3741
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3742 def Etiny(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3743 """Returns Etiny (= Emin - prec + 1)"""
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3744 return int(self.Emin - self.prec + 1)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3745
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3746 def Etop(self):
32496
9c87518faf6b * Fixup docstrings
Raymond Hettinger <python@rcn.com>
parents: 32489
diff changeset
3747 """Returns maximum exponent (= Emax - prec + 1)"""
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3748 return int(self.Emax - self.prec + 1)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3749
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3750 def _set_rounding(self, type):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3751 """Sets the rounding type.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3752
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3753 Sets the rounding type, and returns the current (previous)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3754 rounding type. Often used like:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3755
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3756 context = context.copy()
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3757 # so you don't change the calling context
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3758 # if an error occurs in the middle.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3759 rounding = context._set_rounding(ROUND_UP)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3760 val = self.__sub__(other, context=context)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3761 context._set_rounding(rounding)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3762
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3763 This will make it round up for that operation.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3764 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3765 rounding = self.rounding
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3766 self.rounding= type
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3767 return rounding
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3768
32666
c13d911ae05b * Rename "Signals" to "_signals" making it non-public.
Raymond Hettinger <python@rcn.com>
parents: 32576
diff changeset
3769 def create_decimal(self, num='0'):
44650
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3770 """Creates a new Decimal instance but using self as context.
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3771
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3772 This method implements the to-number operation of the
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3773 IBM Decimal specification."""
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3774
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3775 if isinstance(num, basestring) and num != num.strip():
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3776 return self._raise_error(ConversionSyntax,
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3777 "no trailing or leading whitespace is "
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3778 "permitted.")
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
3779
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3780 d = Decimal(num, context=self)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3781 if d._isnan() and len(d._int) > self.prec - self._clamp:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3782 return self._raise_error(ConversionSyntax,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3783 "diagnostic info too long in NaN")
33695
924bb2aad4f4 SF patch #1043218
Raymond Hettinger <python@rcn.com>
parents: 33596
diff changeset
3784 return d._fix(self)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3785
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3786 # Methods
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3787 def abs(self, a):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3788 """Returns the absolute value of the operand.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3789
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3790 If the operand is negative, the result is the same as using the minus
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
3791 operation on the operand. Otherwise, the result is the same as using
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3792 the plus operation on the operand.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3793
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3794 >>> ExtendedContext.abs(Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3795 Decimal('2.1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3796 >>> ExtendedContext.abs(Decimal('-100'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3797 Decimal('100')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3798 >>> ExtendedContext.abs(Decimal('101.5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3799 Decimal('101.5')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3800 >>> ExtendedContext.abs(Decimal('-101.5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3801 Decimal('101.5')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3802 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3803 return a.__abs__(context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3804
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3805 def add(self, a, b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3806 """Return the sum of the two operands.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3807
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3808 >>> ExtendedContext.add(Decimal('12'), Decimal('7.00'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3809 Decimal('19.00')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3810 >>> ExtendedContext.add(Decimal('1E+2'), Decimal('1.01E+4'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3811 Decimal('1.02E+4')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3812 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3813 return a.__add__(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3814
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3815 def _apply(self, a):
33695
924bb2aad4f4 SF patch #1043218
Raymond Hettinger <python@rcn.com>
parents: 33596
diff changeset
3816 return str(a._fix(self))
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3817
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3818 def canonical(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3819 """Returns the same Decimal object.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3820
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3821 As we do not have different encodings for the same number, the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3822 received object already is in its canonical form.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3823
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3824 >>> ExtendedContext.canonical(Decimal('2.50'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3825 Decimal('2.50')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3826 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3827 return a.canonical(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3828
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3829 def compare(self, a, b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3830 """Compares values numerically.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3831
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3832 If the signs of the operands differ, a value representing each operand
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3833 ('-1' if the operand is less than zero, '0' if the operand is zero or
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3834 negative zero, or '1' if the operand is greater than zero) is used in
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3835 place of that operand for the comparison instead of the actual
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3836 operand.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3837
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3838 The comparison is then effected by subtracting the second operand from
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3839 the first and then returning a value according to the result of the
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3840 subtraction: '-1' if the result is less than zero, '0' if the result is
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3841 zero or negative zero, or '1' if the result is greater than zero.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3842
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3843 >>> ExtendedContext.compare(Decimal('2.1'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3844 Decimal('-1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3845 >>> ExtendedContext.compare(Decimal('2.1'), Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3846 Decimal('0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3847 >>> ExtendedContext.compare(Decimal('2.1'), Decimal('2.10'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3848 Decimal('0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3849 >>> ExtendedContext.compare(Decimal('3'), Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3850 Decimal('1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3851 >>> ExtendedContext.compare(Decimal('2.1'), Decimal('-3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3852 Decimal('1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3853 >>> ExtendedContext.compare(Decimal('-3'), Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3854 Decimal('-1')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3855 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3856 return a.compare(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3857
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3858 def compare_signal(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3859 """Compares the values of the two operands numerically.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3860
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3861 It's pretty much like compare(), but all NaNs signal, with signaling
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3862 NaNs taking precedence over quiet NaNs.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3863
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3864 >>> c = ExtendedContext
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3865 >>> c.compare_signal(Decimal('2.1'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3866 Decimal('-1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3867 >>> c.compare_signal(Decimal('2.1'), Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3868 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3869 >>> c.flags[InvalidOperation] = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3870 >>> print c.flags[InvalidOperation]
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3871 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3872 >>> c.compare_signal(Decimal('NaN'), Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3873 Decimal('NaN')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3874 >>> print c.flags[InvalidOperation]
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3875 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3876 >>> c.flags[InvalidOperation] = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3877 >>> print c.flags[InvalidOperation]
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3878 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3879 >>> c.compare_signal(Decimal('sNaN'), Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3880 Decimal('NaN')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3881 >>> print c.flags[InvalidOperation]
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3882 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3883 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3884 return a.compare_signal(b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3885
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3886 def compare_total(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3887 """Compares two operands using their abstract representation.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3888
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3889 This is not like the standard compare, which use their numerical
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3890 value. Note that a total ordering is defined for all possible abstract
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3891 representations.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3892
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3893 >>> ExtendedContext.compare_total(Decimal('12.73'), Decimal('127.9'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3894 Decimal('-1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3895 >>> ExtendedContext.compare_total(Decimal('-127'), Decimal('12'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3896 Decimal('-1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3897 >>> ExtendedContext.compare_total(Decimal('12.30'), Decimal('12.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3898 Decimal('-1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3899 >>> ExtendedContext.compare_total(Decimal('12.30'), Decimal('12.30'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3900 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3901 >>> ExtendedContext.compare_total(Decimal('12.3'), Decimal('12.300'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3902 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3903 >>> ExtendedContext.compare_total(Decimal('12.3'), Decimal('NaN'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3904 Decimal('-1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3905 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3906 return a.compare_total(b)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3907
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3908 def compare_total_mag(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3909 """Compares two operands using their abstract representation ignoring sign.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3910
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3911 Like compare_total, but with operand's sign ignored and assumed to be 0.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3912 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3913 return a.compare_total_mag(b)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3914
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3915 def copy_abs(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3916 """Returns a copy of the operand with the sign set to 0.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3917
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3918 >>> ExtendedContext.copy_abs(Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3919 Decimal('2.1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3920 >>> ExtendedContext.copy_abs(Decimal('-100'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3921 Decimal('100')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3922 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3923 return a.copy_abs()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3924
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3925 def copy_decimal(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3926 """Returns a copy of the decimal objet.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3927
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3928 >>> ExtendedContext.copy_decimal(Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3929 Decimal('2.1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3930 >>> ExtendedContext.copy_decimal(Decimal('-1.00'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3931 Decimal('-1.00')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3932 """
43383
8890be9386b7 The methods always return Decimal classes, even if they're
Facundo Batista <facundobatista@gmail.com>
parents: 43362
diff changeset
3933 return Decimal(a)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3934
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3935 def copy_negate(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3936 """Returns a copy of the operand with the sign inverted.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3937
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3938 >>> ExtendedContext.copy_negate(Decimal('101.5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3939 Decimal('-101.5')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3940 >>> ExtendedContext.copy_negate(Decimal('-101.5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3941 Decimal('101.5')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3942 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3943 return a.copy_negate()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3944
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3945 def copy_sign(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3946 """Copies the second operand's sign to the first one.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3947
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3948 In detail, it returns a copy of the first operand with the sign
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3949 equal to the sign of the second operand.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3950
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3951 >>> ExtendedContext.copy_sign(Decimal( '1.50'), Decimal('7.33'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3952 Decimal('1.50')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3953 >>> ExtendedContext.copy_sign(Decimal('-1.50'), Decimal('7.33'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3954 Decimal('1.50')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3955 >>> ExtendedContext.copy_sign(Decimal( '1.50'), Decimal('-7.33'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3956 Decimal('-1.50')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3957 >>> ExtendedContext.copy_sign(Decimal('-1.50'), Decimal('-7.33'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3958 Decimal('-1.50')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3959 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3960 return a.copy_sign(b)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
3961
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3962 def divide(self, a, b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3963 """Decimal division in a specified context.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3964
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3965 >>> ExtendedContext.divide(Decimal('1'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3966 Decimal('0.333333333')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3967 >>> ExtendedContext.divide(Decimal('2'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3968 Decimal('0.666666667')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3969 >>> ExtendedContext.divide(Decimal('5'), Decimal('2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3970 Decimal('2.5')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3971 >>> ExtendedContext.divide(Decimal('1'), Decimal('10'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3972 Decimal('0.1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3973 >>> ExtendedContext.divide(Decimal('12'), Decimal('12'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3974 Decimal('1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3975 >>> ExtendedContext.divide(Decimal('8.00'), Decimal('2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3976 Decimal('4.00')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3977 >>> ExtendedContext.divide(Decimal('2.400'), Decimal('2.0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3978 Decimal('1.20')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3979 >>> ExtendedContext.divide(Decimal('1000'), Decimal('100'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3980 Decimal('10')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3981 >>> ExtendedContext.divide(Decimal('1000'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3982 Decimal('1000')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3983 >>> ExtendedContext.divide(Decimal('2.40E+6'), Decimal('2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3984 Decimal('1.20E+6')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3985 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3986 return a.__div__(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3987
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3988 def divide_int(self, a, b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3989 """Divides two numbers and returns the integer part of the result.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3990
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3991 >>> ExtendedContext.divide_int(Decimal('2'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3992 Decimal('0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3993 >>> ExtendedContext.divide_int(Decimal('10'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3994 Decimal('3')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
3995 >>> ExtendedContext.divide_int(Decimal('1'), Decimal('0.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
3996 Decimal('3')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3997 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3998 return a.__floordiv__(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
3999
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4000 def divmod(self, a, b):
58169
86bf440bf9bf Merged revisions 77324 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56971
diff changeset
4001 """Return (a // b, a % b)
86bf440bf9bf Merged revisions 77324 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56971
diff changeset
4002
86bf440bf9bf Merged revisions 77324 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56971
diff changeset
4003 >>> ExtendedContext.divmod(Decimal(8), Decimal(3))
86bf440bf9bf Merged revisions 77324 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56971
diff changeset
4004 (Decimal('2'), Decimal('2'))
86bf440bf9bf Merged revisions 77324 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56971
diff changeset
4005 >>> ExtendedContext.divmod(Decimal(8), Decimal(4))
86bf440bf9bf Merged revisions 77324 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56971
diff changeset
4006 (Decimal('2'), Decimal('0'))
86bf440bf9bf Merged revisions 77324 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 56971
diff changeset
4007 """
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4008 return a.__divmod__(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4009
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4010 def exp(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4011 """Returns e ** a.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4012
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4013 >>> c = ExtendedContext.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4014 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4015 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4016 >>> c.exp(Decimal('-Infinity'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4017 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4018 >>> c.exp(Decimal('-1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4019 Decimal('0.367879441')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4020 >>> c.exp(Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4021 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4022 >>> c.exp(Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4023 Decimal('2.71828183')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4024 >>> c.exp(Decimal('0.693147181'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4025 Decimal('2.00000000')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4026 >>> c.exp(Decimal('+Infinity'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4027 Decimal('Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4028 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4029 return a.exp(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4030
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4031 def fma(self, a, b, c):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4032 """Returns a multiplied by b, plus c.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4033
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4034 The first two operands are multiplied together, using multiply,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4035 the third operand is then added to the result of that
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4036 multiplication, using add, all with only one final rounding.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4037
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4038 >>> ExtendedContext.fma(Decimal('3'), Decimal('5'), Decimal('7'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4039 Decimal('22')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4040 >>> ExtendedContext.fma(Decimal('3'), Decimal('-5'), Decimal('7'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4041 Decimal('-8')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4042 >>> ExtendedContext.fma(Decimal('888565290'), Decimal('1557.96930'), Decimal('-86087.7578'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4043 Decimal('1.38435736E+12')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4044 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4045 return a.fma(b, c, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4046
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4047 def is_canonical(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4048 """Return True if the operand is canonical; otherwise return False.
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4049
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4050 Currently, the encoding of a Decimal instance is always
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4051 canonical, so this method returns True for any Decimal.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4052
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4053 >>> ExtendedContext.is_canonical(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4054 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4055 """
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4056 return a.is_canonical()
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4057
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4058 def is_finite(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4059 """Return True if the operand is finite; otherwise return False.
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4060
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4061 A Decimal instance is considered finite if it is neither
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4062 infinite nor a NaN.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4063
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4064 >>> ExtendedContext.is_finite(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4065 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4066 >>> ExtendedContext.is_finite(Decimal('-0.3'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4067 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4068 >>> ExtendedContext.is_finite(Decimal('0'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4069 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4070 >>> ExtendedContext.is_finite(Decimal('Inf'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4071 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4072 >>> ExtendedContext.is_finite(Decimal('NaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4073 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4074 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4075 return a.is_finite()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4076
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4077 def is_infinite(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4078 """Return True if the operand is infinite; otherwise return False.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4079
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4080 >>> ExtendedContext.is_infinite(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4081 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4082 >>> ExtendedContext.is_infinite(Decimal('-Inf'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4083 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4084 >>> ExtendedContext.is_infinite(Decimal('NaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4085 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4086 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4087 return a.is_infinite()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4088
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4089 def is_nan(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4090 """Return True if the operand is a qNaN or sNaN;
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4091 otherwise return False.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4092
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4093 >>> ExtendedContext.is_nan(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4094 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4095 >>> ExtendedContext.is_nan(Decimal('NaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4096 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4097 >>> ExtendedContext.is_nan(Decimal('-sNaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4098 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4099 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4100 return a.is_nan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4101
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4102 def is_normal(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4103 """Return True if the operand is a normal number;
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4104 otherwise return False.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4105
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4106 >>> c = ExtendedContext.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4107 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4108 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4109 >>> c.is_normal(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4110 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4111 >>> c.is_normal(Decimal('0.1E-999'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4112 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4113 >>> c.is_normal(Decimal('0.00'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4114 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4115 >>> c.is_normal(Decimal('-Inf'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4116 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4117 >>> c.is_normal(Decimal('NaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4118 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4119 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4120 return a.is_normal(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4121
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4122 def is_qnan(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4123 """Return True if the operand is a quiet NaN; otherwise return False.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4124
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4125 >>> ExtendedContext.is_qnan(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4126 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4127 >>> ExtendedContext.is_qnan(Decimal('NaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4128 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4129 >>> ExtendedContext.is_qnan(Decimal('sNaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4130 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4131 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4132 return a.is_qnan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4133
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4134 def is_signed(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4135 """Return True if the operand is negative; otherwise return False.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4136
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4137 >>> ExtendedContext.is_signed(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4138 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4139 >>> ExtendedContext.is_signed(Decimal('-12'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4140 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4141 >>> ExtendedContext.is_signed(Decimal('-0'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4142 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4143 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4144 return a.is_signed()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4145
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4146 def is_snan(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4147 """Return True if the operand is a signaling NaN;
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4148 otherwise return False.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4149
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4150 >>> ExtendedContext.is_snan(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4151 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4152 >>> ExtendedContext.is_snan(Decimal('NaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4153 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4154 >>> ExtendedContext.is_snan(Decimal('sNaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4155 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4156 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4157 return a.is_snan()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4158
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4159 def is_subnormal(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4160 """Return True if the operand is subnormal; otherwise return False.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4161
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4162 >>> c = ExtendedContext.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4163 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4164 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4165 >>> c.is_subnormal(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4166 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4167 >>> c.is_subnormal(Decimal('0.1E-999'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4168 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4169 >>> c.is_subnormal(Decimal('0.00'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4170 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4171 >>> c.is_subnormal(Decimal('-Inf'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4172 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4173 >>> c.is_subnormal(Decimal('NaN'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4174 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4175 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4176 return a.is_subnormal(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4177
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4178 def is_zero(self, a):
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4179 """Return True if the operand is a zero; otherwise return False.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4180
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4181 >>> ExtendedContext.is_zero(Decimal('0'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4182 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4183 >>> ExtendedContext.is_zero(Decimal('2.50'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4184 False
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4185 >>> ExtendedContext.is_zero(Decimal('-0E+2'))
43454
9d6d9ac95ae1 Made the various is_* operations return booleans. This was discussed
Facundo Batista <facundobatista@gmail.com>
parents: 43409
diff changeset
4186 True
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4187 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4188 return a.is_zero()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4189
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4190 def ln(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4191 """Returns the natural (base e) logarithm of the operand.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4192
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4193 >>> c = ExtendedContext.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4194 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4195 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4196 >>> c.ln(Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4197 Decimal('-Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4198 >>> c.ln(Decimal('1.000'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4199 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4200 >>> c.ln(Decimal('2.71828183'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4201 Decimal('1.00000000')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4202 >>> c.ln(Decimal('10'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4203 Decimal('2.30258509')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4204 >>> c.ln(Decimal('+Infinity'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4205 Decimal('Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4206 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4207 return a.ln(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4208
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4209 def log10(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4210 """Returns the base 10 logarithm of the operand.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4211
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4212 >>> c = ExtendedContext.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4213 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4214 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4215 >>> c.log10(Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4216 Decimal('-Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4217 >>> c.log10(Decimal('0.001'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4218 Decimal('-3')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4219 >>> c.log10(Decimal('1.000'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4220 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4221 >>> c.log10(Decimal('2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4222 Decimal('0.301029996')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4223 >>> c.log10(Decimal('10'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4224 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4225 >>> c.log10(Decimal('70'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4226 Decimal('1.84509804')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4227 >>> c.log10(Decimal('+Infinity'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4228 Decimal('Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4229 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4230 return a.log10(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4231
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4232 def logb(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4233 """ Returns the exponent of the magnitude of the operand's MSD.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4234
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4235 The result is the integer which is the exponent of the magnitude
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4236 of the most significant digit of the operand (as though the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4237 operand were truncated to a single digit while maintaining the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4238 value of that digit and without limiting the resulting exponent).
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4239
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4240 >>> ExtendedContext.logb(Decimal('250'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4241 Decimal('2')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4242 >>> ExtendedContext.logb(Decimal('2.50'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4243 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4244 >>> ExtendedContext.logb(Decimal('0.03'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4245 Decimal('-2')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4246 >>> ExtendedContext.logb(Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4247 Decimal('-Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4248 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4249 return a.logb(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4250
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4251 def logical_and(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4252 """Applies the logical operation 'and' between each operand's digits.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4253
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4254 The operands must be both logical numbers.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4255
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4256 >>> ExtendedContext.logical_and(Decimal('0'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4257 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4258 >>> ExtendedContext.logical_and(Decimal('0'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4259 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4260 >>> ExtendedContext.logical_and(Decimal('1'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4261 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4262 >>> ExtendedContext.logical_and(Decimal('1'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4263 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4264 >>> ExtendedContext.logical_and(Decimal('1100'), Decimal('1010'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4265 Decimal('1000')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4266 >>> ExtendedContext.logical_and(Decimal('1111'), Decimal('10'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4267 Decimal('10')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4268 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4269 return a.logical_and(b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4270
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4271 def logical_invert(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4272 """Invert all the digits in the operand.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4273
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4274 The operand must be a logical number.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4275
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4276 >>> ExtendedContext.logical_invert(Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4277 Decimal('111111111')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4278 >>> ExtendedContext.logical_invert(Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4279 Decimal('111111110')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4280 >>> ExtendedContext.logical_invert(Decimal('111111111'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4281 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4282 >>> ExtendedContext.logical_invert(Decimal('101010101'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4283 Decimal('10101010')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4284 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4285 return a.logical_invert(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4286
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4287 def logical_or(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4288 """Applies the logical operation 'or' between each operand's digits.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4289
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4290 The operands must be both logical numbers.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4291
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4292 >>> ExtendedContext.logical_or(Decimal('0'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4293 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4294 >>> ExtendedContext.logical_or(Decimal('0'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4295 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4296 >>> ExtendedContext.logical_or(Decimal('1'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4297 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4298 >>> ExtendedContext.logical_or(Decimal('1'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4299 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4300 >>> ExtendedContext.logical_or(Decimal('1100'), Decimal('1010'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4301 Decimal('1110')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4302 >>> ExtendedContext.logical_or(Decimal('1110'), Decimal('10'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4303 Decimal('1110')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4304 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4305 return a.logical_or(b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4306
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4307 def logical_xor(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4308 """Applies the logical operation 'xor' between each operand's digits.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4309
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4310 The operands must be both logical numbers.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4311
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4312 >>> ExtendedContext.logical_xor(Decimal('0'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4313 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4314 >>> ExtendedContext.logical_xor(Decimal('0'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4315 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4316 >>> ExtendedContext.logical_xor(Decimal('1'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4317 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4318 >>> ExtendedContext.logical_xor(Decimal('1'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4319 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4320 >>> ExtendedContext.logical_xor(Decimal('1100'), Decimal('1010'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4321 Decimal('110')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4322 >>> ExtendedContext.logical_xor(Decimal('1111'), Decimal('10'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4323 Decimal('1101')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4324 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4325 return a.logical_xor(b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4326
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4327 def max(self, a,b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4328 """max compares two values numerically and returns the maximum.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4329
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4330 If either operand is a NaN then the general rules apply.
44701
2f11f7d9bdc8 Docstring typos
Andrew M. Kuchling <amk@amk.ca>
parents: 44650
diff changeset
4331 Otherwise, the operands are compared as though by the compare
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4332 operation. If they are numerically equal then the left-hand operand
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4333 is chosen as the result. Otherwise the maximum (closer to positive
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4334 infinity) of the two operands is chosen as the result.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4335
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4336 >>> ExtendedContext.max(Decimal('3'), Decimal('2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4337 Decimal('3')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4338 >>> ExtendedContext.max(Decimal('-10'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4339 Decimal('3')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4340 >>> ExtendedContext.max(Decimal('1.0'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4341 Decimal('1')
33157
b2f427db228b Revise max() and min() to comply with the 8/2/2004 update to the specification
Raymond Hettinger <python@rcn.com>
parents: 33044
diff changeset
4342 >>> ExtendedContext.max(Decimal('7'), Decimal('NaN'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4343 Decimal('7')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4344 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4345 return a.max(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4346
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4347 def max_mag(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4348 """Compares the values numerically with their sign ignored."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4349 return a.max_mag(b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4350
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4351 def min(self, a,b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4352 """min compares two values numerically and returns the minimum.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4353
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4354 If either operand is a NaN then the general rules apply.
44701
2f11f7d9bdc8 Docstring typos
Andrew M. Kuchling <amk@amk.ca>
parents: 44650
diff changeset
4355 Otherwise, the operands are compared as though by the compare
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4356 operation. If they are numerically equal then the left-hand operand
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4357 is chosen as the result. Otherwise the minimum (closer to negative
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4358 infinity) of the two operands is chosen as the result.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4359
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4360 >>> ExtendedContext.min(Decimal('3'), Decimal('2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4361 Decimal('2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4362 >>> ExtendedContext.min(Decimal('-10'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4363 Decimal('-10')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4364 >>> ExtendedContext.min(Decimal('1.0'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4365 Decimal('1.0')
33157
b2f427db228b Revise max() and min() to comply with the 8/2/2004 update to the specification
Raymond Hettinger <python@rcn.com>
parents: 33044
diff changeset
4366 >>> ExtendedContext.min(Decimal('7'), Decimal('NaN'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4367 Decimal('7')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4368 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4369 return a.min(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4370
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4371 def min_mag(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4372 """Compares the values numerically with their sign ignored."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4373 return a.min_mag(b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4374
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4375 def minus(self, a):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4376 """Minus corresponds to unary prefix minus in Python.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4377
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4378 The operation is evaluated using the same rules as subtract; the
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4379 operation minus(a) is calculated as subtract('0', a) where the '0'
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4380 has the same exponent as the operand.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4381
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4382 >>> ExtendedContext.minus(Decimal('1.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4383 Decimal('-1.3')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4384 >>> ExtendedContext.minus(Decimal('-1.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4385 Decimal('1.3')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4386 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4387 return a.__neg__(context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4388
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4389 def multiply(self, a, b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4390 """multiply multiplies two operands.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4391
39120
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
4392 If either operand is a special value then the general rules apply.
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
4393 Otherwise, the operands are multiplied together ('long multiplication'),
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
4394 resulting in a number which may be as long as the sum of the lengths
1d7da8608031 Revert r50706 (Whitespace normalization) and
Martin v. Löwis <martin@v.loewis.de>
parents: 39117
diff changeset
4395 of the two operands.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4396
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4397 >>> ExtendedContext.multiply(Decimal('1.20'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4398 Decimal('3.60')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4399 >>> ExtendedContext.multiply(Decimal('7'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4400 Decimal('21')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4401 >>> ExtendedContext.multiply(Decimal('0.9'), Decimal('0.8'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4402 Decimal('0.72')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4403 >>> ExtendedContext.multiply(Decimal('0.9'), Decimal('-0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4404 Decimal('-0.0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4405 >>> ExtendedContext.multiply(Decimal('654321'), Decimal('654321'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4406 Decimal('4.28135971E+11')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4407 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4408 return a.__mul__(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4409
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4410 def next_minus(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4411 """Returns the largest representable number smaller than a.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4412
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4413 >>> c = ExtendedContext.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4414 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4415 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4416 >>> ExtendedContext.next_minus(Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4417 Decimal('0.999999999')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4418 >>> c.next_minus(Decimal('1E-1007'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4419 Decimal('0E-1007')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4420 >>> ExtendedContext.next_minus(Decimal('-1.00000003'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4421 Decimal('-1.00000004')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4422 >>> c.next_minus(Decimal('Infinity'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4423 Decimal('9.99999999E+999')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4424 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4425 return a.next_minus(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4426
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4427 def next_plus(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4428 """Returns the smallest representable number larger than a.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4429
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4430 >>> c = ExtendedContext.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4431 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4432 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4433 >>> ExtendedContext.next_plus(Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4434 Decimal('1.00000001')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4435 >>> c.next_plus(Decimal('-1E-1007'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4436 Decimal('-0E-1007')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4437 >>> ExtendedContext.next_plus(Decimal('-1.00000003'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4438 Decimal('-1.00000002')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4439 >>> c.next_plus(Decimal('-Infinity'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4440 Decimal('-9.99999999E+999')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4441 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4442 return a.next_plus(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4443
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4444 def next_toward(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4445 """Returns the number closest to a, in direction towards b.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4446
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4447 The result is the closest representable number from the first
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4448 operand (but not the first operand) that is in the direction
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4449 towards the second operand, unless the operands have the same
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4450 value.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4451
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4452 >>> c = ExtendedContext.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4453 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4454 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4455 >>> c.next_toward(Decimal('1'), Decimal('2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4456 Decimal('1.00000001')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4457 >>> c.next_toward(Decimal('-1E-1007'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4458 Decimal('-0E-1007')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4459 >>> c.next_toward(Decimal('-1.00000003'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4460 Decimal('-1.00000002')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4461 >>> c.next_toward(Decimal('1'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4462 Decimal('0.999999999')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4463 >>> c.next_toward(Decimal('1E-1007'), Decimal('-100'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4464 Decimal('0E-1007')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4465 >>> c.next_toward(Decimal('-1.00000003'), Decimal('-10'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4466 Decimal('-1.00000004')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4467 >>> c.next_toward(Decimal('0.00'), Decimal('-0.0000'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4468 Decimal('-0.00')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4469 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4470 return a.next_toward(b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4471
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4472 def normalize(self, a):
32496
9c87518faf6b * Fixup docstrings
Raymond Hettinger <python@rcn.com>
parents: 32489
diff changeset
4473 """normalize reduces an operand to its simplest form.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4474
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4475 Essentially a plus operation with all trailing zeros removed from the
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4476 result.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4477
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4478 >>> ExtendedContext.normalize(Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4479 Decimal('2.1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4480 >>> ExtendedContext.normalize(Decimal('-2.0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4481 Decimal('-2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4482 >>> ExtendedContext.normalize(Decimal('1.200'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4483 Decimal('1.2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4484 >>> ExtendedContext.normalize(Decimal('-120'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4485 Decimal('-1.2E+2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4486 >>> ExtendedContext.normalize(Decimal('120.00'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4487 Decimal('1.2E+2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4488 >>> ExtendedContext.normalize(Decimal('0.00'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4489 Decimal('0')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4490 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4491 return a.normalize(context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4492
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4493 def number_class(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4494 """Returns an indication of the class of the operand.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4495
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4496 The class is one of the following strings:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4497 -sNaN
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4498 -NaN
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4499 -Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4500 -Normal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4501 -Subnormal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4502 -Zero
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4503 +Zero
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4504 +Subnormal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4505 +Normal
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4506 +Infinity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4507
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4508 >>> c = Context(ExtendedContext)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4509 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4510 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4511 >>> c.number_class(Decimal('Infinity'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4512 '+Infinity'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4513 >>> c.number_class(Decimal('1E-10'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4514 '+Normal'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4515 >>> c.number_class(Decimal('2.50'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4516 '+Normal'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4517 >>> c.number_class(Decimal('0.1E-999'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4518 '+Subnormal'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4519 >>> c.number_class(Decimal('0'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4520 '+Zero'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4521 >>> c.number_class(Decimal('-0'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4522 '-Zero'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4523 >>> c.number_class(Decimal('-0.1E-999'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4524 '-Subnormal'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4525 >>> c.number_class(Decimal('-1E-10'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4526 '-Normal'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4527 >>> c.number_class(Decimal('-2.50'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4528 '-Normal'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4529 >>> c.number_class(Decimal('-Infinity'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4530 '-Infinity'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4531 >>> c.number_class(Decimal('NaN'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4532 'NaN'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4533 >>> c.number_class(Decimal('-NaN'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4534 'NaN'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4535 >>> c.number_class(Decimal('sNaN'))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4536 'sNaN'
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4537 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4538 return a.number_class(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4539
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4540 def plus(self, a):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4541 """Plus corresponds to unary prefix plus in Python.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4542
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4543 The operation is evaluated using the same rules as add; the
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4544 operation plus(a) is calculated as add('0', a) where the '0'
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4545 has the same exponent as the operand.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4546
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4547 >>> ExtendedContext.plus(Decimal('1.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4548 Decimal('1.3')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4549 >>> ExtendedContext.plus(Decimal('-1.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4550 Decimal('-1.3')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4551 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4552 return a.__pos__(context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4553
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4554 def power(self, a, b, modulo=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4555 """Raises a to the power of b, to modulo if given.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4556
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4557 With two arguments, compute a**b. If a is negative then b
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4558 must be integral. The result will be inexact unless b is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4559 integral and the result is finite and can be expressed exactly
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4560 in 'precision' digits.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4561
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4562 With three arguments, compute (a**b) % modulo. For the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4563 three argument form, the following restrictions on the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4564 arguments hold:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4565
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4566 - all three arguments must be integral
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4567 - b must be nonnegative
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4568 - at least one of a or b must be nonzero
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4569 - modulo must be nonzero and have at most 'precision' digits
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4570
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4571 The result of pow(a, b, modulo) is identical to the result
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4572 that would be obtained by computing (a**b) % modulo with
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4573 unbounded precision, but is computed more efficiently. It is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4574 always exact.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4575
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4576 >>> c = ExtendedContext.copy()
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4577 >>> c.Emin = -999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4578 >>> c.Emax = 999
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4579 >>> c.power(Decimal('2'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4580 Decimal('8')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4581 >>> c.power(Decimal('-2'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4582 Decimal('-8')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4583 >>> c.power(Decimal('2'), Decimal('-3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4584 Decimal('0.125')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4585 >>> c.power(Decimal('1.7'), Decimal('8'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4586 Decimal('69.7575744')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4587 >>> c.power(Decimal('10'), Decimal('0.301029996'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4588 Decimal('2.00000000')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4589 >>> c.power(Decimal('Infinity'), Decimal('-1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4590 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4591 >>> c.power(Decimal('Infinity'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4592 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4593 >>> c.power(Decimal('Infinity'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4594 Decimal('Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4595 >>> c.power(Decimal('-Infinity'), Decimal('-1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4596 Decimal('-0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4597 >>> c.power(Decimal('-Infinity'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4598 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4599 >>> c.power(Decimal('-Infinity'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4600 Decimal('-Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4601 >>> c.power(Decimal('-Infinity'), Decimal('2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4602 Decimal('Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4603 >>> c.power(Decimal('0'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4604 Decimal('NaN')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4605
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4606 >>> c.power(Decimal('3'), Decimal('7'), Decimal('16'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4607 Decimal('11')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4608 >>> c.power(Decimal('-3'), Decimal('7'), Decimal('16'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4609 Decimal('-11')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4610 >>> c.power(Decimal('-3'), Decimal('8'), Decimal('16'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4611 Decimal('1')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4612 >>> c.power(Decimal('3'), Decimal('7'), Decimal('-16'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4613 Decimal('11')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4614 >>> c.power(Decimal('23E12345'), Decimal('67E189'), Decimal('123456789'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4615 Decimal('11729830')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4616 >>> c.power(Decimal('-0'), Decimal('17'), Decimal('1729'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4617 Decimal('-0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4618 >>> c.power(Decimal('-23'), Decimal('0'), Decimal('65537'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4619 Decimal('1')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4620 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4621 return a.__pow__(b, modulo, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4622
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4623 def quantize(self, a, b):
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4624 """Returns a value equal to 'a' (rounded), having the exponent of 'b'.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4625
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4626 The coefficient of the result is derived from that of the left-hand
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4627 operand. It may be rounded using the current rounding setting (if the
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4628 exponent is being increased), multiplied by a positive power of ten (if
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4629 the exponent is being decreased), or is unchanged (if the exponent is
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4630 already equal to that of the right-hand operand).
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4631
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4632 Unlike other operations, if the length of the coefficient after the
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4633 quantize operation would be greater than precision then an Invalid
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4634 operation condition is raised. This guarantees that, unless there is
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4635 an error condition, the exponent of the result of a quantize is always
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4636 equal to that of the right-hand operand.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4637
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4638 Also unlike other operations, quantize will never raise Underflow, even
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4639 if the result is subnormal and inexact.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4640
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4641 >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('0.001'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4642 Decimal('2.170')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4643 >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('0.01'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4644 Decimal('2.17')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4645 >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('0.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4646 Decimal('2.2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4647 >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('1e+0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4648 Decimal('2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4649 >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('1e+1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4650 Decimal('0E+1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4651 >>> ExtendedContext.quantize(Decimal('-Inf'), Decimal('Infinity'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4652 Decimal('-Infinity')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4653 >>> ExtendedContext.quantize(Decimal('2'), Decimal('Infinity'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4654 Decimal('NaN')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4655 >>> ExtendedContext.quantize(Decimal('-0.1'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4656 Decimal('-0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4657 >>> ExtendedContext.quantize(Decimal('-0'), Decimal('1e+5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4658 Decimal('-0E+5')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4659 >>> ExtendedContext.quantize(Decimal('+35236450.6'), Decimal('1e-2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4660 Decimal('NaN')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4661 >>> ExtendedContext.quantize(Decimal('-35236450.6'), Decimal('1e-2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4662 Decimal('NaN')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4663 >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e-1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4664 Decimal('217.0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4665 >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e-0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4666 Decimal('217')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4667 >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e+1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4668 Decimal('2.2E+2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4669 >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e+2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4670 Decimal('2E+2')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4671 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4672 return a.quantize(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4673
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4674 def radix(self):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4675 """Just returns 10, as this is Decimal, :)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4676
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4677 >>> ExtendedContext.radix()
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4678 Decimal('10')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4679 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4680 return Decimal(10)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4681
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4682 def remainder(self, a, b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4683 """Returns the remainder from integer division.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4684
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4685 The result is the residue of the dividend after the operation of
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4686 calculating integer division as described for divide-integer, rounded
41532
4b9fa8092e82 Whitespace normalization. Ugh, we really need to do this more often.
Neal Norwitz <nnorwitz@gmail.com>
parents: 41418
diff changeset
4687 to precision digits if necessary. The sign of the result, if
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4688 non-zero, is the same as that of the original dividend.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4689
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4690 This operation will fail under the same conditions as integer division
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4691 (that is, if integer division on the same two operands would fail, the
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4692 remainder cannot be calculated).
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4693
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4694 >>> ExtendedContext.remainder(Decimal('2.1'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4695 Decimal('2.1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4696 >>> ExtendedContext.remainder(Decimal('10'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4697 Decimal('1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4698 >>> ExtendedContext.remainder(Decimal('-10'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4699 Decimal('-1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4700 >>> ExtendedContext.remainder(Decimal('10.2'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4701 Decimal('0.2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4702 >>> ExtendedContext.remainder(Decimal('10'), Decimal('0.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4703 Decimal('0.1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4704 >>> ExtendedContext.remainder(Decimal('3.6'), Decimal('1.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4705 Decimal('1.0')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4706 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4707 return a.__mod__(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4708
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4709 def remainder_near(self, a, b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4710 """Returns to be "a - b * n", where n is the integer nearest the exact
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4711 value of "x / b" (if two integers are equally near then the even one
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4712 is chosen). If the result is equal to 0 then its sign will be the
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4713 sign of a.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4714
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4715 This operation will fail under the same conditions as integer division
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4716 (that is, if integer division on the same two operands would fail, the
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4717 remainder cannot be calculated).
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4718
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4719 >>> ExtendedContext.remainder_near(Decimal('2.1'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4720 Decimal('-0.9')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4721 >>> ExtendedContext.remainder_near(Decimal('10'), Decimal('6'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4722 Decimal('-2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4723 >>> ExtendedContext.remainder_near(Decimal('10'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4724 Decimal('1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4725 >>> ExtendedContext.remainder_near(Decimal('-10'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4726 Decimal('-1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4727 >>> ExtendedContext.remainder_near(Decimal('10.2'), Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4728 Decimal('0.2')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4729 >>> ExtendedContext.remainder_near(Decimal('10'), Decimal('0.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4730 Decimal('0.1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4731 >>> ExtendedContext.remainder_near(Decimal('3.6'), Decimal('1.3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4732 Decimal('-0.3')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4733 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4734 return a.remainder_near(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4735
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4736 def rotate(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4737 """Returns a rotated copy of a, b times.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4738
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4739 The coefficient of the result is a rotated copy of the digits in
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4740 the coefficient of the first operand. The number of places of
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4741 rotation is taken from the absolute value of the second operand,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4742 with the rotation being to the left if the second operand is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4743 positive or to the right otherwise.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4744
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4745 >>> ExtendedContext.rotate(Decimal('34'), Decimal('8'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4746 Decimal('400000003')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4747 >>> ExtendedContext.rotate(Decimal('12'), Decimal('9'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4748 Decimal('12')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4749 >>> ExtendedContext.rotate(Decimal('123456789'), Decimal('-2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4750 Decimal('891234567')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4751 >>> ExtendedContext.rotate(Decimal('123456789'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4752 Decimal('123456789')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4753 >>> ExtendedContext.rotate(Decimal('123456789'), Decimal('+2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4754 Decimal('345678912')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4755 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4756 return a.rotate(b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4757
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4758 def same_quantum(self, a, b):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4759 """Returns True if the two operands have the same exponent.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4760
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4761 The result is never affected by either the sign or the coefficient of
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4762 either operand.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4763
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4764 >>> ExtendedContext.same_quantum(Decimal('2.17'), Decimal('0.001'))
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4765 False
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4766 >>> ExtendedContext.same_quantum(Decimal('2.17'), Decimal('0.01'))
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4767 True
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4768 >>> ExtendedContext.same_quantum(Decimal('2.17'), Decimal('1'))
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4769 False
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4770 >>> ExtendedContext.same_quantum(Decimal('Inf'), Decimal('-Inf'))
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4771 True
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4772 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4773 return a.same_quantum(b)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4774
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4775 def scaleb (self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4776 """Returns the first operand after adding the second value its exp.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4777
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4778 >>> ExtendedContext.scaleb(Decimal('7.50'), Decimal('-2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4779 Decimal('0.0750')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4780 >>> ExtendedContext.scaleb(Decimal('7.50'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4781 Decimal('7.50')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4782 >>> ExtendedContext.scaleb(Decimal('7.50'), Decimal('3'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4783 Decimal('7.50E+3')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4784 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4785 return a.scaleb (b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4786
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4787 def shift(self, a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4788 """Returns a shifted copy of a, b times.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4789
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4790 The coefficient of the result is a shifted copy of the digits
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4791 in the coefficient of the first operand. The number of places
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4792 to shift is taken from the absolute value of the second operand,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4793 with the shift being to the left if the second operand is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4794 positive or to the right otherwise. Digits shifted into the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4795 coefficient are zeros.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4796
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4797 >>> ExtendedContext.shift(Decimal('34'), Decimal('8'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4798 Decimal('400000000')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4799 >>> ExtendedContext.shift(Decimal('12'), Decimal('9'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4800 Decimal('0')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4801 >>> ExtendedContext.shift(Decimal('123456789'), Decimal('-2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4802 Decimal('1234567')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4803 >>> ExtendedContext.shift(Decimal('123456789'), Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4804 Decimal('123456789')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4805 >>> ExtendedContext.shift(Decimal('123456789'), Decimal('+2'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4806 Decimal('345678900')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4807 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4808 return a.shift(b, context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4809
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4810 def sqrt(self, a):
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4811 """Square root of a non-negative number to context precision.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4812
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4813 If the result must be inexact, it is rounded using the round-half-even
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4814 algorithm.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4815
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4816 >>> ExtendedContext.sqrt(Decimal('0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4817 Decimal('0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4818 >>> ExtendedContext.sqrt(Decimal('-0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4819 Decimal('-0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4820 >>> ExtendedContext.sqrt(Decimal('0.39'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4821 Decimal('0.624499800')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4822 >>> ExtendedContext.sqrt(Decimal('100'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4823 Decimal('10')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4824 >>> ExtendedContext.sqrt(Decimal('1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4825 Decimal('1')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4826 >>> ExtendedContext.sqrt(Decimal('1.0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4827 Decimal('1.0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4828 >>> ExtendedContext.sqrt(Decimal('1.00'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4829 Decimal('1.0')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4830 >>> ExtendedContext.sqrt(Decimal('7'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4831 Decimal('2.64575131')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4832 >>> ExtendedContext.sqrt(Decimal('10'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4833 Decimal('3.16227766')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4834 >>> ExtendedContext.prec
32481
b835d5c61d86 * Make the tests independent of the default precision.
Raymond Hettinger <python@rcn.com>
parents: 32477
diff changeset
4835 9
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4836 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4837 return a.sqrt(context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4838
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4839 def subtract(self, a, b):
35379
43211be0de41 bug [ 1266296 ] Mistakes in decimal.Context.subtract documentation
Georg Brandl <georg@python.org>
parents: 35113
diff changeset
4840 """Return the difference between the two operands.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4841
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4842 >>> ExtendedContext.subtract(Decimal('1.3'), Decimal('1.07'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4843 Decimal('0.23')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4844 >>> ExtendedContext.subtract(Decimal('1.3'), Decimal('1.30'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4845 Decimal('0.00')
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
4846 >>> ExtendedContext.subtract(Decimal('1.3'), Decimal('2.07'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4847 Decimal('-0.77')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4848 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4849 return a.__sub__(b, context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4850
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4851 def to_eng_string(self, a):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4852 """Converts a number to a string, using scientific notation.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4853
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4854 The operation is not affected by the context.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4855 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4856 return a.to_eng_string(context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4857
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4858 def to_sci_string(self, a):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4859 """Converts a number to a string, using scientific notation.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4860
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4861 The operation is not affected by the context.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4862 """
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4863 return a.__str__(context=self)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4864
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4865 def to_integral_exact(self, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4866 """Rounds to an integer.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4867
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4868 When the operand has a negative exponent, the result is the same
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4869 as using the quantize() operation using the given operand as the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4870 left-hand-operand, 1E+0 as the right-hand-operand, and the precision
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4871 of the operand as the precision setting; Inexact and Rounded flags
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4872 are allowed in this operation. The rounding mode is taken from the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4873 context.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4874
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4875 >>> ExtendedContext.to_integral_exact(Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4876 Decimal('2')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4877 >>> ExtendedContext.to_integral_exact(Decimal('100'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4878 Decimal('100')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4879 >>> ExtendedContext.to_integral_exact(Decimal('100.0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4880 Decimal('100')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4881 >>> ExtendedContext.to_integral_exact(Decimal('101.5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4882 Decimal('102')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4883 >>> ExtendedContext.to_integral_exact(Decimal('-101.5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4884 Decimal('-102')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4885 >>> ExtendedContext.to_integral_exact(Decimal('10E+5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4886 Decimal('1.0E+6')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4887 >>> ExtendedContext.to_integral_exact(Decimal('7.89E+77'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4888 Decimal('7.89E+77')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4889 >>> ExtendedContext.to_integral_exact(Decimal('-Inf'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4890 Decimal('-Infinity')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4891 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4892 return a.to_integral_exact(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4893
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4894 def to_integral_value(self, a):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4895 """Rounds to an integer.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4896
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4897 When the operand has a negative exponent, the result is the same
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4898 as using the quantize() operation using the given operand as the
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4899 left-hand-operand, 1E+0 as the right-hand-operand, and the precision
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4900 of the operand as the precision setting, except that no flags will
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
4901 be set. The rounding mode is taken from the context.
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4902
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4903 >>> ExtendedContext.to_integral_value(Decimal('2.1'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4904 Decimal('2')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4905 >>> ExtendedContext.to_integral_value(Decimal('100'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4906 Decimal('100')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4907 >>> ExtendedContext.to_integral_value(Decimal('100.0'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4908 Decimal('100')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4909 >>> ExtendedContext.to_integral_value(Decimal('101.5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4910 Decimal('102')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4911 >>> ExtendedContext.to_integral_value(Decimal('-101.5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4912 Decimal('-102')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4913 >>> ExtendedContext.to_integral_value(Decimal('10E+5'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4914 Decimal('1.0E+6')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4915 >>> ExtendedContext.to_integral_value(Decimal('7.89E+77'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4916 Decimal('7.89E+77')
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4917 >>> ExtendedContext.to_integral_value(Decimal('-Inf'))
45321
33122ff83405 Fix decimal repr which should have used single quotes like other reprs.
Raymond Hettinger <python@rcn.com>
parents: 45293
diff changeset
4918 Decimal('-Infinity')
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4919 """
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4920 return a.to_integral_value(context=self)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4921
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4922 # the method name changed, but we provide also the old one, for compatibility
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4923 to_integral = to_integral_value
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4924
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4925 class _WorkRep(object):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4926 __slots__ = ('sign','int','exp')
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
4927 # sign: 0 or 1
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
4928 # int: int or long
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4929 # exp: None, int, or string
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4930
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4931 def __init__(self, value=None):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4932 if value is None:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4933 self.sign = None
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
4934 self.int = 0
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4935 self.exp = None
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
4936 elif isinstance(value, Decimal):
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
4937 self.sign = value._sign
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
4938 self.int = int(value._int)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4939 self.exp = value._exp
33851
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
4940 else:
2ee0301b483c SF patch #1053375.
Raymond Hettinger <python@rcn.com>
parents: 33845
diff changeset
4941 # assert isinstance(value, tuple)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4942 self.sign = value[0]
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4943 self.int = value[1]
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4944 self.exp = value[2]
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4945
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4946 def __repr__(self):
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4947 return "(%r, %r, %r)" % (self.sign, self.int, self.exp)
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4948
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4949 __str__ = __repr__
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4950
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4951
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4952
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
4953 def _normalize(op1, op2, prec = 0):
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4954 """Normalizes op1, op2 to have the same exp and length of coefficient.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4955
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4956 Done during addition.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4957 """
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4958 if op1.exp < op2.exp:
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4959 tmp = op2
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4960 other = op1
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4961 else:
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4962 tmp = op1
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4963 other = op2
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4964
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4965 # Let exp = min(tmp.exp - 1, tmp.adjusted() - precision - 1).
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4966 # Then adding 10**exp to tmp has the same effect (after rounding)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4967 # as adding any positive quantity smaller than 10**exp; similarly
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4968 # for subtraction. So if other is smaller than 10**exp we replace
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4969 # it with 10**exp. This avoids tmp.exp - other.exp getting too large.
44328
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
4970 tmp_len = len(str(tmp.int))
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
4971 other_len = len(str(other.int))
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
4972 exp = tmp.exp + min(-1, tmp_len - prec - 2)
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
4973 if other_len + other.exp - 1 < exp:
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
4974 other.int = 1
09f74316d5fb Removed the private _rounding_decision: it was not needed, and the code
Facundo Batista <facundobatista@gmail.com>
parents: 44148
diff changeset
4975 other.exp = exp
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4976
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4977 tmp.int *= 10 ** (tmp.exp - other.exp)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4978 tmp.exp = other.exp
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4979 return op1, op2
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
4980
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4981 ##### Integer arithmetic functions used by ln, log10, exp and __pow__ #####
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4982
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4983 # This function from Tim Peters was taken from here:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4984 # http://mail.python.org/pipermail/python-list/1999-July/007758.html
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4985 # The correction being in the function definition is for speed, and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4986 # the whole function is not resolved with math.log because of avoiding
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4987 # the use of floats.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4988 def _nbits(n, correction = {
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4989 '0': 4, '1': 3, '2': 2, '3': 2,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4990 '4': 1, '5': 1, '6': 1, '7': 1,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4991 '8': 0, '9': 0, 'a': 0, 'b': 0,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4992 'c': 0, 'd': 0, 'e': 0, 'f': 0}):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4993 """Number of bits in binary representation of the positive integer n,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4994 or 0 if n == 0.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4995 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4996 if n < 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4997 raise ValueError("The argument to _nbits should be nonnegative.")
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4998 hex_n = "%x" % n
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
4999 return 4*len(hex_n) - correction[hex_n[0]]
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5000
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5001 def _sqrt_nearest(n, a):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5002 """Closest integer to the square root of the positive integer n. a is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5003 an initial approximation to the square root. Any positive integer
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5004 will do for a, but the closer a is to the square root of n the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5005 faster convergence will be.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5006
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5007 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5008 if n <= 0 or a <= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5009 raise ValueError("Both arguments to _sqrt_nearest should be positive.")
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5010
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5011 b=0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5012 while a != b:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5013 b, a = a, a--n//a>>1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5014 return a
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5015
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5016 def _rshift_nearest(x, shift):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5017 """Given an integer x and a nonnegative integer shift, return closest
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5018 integer to x / 2**shift; use round-to-even in case of a tie.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5019
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5020 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5021 b, q = 1L << shift, x >> shift
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5022 return q + (2*(x & (b-1)) + (q&1) > b)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5023
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5024 def _div_nearest(a, b):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5025 """Closest integer to a/b, a and b positive integers; rounds to even
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5026 in the case of a tie.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5027
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5028 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5029 q, r = divmod(a, b)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5030 return q + (2*r + (q&1) > b)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5031
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5032 def _ilog(x, M, L = 8):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5033 """Integer approximation to M*log(x/M), with absolute error boundable
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5034 in terms only of x/M.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5035
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5036 Given positive integers x and M, return an integer approximation to
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5037 M * log(x/M). For L = 8 and 0.1 <= x/M <= 10 the difference
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5038 between the approximation and the exact result is at most 22. For
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5039 L = 8 and 1.0 <= x/M <= 10.0 the difference is at most 15. In
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5040 both cases these are upper bounds on the error; it will usually be
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5041 much smaller."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5042
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5043 # The basic algorithm is the following: let log1p be the function
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5044 # log1p(x) = log(1+x). Then log(x/M) = log1p((x-M)/M). We use
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5045 # the reduction
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5046 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5047 # log1p(y) = 2*log1p(y/(1+sqrt(1+y)))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5048 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5049 # repeatedly until the argument to log1p is small (< 2**-L in
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5050 # absolute value). For small y we can use the Taylor series
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5051 # expansion
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5052 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5053 # log1p(y) ~ y - y**2/2 + y**3/3 - ... - (-y)**T/T
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5054 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5055 # truncating at T such that y**T is small enough. The whole
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5056 # computation is carried out in a form of fixed-point arithmetic,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5057 # with a real number z being represented by an integer
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5058 # approximation to z*M. To avoid loss of precision, the y below
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5059 # is actually an integer approximation to 2**R*y*M, where R is the
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5060 # number of reductions performed so far.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5061
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5062 y = x-M
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5063 # argument reduction; R = number of reductions performed
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5064 R = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5065 while (R <= L and long(abs(y)) << L-R >= M or
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5066 R > L and abs(y) >> R-L >= M):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5067 y = _div_nearest(long(M*y) << 1,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5068 M + _sqrt_nearest(M*(M+_rshift_nearest(y, R)), M))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5069 R += 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5070
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5071 # Taylor series with T terms
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5072 T = -int(-10*len(str(M))//(3*L))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5073 yshift = _rshift_nearest(y, R)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5074 w = _div_nearest(M, T)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5075 for k in xrange(T-1, 0, -1):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5076 w = _div_nearest(M, k) - _div_nearest(yshift*w, M)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5077
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5078 return _div_nearest(w*y, M)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5079
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5080 def _dlog10(c, e, p):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5081 """Given integers c, e and p with c > 0, p >= 0, compute an integer
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5082 approximation to 10**p * log10(c*10**e), with an absolute error of
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5083 at most 1. Assumes that c*10**e is not exactly 1."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5084
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5085 # increase precision by 2; compensate for this by dividing
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5086 # final result by 100
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5087 p += 2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5088
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5089 # write c*10**e as d*10**f with either:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5090 # f >= 0 and 1 <= d <= 10, or
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5091 # f <= 0 and 0.1 <= d <= 1.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5092 # Thus for c*10**e close to 1, f = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5093 l = len(str(c))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5094 f = e+l - (e+l >= 1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5095
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5096 if p > 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5097 M = 10**p
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5098 k = e+p-f
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5099 if k >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5100 c *= 10**k
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5101 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5102 c = _div_nearest(c, 10**-k)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5103
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5104 log_d = _ilog(c, M) # error < 5 + 22 = 27
43455
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5105 log_10 = _log10_digits(p) # error < 1
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5106 log_d = _div_nearest(log_d*M, log_10)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5107 log_tenpower = f*M # exact
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5108 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5109 log_d = 0 # error < 2.31
48847
Neal Norwitz <nnorwitz@gmail.com>
parents: 47961
diff changeset
5110 log_tenpower = _div_nearest(f, 10**-p) # error < 0.5
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5111
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5112 return _div_nearest(log_tenpower+log_d, 100)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5113
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5114 def _dlog(c, e, p):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5115 """Given integers c, e and p with c > 0, compute an integer
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5116 approximation to 10**p * log(c*10**e), with an absolute error of
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5117 at most 1. Assumes that c*10**e is not exactly 1."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5118
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5119 # Increase precision by 2. The precision increase is compensated
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5120 # for at the end with a division by 100.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5121 p += 2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5122
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5123 # rewrite c*10**e as d*10**f with either f >= 0 and 1 <= d <= 10,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5124 # or f <= 0 and 0.1 <= d <= 1. Then we can compute 10**p * log(c*10**e)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5125 # as 10**p * log(d) + 10**p*f * log(10).
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5126 l = len(str(c))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5127 f = e+l - (e+l >= 1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5128
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5129 # compute approximation to 10**p*log(d), with error < 27
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5130 if p > 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5131 k = e+p-f
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5132 if k >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5133 c *= 10**k
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5134 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5135 c = _div_nearest(c, 10**-k) # error of <= 0.5 in c
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5136
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5137 # _ilog magnifies existing error in c by a factor of at most 10
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5138 log_d = _ilog(c, 10**p) # error < 5 + 22 = 27
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5139 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5140 # p <= 0: just approximate the whole thing by 0; error < 2.31
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5141 log_d = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5142
43455
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5143 # compute approximation to f*10**p*log(10), with error < 11.
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5144 if f:
43455
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5145 extra = len(str(abs(f)))-1
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5146 if p + extra >= 0:
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5147 # error in f * _log10_digits(p+extra) < |f| * 1 = |f|
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5148 # after division, error < |f|/10**extra + 0.5 < 10 + 0.5 < 11
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5149 f_log_ten = _div_nearest(f*_log10_digits(p+extra), 10**extra)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5150 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5151 f_log_ten = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5152 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5153 f_log_ten = 0
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5154
43455
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5155 # error in sum < 11+27 = 38; error after division < 0.38 + 0.5 < 1
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5156 return _div_nearest(f_log_ten + log_d, 100)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5157
43455
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5158 class _Log10Memoize(object):
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5159 """Class to compute, store, and allow retrieval of, digits of the
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5160 constant log(10) = 2.302585.... This constant is needed by
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5161 Decimal.ln, Decimal.log10, Decimal.exp and Decimal.__pow__."""
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5162 def __init__(self):
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5163 self.digits = "23025850929940456840179914546843642076011014886"
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5164
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5165 def getdigits(self, p):
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5166 """Given an integer p >= 0, return floor(10**p)*log(10).
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5167
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5168 For example, self.getdigits(3) returns 2302.
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5169 """
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5170 # digits are stored as a string, for quick conversion to
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5171 # integer in the case that we've already computed enough
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5172 # digits; the stored digits should always be correct
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5173 # (truncated, not rounded to nearest).
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5174 if p < 0:
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5175 raise ValueError("p should be nonnegative")
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5176
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5177 if p >= len(self.digits):
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5178 # compute p+3, p+6, p+9, ... digits; continue until at
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5179 # least one of the extra digits is nonzero
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5180 extra = 3
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5181 while True:
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5182 # compute p+extra digits, correct to within 1ulp
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5183 M = 10**(p+extra+2)
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5184 digits = str(_div_nearest(_ilog(10*M, M), 100))
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5185 if digits[-extra:] != '0'*extra:
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5186 break
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5187 extra += 3
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5188 # keep all reliable digits so far; remove trailing zeros
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5189 # and next nonzero digit
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5190 self.digits = digits.rstrip('0')[:-1]
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5191 return int(self.digits[:p+1])
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5192
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5193 _log10_digits = _Log10Memoize().getdigits
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5194
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5195 def _iexp(x, M, L=8):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5196 """Given integers x and M, M > 0, such that x/M is small in absolute
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5197 value, compute an integer approximation to M*exp(x/M). For 0 <=
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5198 x/M <= 2.4, the absolute error in the result is bounded by 60 (and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5199 is usually much smaller)."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5200
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5201 # Algorithm: to compute exp(z) for a real number z, first divide z
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5202 # by a suitable power R of 2 so that |z/2**R| < 2**-L. Then
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5203 # compute expm1(z/2**R) = exp(z/2**R) - 1 using the usual Taylor
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5204 # series
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5205 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5206 # expm1(x) = x + x**2/2! + x**3/3! + ...
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5207 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5208 # Now use the identity
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5209 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5210 # expm1(2x) = expm1(x)*(expm1(x)+2)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5211 #
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5212 # R times to compute the sequence expm1(z/2**R),
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5213 # expm1(z/2**(R-1)), ... , exp(z/2), exp(z).
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5214
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5215 # Find R such that x/2**R/M <= 2**-L
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5216 R = _nbits((long(x)<<L)//M)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5217
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5218 # Taylor series. (2**L)**T > M
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5219 T = -int(-10*len(str(M))//(3*L))
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5220 y = _div_nearest(x, T)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5221 Mshift = long(M)<<R
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5222 for i in xrange(T-1, 0, -1):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5223 y = _div_nearest(x*(Mshift + y), Mshift * i)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5224
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5225 # Expansion
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5226 for k in xrange(R-1, -1, -1):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5227 Mshift = long(M)<<(k+2)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5228 y = _div_nearest(y*(y+Mshift), Mshift)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5229
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5230 return M+y
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5231
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5232 def _dexp(c, e, p):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5233 """Compute an approximation to exp(c*10**e), with p decimal places of
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5234 precision.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5235
43455
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5236 Returns integers d, f such that:
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5237
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5238 10**(p-1) <= d <= 10**p, and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5239 (d-1)*10**f < exp(c*10**e) < (d+1)*10**f
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5240
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5241 In other words, d*10**f is an approximation to exp(c*10**e) with p
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5242 digits of precision, and with an error in d of at most 1. This is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5243 almost, but not quite, the same as the error being < 1ulp: when d
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5244 = 10**(p-1) the error could be up to 10 ulp."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5245
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5246 # we'll call iexp with M = 10**(p+2), giving p+3 digits of precision
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5247 p += 2
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5248
43455
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5249 # compute log(10) with extra precision = adjusted exponent of c*10**e
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5250 extra = max(0, e + len(str(c)) - 1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5251 q = p + extra
43455
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5252
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5253 # compute quotient c*10**e/(log(10)) = c*10**(e+q)/(log(10)*10**q),
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5254 # rounding down
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5255 shift = e+q
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5256 if shift >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5257 cshift = c*10**shift
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5258 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5259 cshift = c//10**-shift
43455
7943262e5fc4 Added a class to store the digits of log(10), so that they can be made
Facundo Batista <facundobatista@gmail.com>
parents: 43454
diff changeset
5260 quot, rem = divmod(cshift, _log10_digits(q))
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5261
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5262 # reduce remainder back to original precision
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5263 rem = _div_nearest(rem, 10**extra)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5264
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5265 # error in result of _iexp < 120; error after division < 0.62
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5266 return _div_nearest(_iexp(rem, 10**p), 1000), quot - p + 3
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5267
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5268 def _dpower(xc, xe, yc, ye, p):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5269 """Given integers xc, xe, yc and ye representing Decimals x = xc*10**xe and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5270 y = yc*10**ye, compute x**y. Returns a pair of integers (c, e) such that:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5271
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5272 10**(p-1) <= c <= 10**p, and
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5273 (c-1)*10**e < x**y < (c+1)*10**e
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5274
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5275 in other words, c*10**e is an approximation to x**y with p digits
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5276 of precision, and with an error in c of at most 1. (This is
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5277 almost, but not quite, the same as the error being < 1ulp: when c
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5278 == 10**(p-1) we can only guarantee error < 10ulp.)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5279
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5280 We assume that: x is positive and not equal to 1, and y is nonzero.
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5281 """
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5282
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5283 # Find b such that 10**(b-1) <= |y| <= 10**b
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5284 b = len(str(abs(yc))) + ye
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5285
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5286 # log(x) = lxc*10**(-p-b-1), to p+b+1 places after the decimal point
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5287 lxc = _dlog(xc, xe, p+b+1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5288
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5289 # compute product y*log(x) = yc*lxc*10**(-p-b-1+ye) = pc*10**(-p-1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5290 shift = ye-b
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5291 if shift >= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5292 pc = lxc*yc*10**shift
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5293 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5294 pc = _div_nearest(lxc*yc, 10**-shift)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5295
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5296 if pc == 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5297 # we prefer a result that isn't exactly 1; this makes it
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5298 # easier to compute a correctly rounded result in __pow__
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5299 if ((len(str(xc)) + xe >= 1) == (yc > 0)): # if x**y > 1:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5300 coeff, exp = 10**(p-1)+1, 1-p
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5301 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5302 coeff, exp = 10**p-1, -p
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5303 else:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5304 coeff, exp = _dexp(pc, -(p+1), p+1)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5305 coeff = _div_nearest(coeff, 10)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5306 exp += 1
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5307
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5308 return coeff, exp
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5309
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5310 def _log10_lb(c, correction = {
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5311 '1': 100, '2': 70, '3': 53, '4': 40, '5': 31,
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5312 '6': 23, '7': 16, '8': 10, '9': 5}):
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5313 """Compute a lower bound for 100*log10(c) for a positive integer c."""
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5314 if c <= 0:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5315 raise ValueError("The argument to _log10_lb should be nonnegative.")
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5316 str_c = str(c)
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5317 return 100*len(str_c) - correction[str_c[0]]
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5318
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
5319 ##### Helper Functions ####################################################
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5320
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5321 def _convert_other(other, raiseit=False):
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
5322 """Convert other to Decimal.
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
5323
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
5324 Verifies that it's ok to use in an implicit construction.
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
5325 """
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
5326 if isinstance(other, Decimal):
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
5327 return other
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
5328 if isinstance(other, (int, long)):
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
5329 return Decimal(other)
43360
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5330 if raiseit:
63f3154c731d Merged the decimal-branch (revisions 54886 to 58140). Decimal is now
Facundo Batista <facundobatista@gmail.com>
parents: 42605
diff changeset
5331 raise TypeError("Unable to convert %s to Decimal" % other)
34812
b016236dfbd9 * Fix decimal's handling of foreign types. Now returns NotImplemented
Raymond Hettinger <python@rcn.com>
parents: 34758
diff changeset
5332 return NotImplemented
33519
139a4012bead SF patch #1020845: Decimal performance enhancements
Raymond Hettinger <python@rcn.com>
parents: 33198
diff changeset
5333
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
5334 ##### Setup Specific Contexts ############################################
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5335
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5336 # The default context prototype used by Context()
32666
c13d911ae05b * Rename "Signals" to "_signals" making it non-public.
Raymond Hettinger <python@rcn.com>
parents: 32576
diff changeset
5337 # Is mutable, so that new contexts can have different default values
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5338
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5339 DefaultContext = Context(
32481
b835d5c61d86 * Make the tests independent of the default precision.
Raymond Hettinger <python@rcn.com>
parents: 32477
diff changeset
5340 prec=28, rounding=ROUND_HALF_EVEN,
32576
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
5341 traps=[DivisionByZero, Overflow, InvalidOperation],
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
5342 flags=[],
32674
3479610fb288 Factor out two unnecessary global variables.
Raymond Hettinger <python@rcn.com>
parents: 32667
diff changeset
5343 Emax=999999999,
3479610fb288 Factor out two unnecessary global variables.
Raymond Hettinger <python@rcn.com>
parents: 32667
diff changeset
5344 Emin=-999999999,
32496
9c87518faf6b * Fixup docstrings
Raymond Hettinger <python@rcn.com>
parents: 32489
diff changeset
5345 capitals=1
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5346 )
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5347
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5348 # Pre-made alternate contexts offered by the specification
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5349 # Don't change these; the user should be able to select these
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5350 # contexts and be able to reproduce results from other implementations
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5351 # of the spec.
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5352
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
5353 BasicContext = Context(
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5354 prec=9, rounding=ROUND_HALF_UP,
32576
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
5355 traps=[DivisionByZero, Overflow, InvalidOperation, Clamped, Underflow],
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
5356 flags=[],
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5357 )
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5358
32482
eccd0fbe0cd5 Namespace cleanups:
Raymond Hettinger <python@rcn.com>
parents: 32481
diff changeset
5359 ExtendedContext = Context(
32481
b835d5c61d86 * Make the tests independent of the default precision.
Raymond Hettinger <python@rcn.com>
parents: 32477
diff changeset
5360 prec=9, rounding=ROUND_HALF_EVEN,
32576
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
5361 traps=[],
83cbc025bfc7 Improve Context construction and representation:
Raymond Hettinger <python@rcn.com>
parents: 32561
diff changeset
5362 flags=[],
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5363 )
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5364
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5365
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5366 ##### crud for parsing strings #############################################
45505
bf8ee593cbad Remove duplicate 'import re' in decimal.py
Mark Dickinson <dickinsm@gmail.com>
parents: 45321
diff changeset
5367 #
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5368 # Regular expression used for parsing numeric strings. Additional
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5369 # comments:
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5370 #
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5371 # 1. Uncomment the two '\s*' lines to allow leading and/or trailing
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5372 # whitespace. But note that the specification disallows whitespace in
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5373 # a numeric string.
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5374 #
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5375 # 2. For finite numbers (not infinities and NaNs) the body of the
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5376 # number between the optional sign and the optional exponent must have
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5377 # at least one decimal digit, possibly after the decimal point. The
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5378 # lookahead expression '(?=\d|\.\d)' checks this.
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5379
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5380 import re
47872
65af544da121 Replace occurrences of '\d' with '[0-9]' in Decimal regex, to make sure
Mark Dickinson <dickinsm@gmail.com>
parents: 46653
diff changeset
5381 _parser = re.compile(r""" # A numeric string consists of:
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5382 # \s*
47872
65af544da121 Replace occurrences of '\d' with '[0-9]' in Decimal regex, to make sure
Mark Dickinson <dickinsm@gmail.com>
parents: 46653
diff changeset
5383 (?P<sign>[-+])? # an optional sign, followed by either...
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5384 (
55519
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
5385 (?=\d|\.\d) # ...a number (with at least one digit)
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
5386 (?P<int>\d*) # having a (possibly empty) integer part
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
5387 (\.(?P<frac>\d*))? # followed by an optional fractional part
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
5388 (E(?P<exp>[-+]?\d+))? # followed by an optional exponent, or...
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5389 |
47872
65af544da121 Replace occurrences of '\d' with '[0-9]' in Decimal regex, to make sure
Mark Dickinson <dickinsm@gmail.com>
parents: 46653
diff changeset
5390 Inf(inity)? # ...an infinity, or...
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5391 |
47872
65af544da121 Replace occurrences of '\d' with '[0-9]' in Decimal regex, to make sure
Mark Dickinson <dickinsm@gmail.com>
parents: 46653
diff changeset
5392 (?P<signal>s)? # ...an (optionally signaling)
65af544da121 Replace occurrences of '\d' with '[0-9]' in Decimal regex, to make sure
Mark Dickinson <dickinsm@gmail.com>
parents: 46653
diff changeset
5393 NaN # NaN
55519
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
5394 (?P<diag>\d*) # with (possibly empty) diagnostic info.
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5395 )
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5396 # \s*
44650
7b798548a4ad Issue 1780: Allow leading and trailing whitespace in Decimal constructor,
Mark Dickinson <dickinsm@gmail.com>
parents: 44631
diff changeset
5397 \Z
55519
8b48b282eba9 Merged revisions 74281 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 52189
diff changeset
5398 """, re.VERBOSE | re.IGNORECASE | re.UNICODE).match
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5399
44121
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
5400 _all_zeros = re.compile('0*$').match
30f54977828b Faster _fix function, and some reordering for a more elegant
Facundo Batista <facundobatista@gmail.com>
parents: 44120
diff changeset
5401 _exact_half = re.compile('50*$').match
45566
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5402
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5403 ##### PEP3101 support functions ##############################################
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5404 # The functions parse_format_specifier and format_align have little to do
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5405 # with the Decimal class, and could potentially be reused for other pure
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5406 # Python numeric classes that want to implement __format__
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5407 #
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5408 # A format specifier for Decimal looks like:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5409 #
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5410 # [[fill]align][sign][0][minimumwidth][.precision][type]
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5411 #
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5412
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5413 _parse_format_specifier_regex = re.compile(r"""\A
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5414 (?:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5415 (?P<fill>.)?
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5416 (?P<align>[<>=^])
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5417 )?
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5418 (?P<sign>[-+ ])?
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5419 (?P<zeropad>0)?
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5420 (?P<minimumwidth>(?!0)\d+)?
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5421 (?:\.(?P<precision>0|(?!0)\d+))?
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5422 (?P<type>[eEfFgG%])?
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5423 \Z
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5424 """, re.VERBOSE)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5425
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5426 del re
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5427
45566
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5428 def _parse_format_specifier(format_spec):
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5429 """Parse and validate a format specifier.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5430
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5431 Turns a standard numeric format specifier into a dict, with the
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5432 following entries:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5433
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5434 fill: fill character to pad field to minimum width
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5435 align: alignment type, either '<', '>', '=' or '^'
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5436 sign: either '+', '-' or ' '
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5437 minimumwidth: nonnegative integer giving minimum width
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5438 precision: nonnegative integer giving precision, or None
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5439 type: one of the characters 'eEfFgG%', or None
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5440 unicode: either True or False (always True for Python 3.x)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5441
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5442 """
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5443 m = _parse_format_specifier_regex.match(format_spec)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5444 if m is None:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5445 raise ValueError("Invalid format specifier: " + format_spec)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5446
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5447 # get the dictionary
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5448 format_dict = m.groupdict()
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5449
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5450 # defaults for fill and alignment
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5451 fill = format_dict['fill']
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5452 align = format_dict['align']
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5453 if format_dict.pop('zeropad') is not None:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5454 # in the face of conflict, refuse the temptation to guess
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5455 if fill is not None and fill != '0':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5456 raise ValueError("Fill character conflicts with '0'"
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5457 " in format specifier: " + format_spec)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5458 if align is not None and align != '=':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5459 raise ValueError("Alignment conflicts with '0' in "
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5460 "format specifier: " + format_spec)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5461 fill = '0'
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5462 align = '='
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5463 format_dict['fill'] = fill or ' '
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5464 format_dict['align'] = align or '<'
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5465
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5466 if format_dict['sign'] is None:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5467 format_dict['sign'] = '-'
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5468
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5469 # turn minimumwidth and precision entries into integers.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5470 # minimumwidth defaults to 0; precision remains None if not given
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5471 format_dict['minimumwidth'] = int(format_dict['minimumwidth'] or '0')
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5472 if format_dict['precision'] is not None:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5473 format_dict['precision'] = int(format_dict['precision'])
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5474
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5475 # if format type is 'g' or 'G' then a precision of 0 makes little
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5476 # sense; convert it to 1. Same if format type is unspecified.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5477 if format_dict['precision'] == 0:
55874
e895ef82c086 Merged revisions 74704 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 55741
diff changeset
5478 if format_dict['type'] is None or format_dict['type'] in 'gG':
45566
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5479 format_dict['precision'] = 1
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5480
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5481 # record whether return type should be str or unicode
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5482 format_dict['unicode'] = isinstance(format_spec, unicode)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5483
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5484 return format_dict
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5485
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5486 def _format_align(body, spec_dict):
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5487 """Given an unpadded, non-aligned numeric string, add padding and
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5488 aligment to conform with the given format specifier dictionary (as
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5489 output from parse_format_specifier).
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5490
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5491 It's assumed that if body is negative then it starts with '-'.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5492 Any leading sign ('-' or '+') is stripped from the body before
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5493 applying the alignment and padding rules, and replaced in the
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5494 appropriate position.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5495
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5496 """
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5497 # figure out the sign; we only examine the first character, so if
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5498 # body has leading whitespace the results may be surprising.
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5499 if len(body) > 0 and body[0] in '-+':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5500 sign = body[0]
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5501 body = body[1:]
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5502 else:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5503 sign = ''
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5504
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5505 if sign != '-':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5506 if spec_dict['sign'] in ' +':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5507 sign = spec_dict['sign']
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5508 else:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5509 sign = ''
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5510
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5511 # how much extra space do we have to play with?
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5512 minimumwidth = spec_dict['minimumwidth']
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5513 fill = spec_dict['fill']
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5514 padding = fill*(max(minimumwidth - (len(sign+body)), 0))
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5515
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5516 align = spec_dict['align']
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5517 if align == '<':
52189
fd4c83928080 Merged revisions 70430 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 51294
diff changeset
5518 result = sign + body + padding
45566
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5519 elif align == '>':
52189
fd4c83928080 Merged revisions 70430 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 51294
diff changeset
5520 result = padding + sign + body
45566
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5521 elif align == '=':
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5522 result = sign + padding + body
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5523 else: #align == '^'
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5524 half = len(padding)//2
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5525 result = padding[:half] + sign + body + padding[half:]
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5526
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5527 # make sure that result is unicode if necessary
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5528 if spec_dict['unicode']:
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5529 result = unicode(result)
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5530
bce4c40df7df Add __format__ method to Decimal, to support PEP 3101
Mark Dickinson <dickinsm@gmail.com>
parents: 45505
diff changeset
5531 return result
43993
a4a140486691 Major change in the internal structure of the Decimal
Facundo Batista <facundobatista@gmail.com>
parents: 43602
diff changeset
5532
41418
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
5533 ##### Useful Constants (internal use only) ################################
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
5534
ae4ced28a839 General clean-up. Lot of margin corrections, comments, some typos.
Facundo Batista <facundobatista@gmail.com>
parents: 40770
diff changeset
5535 # Reusable defaults
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
5536 _Infinity = Decimal('Inf')
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
5537 _NegativeInfinity = Decimal('-Inf')
50471
94ff3de1e1a4 Merged revisions 68182 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50116
diff changeset
5538 _NaN = Decimal('NaN')
50480
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
5539 _Zero = Decimal(0)
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
5540 _One = Decimal(1)
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
5541 _NegativeOne = Decimal(-1)
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
5542
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
5543 # _SignedInfinity[sign] is infinity w/ that sign
f2a5d7828b83 Merged revisions 68191 via svnmerge from
Mark Dickinson <dickinsm@gmail.com>
parents: 50471
diff changeset
5544 _SignedInfinity = (_Infinity, _NegativeInfinity)
32451
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5545
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5546
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5547
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5548 if __name__ == '__main__':
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5549 import doctest, sys
d2c1c7ae7cf4 Move Decimal from the sandbox into production.
Raymond Hettinger <python@rcn.com>
parents:
diff changeset
5550 doctest.testmod(sys.modules[__name__])