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Bug #1396471: Document that Windows' ftell() can return invalid values for text files with UNIX-style line endings.
author Georg Brandl <georg@python.org>
date Fri, 20 Jan 2006 09:14:41 +0000
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children dc6dec156869
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1 \section{Built-in Types \label{types}}
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2
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3 The following sections describe the standard types that are built into
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4 the interpreter. Historically, Python's built-in types have differed
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5 from user-defined types because it was not possible to use the built-in
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6 types as the basis for object-oriented inheritance. With the 2.2
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7 release this situation has started to change, although the intended
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8 unification of user-defined and built-in types is as yet far from
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9 complete.
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10
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11 The principal built-in types are numerics, sequences, mappings, files
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12 classes, instances and exceptions.
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13 \indexii{built-in}{types}
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14
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15 Some operations are supported by several object types; in particular,
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16 practically all objects can be compared, tested for truth value,
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17 and converted to a string (with the \code{`\textrm{\ldots}`} notation,
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18 the equivalent \function{repr()} function, or the slightly different
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19 \function{str()} function). The latter
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20 function is implicitly used when an object is written by the
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21 \keyword{print}\stindex{print} statement.
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22 (Information on \ulink{\keyword{print} statement}{../ref/print.html}
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23 and other language statements can be found in the
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24 \citetitle[../ref/ref.html]{Python Reference Manual} and the
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25 \citetitle[../tut/tut.html]{Python Tutorial}.)
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26
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27
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28 \subsection{Truth Value Testing\label{truth}}
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29
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30 Any object can be tested for truth value, for use in an \keyword{if} or
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31 \keyword{while} condition or as operand of the Boolean operations below.
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32 The following values are considered false:
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33 \stindex{if}
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34 \stindex{while}
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35 \indexii{truth}{value}
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36 \indexii{Boolean}{operations}
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37 \index{false}
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38
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39 \begin{itemize}
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40
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41 \item \code{None}
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42 \withsubitem{(Built-in object)}{\ttindex{None}}
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43
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44 \item \code{False}
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45 \withsubitem{(Built-in object)}{\ttindex{False}}
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46
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47 \item zero of any numeric type, for example, \code{0}, \code{0L},
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48 \code{0.0}, \code{0j}.
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49
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50 \item any empty sequence, for example, \code{''}, \code{()}, \code{[]}.
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51
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52 \item any empty mapping, for example, \code{\{\}}.
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53
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54 \item instances of user-defined classes, if the class defines a
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55 \method{__nonzero__()} or \method{__len__()} method, when that
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56 method returns the integer zero or \class{bool} value
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57 \code{False}.\footnote{Additional
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58 information on these special methods may be found in the
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59 \citetitle[../ref/ref.html]{Python Reference Manual}.}
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60
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61 \end{itemize}
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62
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63 All other values are considered true --- so objects of many types are
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64 always true.
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65 \index{true}
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66
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67 Operations and built-in functions that have a Boolean result always
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68 return \code{0} or \code{False} for false and \code{1} or \code{True}
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69 for true, unless otherwise stated. (Important exception: the Boolean
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70 operations \samp{or}\opindex{or} and \samp{and}\opindex{and} always
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71 return one of their operands.)
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72 \index{False}
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73 \index{True}
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74
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75 \subsection{Boolean Operations ---
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76 \keyword{and}, \keyword{or}, \keyword{not}
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77 \label{boolean}}
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78
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79 These are the Boolean operations, ordered by ascending priority:
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80 \indexii{Boolean}{operations}
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81
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82 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
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83 \lineiii{\var{x} or \var{y}}
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84 {if \var{x} is false, then \var{y}, else \var{x}}{(1)}
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85 \lineiii{\var{x} and \var{y}}
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86 {if \var{x} is false, then \var{x}, else \var{y}}{(1)}
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87 \hline
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88 \lineiii{not \var{x}}
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89 {if \var{x} is false, then \code{True}, else \code{False}}{(2)}
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90 \end{tableiii}
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91 \opindex{and}
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92 \opindex{or}
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93 \opindex{not}
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94
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95 \noindent
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96 Notes:
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97
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98 \begin{description}
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99
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100 \item[(1)]
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101 These only evaluate their second argument if needed for their outcome.
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102
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103 \item[(2)]
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104 \samp{not} has a lower priority than non-Boolean operators, so
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105 \code{not \var{a} == \var{b}} is interpreted as \code{not (\var{a} ==
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106 \var{b})}, and \code{\var{a} == not \var{b}} is a syntax error.
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107
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108 \end{description}
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109
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110
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111 \subsection{Comparisons \label{comparisons}}
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112
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113 Comparison operations are supported by all objects. They all have the
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114 same priority (which is higher than that of the Boolean operations).
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115 Comparisons can be chained arbitrarily; for example, \code{\var{x} <
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116 \var{y} <= \var{z}} is equivalent to \code{\var{x} < \var{y} and
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117 \var{y} <= \var{z}}, except that \var{y} is evaluated only once (but
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118 in both cases \var{z} is not evaluated at all when \code{\var{x} <
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119 \var{y}} is found to be false).
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120 \indexii{chaining}{comparisons}
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121
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122 This table summarizes the comparison operations:
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123
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124 \begin{tableiii}{c|l|c}{code}{Operation}{Meaning}{Notes}
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125 \lineiii{<}{strictly less than}{}
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126 \lineiii{<=}{less than or equal}{}
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127 \lineiii{>}{strictly greater than}{}
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128 \lineiii{>=}{greater than or equal}{}
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129 \lineiii{==}{equal}{}
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130 \lineiii{!=}{not equal}{(1)}
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131 \lineiii{<>}{not equal}{(1)}
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132 \lineiii{is}{object identity}{}
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133 \lineiii{is not}{negated object identity}{}
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134 \end{tableiii}
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135 \indexii{operator}{comparison}
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136 \opindex{==} % XXX *All* others have funny characters < ! >
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137 \opindex{is}
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138 \opindex{is not}
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139
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140 \noindent
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141 Notes:
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142
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143 \begin{description}
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144
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145 \item[(1)]
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146 \code{<>} and \code{!=} are alternate spellings for the same operator.
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147 \code{!=} is the preferred spelling; \code{<>} is obsolescent.
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148
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149 \end{description}
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150
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151 Objects of different types, except different numeric types and different string types, never
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152 compare equal; such objects are ordered consistently but arbitrarily
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153 (so that sorting a heterogeneous array yields a consistent result).
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154 Furthermore, some types (for example, file objects) support only a
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155 degenerate notion of comparison where any two objects of that type are
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156 unequal. Again, such objects are ordered arbitrarily but
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157 consistently. The \code{<}, \code{<=}, \code{>} and \code{>=}
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158 operators will raise a \exception{TypeError} exception when any operand
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159 is a complex number.
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160 \indexii{object}{numeric}
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161 \indexii{objects}{comparing}
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162
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163 Instances of a class normally compare as non-equal unless the class
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164 \withsubitem{(instance method)}{\ttindex{__cmp__()}}
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165 defines the \method{__cmp__()} method. Refer to the
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166 \citetitle[../ref/customization.html]{Python Reference Manual} for
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167 information on the use of this method to effect object comparisons.
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168
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169 \strong{Implementation note:} Objects of different types except
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170 numbers are ordered by their type names; objects of the same types
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171 that don't support proper comparison are ordered by their address.
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172
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173 Two more operations with the same syntactic priority,
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174 \samp{in}\opindex{in} and \samp{not in}\opindex{not in}, are supported
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175 only by sequence types (below).
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176
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177
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178 \subsection{Numeric Types ---
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179 \class{int}, \class{float}, \class{long}, \class{complex}
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180 \label{typesnumeric}}
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181
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182 There are four distinct numeric types: \dfn{plain integers},
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183 \dfn{long integers},
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184 \dfn{floating point numbers}, and \dfn{complex numbers}.
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185 In addition, Booleans are a subtype of plain integers.
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186 Plain integers (also just called \dfn{integers})
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187 are implemented using \ctype{long} in C, which gives them at least 32
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188 bits of precision. Long integers have unlimited precision. Floating
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189 point numbers are implemented using \ctype{double} in C. All bets on
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190 their precision are off unless you happen to know the machine you are
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191 working with.
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192 \obindex{numeric}
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193 \obindex{Boolean}
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194 \obindex{integer}
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195 \obindex{long integer}
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196 \obindex{floating point}
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197 \obindex{complex number}
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198 \indexii{C}{language}
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199
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200 Complex numbers have a real and imaginary part, which are each
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201 implemented using \ctype{double} in C. To extract these parts from
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202 a complex number \var{z}, use \code{\var{z}.real} and \code{\var{z}.imag}.
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203
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204 Numbers are created by numeric literals or as the result of built-in
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205 functions and operators. Unadorned integer literals (including hex
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206 and octal numbers) yield plain integers unless the value they denote
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207 is too large to be represented as a plain integer, in which case
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208 they yield a long integer. Integer literals with an
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209 \character{L} or \character{l} suffix yield long integers
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210 (\character{L} is preferred because \samp{1l} looks too much like
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211 eleven!). Numeric literals containing a decimal point or an exponent
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212 sign yield floating point numbers. Appending \character{j} or
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213 \character{J} to a numeric literal yields a complex number with a
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214 zero real part. A complex numeric literal is the sum of a real and
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215 an imaginary part.
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216 \indexii{numeric}{literals}
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217 \indexii{integer}{literals}
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218 \indexiii{long}{integer}{literals}
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219 \indexii{floating point}{literals}
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220 \indexii{complex number}{literals}
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221 \indexii{hexadecimal}{literals}
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222 \indexii{octal}{literals}
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223
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224 Python fully supports mixed arithmetic: when a binary arithmetic
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225 operator has operands of different numeric types, the operand with the
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226 ``narrower'' type is widened to that of the other, where plain
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227 integer is narrower than long integer is narrower than floating point is
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228 narrower than complex.
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229 Comparisons between numbers of mixed type use the same rule.\footnote{
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230 As a consequence, the list \code{[1, 2]} is considered equal
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231 to \code{[1.0, 2.0]}, and similarly for tuples.
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232 } The constructors \function{int()}, \function{long()}, \function{float()},
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233 and \function{complex()} can be used
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234 to produce numbers of a specific type.
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235 \index{arithmetic}
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236 \bifuncindex{int}
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237 \bifuncindex{long}
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238 \bifuncindex{float}
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239 \bifuncindex{complex}
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240
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241 All numeric types (except complex) support the following operations,
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242 sorted by ascending priority (operations in the same box have the same
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243 priority; all numeric operations have a higher priority than
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244 comparison operations):
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245
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246 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
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247 \lineiii{\var{x} + \var{y}}{sum of \var{x} and \var{y}}{}
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248 \lineiii{\var{x} - \var{y}}{difference of \var{x} and \var{y}}{}
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249 \hline
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250 \lineiii{\var{x} * \var{y}}{product of \var{x} and \var{y}}{}
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251 \lineiii{\var{x} / \var{y}}{quotient of \var{x} and \var{y}}{(1)}
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252 \lineiii{\var{x} \%{} \var{y}}{remainder of \code{\var{x} / \var{y}}}{(4)}
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253 \hline
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254 \lineiii{-\var{x}}{\var{x} negated}{}
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255 \lineiii{+\var{x}}{\var{x} unchanged}{}
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256 \hline
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257 \lineiii{abs(\var{x})}{absolute value or magnitude of \var{x}}{}
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258 \lineiii{int(\var{x})}{\var{x} converted to integer}{(2)}
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259 \lineiii{long(\var{x})}{\var{x} converted to long integer}{(2)}
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260 \lineiii{float(\var{x})}{\var{x} converted to floating point}{}
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261 \lineiii{complex(\var{re},\var{im})}{a complex number with real part \var{re}, imaginary part \var{im}. \var{im} defaults to zero.}{}
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262 \lineiii{\var{c}.conjugate()}{conjugate of the complex number \var{c}}{}
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263 \lineiii{divmod(\var{x}, \var{y})}{the pair \code{(\var{x} // \var{y}, \var{x} \%{} \var{y})}}{(3)(4)}
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264 \lineiii{pow(\var{x}, \var{y})}{\var{x} to the power \var{y}}{}
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265 \lineiii{\var{x} ** \var{y}}{\var{x} to the power \var{y}}{}
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266 \end{tableiii}
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267 \indexiii{operations on}{numeric}{types}
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268 \withsubitem{(complex number method)}{\ttindex{conjugate()}}
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269
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270 \noindent
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271 Notes:
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272 \begin{description}
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273
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274 \item[(1)]
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275 For (plain or long) integer division, the result is an integer.
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276 The result is always rounded towards minus infinity: 1/2 is 0,
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277 (-1)/2 is -1, 1/(-2) is -1, and (-1)/(-2) is 0. Note that the result
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278 is a long integer if either operand is a long integer, regardless of
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279 the numeric value.
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280 \indexii{integer}{division}
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281 \indexiii{long}{integer}{division}
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282
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283 \item[(2)]
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284 Conversion from floating point to (long or plain) integer may round or
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285 truncate as in C; see functions \function{floor()} and
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286 \function{ceil()} in the \refmodule{math}\refbimodindex{math} module
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287 for well-defined conversions.
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288 \withsubitem{(in module math)}{\ttindex{floor()}\ttindex{ceil()}}
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289 \indexii{numeric}{conversions}
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290 \indexii{C}{language}
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291
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292 \item[(3)]
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293 See section \ref{built-in-funcs}, ``Built-in Functions,'' for a full
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294 description.
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295
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296 \item[(4)]
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297 Complex floor division operator, modulo operator, and \function{divmod()}.
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298
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299 \deprecated{2.3}{Instead convert to float using \function{abs()}
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300 if appropriate.}
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301
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302 \end{description}
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303 % XXXJH exceptions: overflow (when? what operations?) zerodivision
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304
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305 \subsubsection{Bit-string Operations on Integer Types \label{bitstring-ops}}
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306 \nodename{Bit-string Operations}
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307
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308 Plain and long integer types support additional operations that make
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309 sense only for bit-strings. Negative numbers are treated as their 2's
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310 complement value (for long integers, this assumes a sufficiently large
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311 number of bits that no overflow occurs during the operation).
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312
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313 The priorities of the binary bit-wise operations are all lower than
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314 the numeric operations and higher than the comparisons; the unary
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315 operation \samp{\~} has the same priority as the other unary numeric
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316 operations (\samp{+} and \samp{-}).
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317
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318 This table lists the bit-string operations sorted in ascending
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319 priority (operations in the same box have the same priority):
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320
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321 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
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322 \lineiii{\var{x} | \var{y}}{bitwise \dfn{or} of \var{x} and \var{y}}{}
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323 \lineiii{\var{x} \^{} \var{y}}{bitwise \dfn{exclusive or} of \var{x} and \var{y}}{}
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324 \lineiii{\var{x} \&{} \var{y}}{bitwise \dfn{and} of \var{x} and \var{y}}{}
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325 % The empty groups below prevent conversion to guillemets.
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326 \lineiii{\var{x} <{}< \var{n}}{\var{x} shifted left by \var{n} bits}{(1), (2)}
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327 \lineiii{\var{x} >{}> \var{n}}{\var{x} shifted right by \var{n} bits}{(1), (3)}
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328 \hline
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329 \lineiii{\~\var{x}}{the bits of \var{x} inverted}{}
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330 \end{tableiii}
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331 \indexiii{operations on}{integer}{types}
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332 \indexii{bit-string}{operations}
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333 \indexii{shifting}{operations}
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334 \indexii{masking}{operations}
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335
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336 \noindent
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337 Notes:
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338 \begin{description}
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339 \item[(1)] Negative shift counts are illegal and cause a
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340 \exception{ValueError} to be raised.
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341 \item[(2)] A left shift by \var{n} bits is equivalent to
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342 multiplication by \code{pow(2, \var{n})} without overflow check.
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343 \item[(3)] A right shift by \var{n} bits is equivalent to
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344 division by \code{pow(2, \var{n})} without overflow check.
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345 \end{description}
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346
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347
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348 \subsection{Iterator Types \label{typeiter}}
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349
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350 \versionadded{2.2}
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351 \index{iterator protocol}
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352 \index{protocol!iterator}
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353 \index{sequence!iteration}
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354 \index{container!iteration over}
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355
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356 Python supports a concept of iteration over containers. This is
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357 implemented using two distinct methods; these are used to allow
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358 user-defined classes to support iteration. Sequences, described below
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359 in more detail, always support the iteration methods.
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360
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361 One method needs to be defined for container objects to provide
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362 iteration support:
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363
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364 \begin{methoddesc}[container]{__iter__}{}
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365 Return an iterator object. The object is required to support the
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366 iterator protocol described below. If a container supports
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367 different types of iteration, additional methods can be provided to
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368 specifically request iterators for those iteration types. (An
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369 example of an object supporting multiple forms of iteration would be
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370 a tree structure which supports both breadth-first and depth-first
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371 traversal.) This method corresponds to the \member{tp_iter} slot of
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372 the type structure for Python objects in the Python/C API.
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373 \end{methoddesc}
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374
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375 The iterator objects themselves are required to support the following
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376 two methods, which together form the \dfn{iterator protocol}:
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377
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378 \begin{methoddesc}[iterator]{__iter__}{}
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379 Return the iterator object itself. This is required to allow both
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380 containers and iterators to be used with the \keyword{for} and
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381 \keyword{in} statements. This method corresponds to the
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382 \member{tp_iter} slot of the type structure for Python objects in
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383 the Python/C API.
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384 \end{methoddesc}
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385
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386 \begin{methoddesc}[iterator]{next}{}
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387 Return the next item from the container. If there are no further
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388 items, raise the \exception{StopIteration} exception. This method
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389 corresponds to the \member{tp_iternext} slot of the type structure
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390 for Python objects in the Python/C API.
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391 \end{methoddesc}
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392
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393 Python defines several iterator objects to support iteration over
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394 general and specific sequence types, dictionaries, and other more
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395 specialized forms. The specific types are not important beyond their
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396 implementation of the iterator protocol.
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397
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398 The intention of the protocol is that once an iterator's
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399 \method{next()} method raises \exception{StopIteration}, it will
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400 continue to do so on subsequent calls. Implementations that
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401 do not obey this property are deemed broken. (This constraint
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402 was added in Python 2.3; in Python 2.2, various iterators are
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parents: 24227
diff changeset
403 broken according to this rule.)
62f4b45b05fd Record the decision that StopIteration is a sink state (see recent
Guido van Rossum <guido@python.org>
parents: 24227
diff changeset
404
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Raymond Hettinger <python@rcn.com>
parents: 29516
diff changeset
405 Python's generators provide a convenient way to implement the
8807e901c526 SF bug #696777: How to make a class iterable using a member generator.
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parents: 29516
diff changeset
406 iterator protocol. If a container object's \method{__iter__()}
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parents: 29516
diff changeset
407 method is implemented as a generator, it will automatically
8807e901c526 SF bug #696777: How to make a class iterable using a member generator.
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parents: 29516
diff changeset
408 return an iterator object (technically, a generator object)
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parents: 29516
diff changeset
409 supplying the \method{__iter__()} and \method{next()} methods.
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parents: 29516
diff changeset
410
17658
d6498b1ef50d Added section describing the iterator protocol.
Fred Drake <fdrake@acm.org>
parents: 17616
diff changeset
411
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Raymond Hettinger <python@rcn.com>
parents: 34975
diff changeset
412 \subsection{Sequence Types ---
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Raymond Hettinger <python@rcn.com>
parents: 34975
diff changeset
413 \class{str}, \class{unicode}, \class{list},
f89cbe69db63 SF bug #1215887: String and list methods documentation deeply hidden
Raymond Hettinger <python@rcn.com>
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diff changeset
414 \class{tuple}, \class{buffer}, \class{xrange}
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parents: 34975
diff changeset
415 \label{typesseq}}
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416
13967
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach
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diff changeset
417 There are six sequence types: strings, Unicode strings, lists,
14044
a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange()
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parents: 13967
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418 tuples, buffers, and xrange objects.
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419
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Steve Holden <steve@holdenweb.com>
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diff changeset
420 String literals are written in single or double quotes:
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parents: 11463
diff changeset
421 \code{'xyzzy'}, \code{"frobozz"}. See chapter 2 of the
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parents: 13894
diff changeset
422 \citetitle[../ref/strings.html]{Python Reference Manual} for more about
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
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parents: 13894
diff changeset
423 string literals. Unicode strings are much like strings, but are
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67f2190e1f6d SF Patch #1093896: miscellaneous doc typos
Raymond Hettinger <python@rcn.com>
parents: 34078
diff changeset
424 specified in the syntax using a preceding \character{u} character:
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Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
425 \code{u'abc'}, \code{u"def"}. Lists are constructed with square brackets,
11463
17e12305973e Use \citetitle and \programopt as appropriate.
Fred Drake <fdrake@acm.org>
parents: 11183
diff changeset
426 separating items with commas: \code{[a, b, c]}. Tuples are
17e12305973e Use \citetitle and \programopt as appropriate.
Fred Drake <fdrake@acm.org>
parents: 11183
diff changeset
427 constructed by the comma operator (not within square brackets), with
17e12305973e Use \citetitle and \programopt as appropriate.
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parents: 11183
diff changeset
428 or without enclosing parentheses, but an empty tuple must have the
30375
4aa84a8b1fe4 Fix spacing markup and other sundries.
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parents: 30250
diff changeset
429 enclosing parentheses, such as \code{a, b, c} or \code{()}. A single
4aa84a8b1fe4 Fix spacing markup and other sundries.
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parents: 30250
diff changeset
430 item tuple must have a trailing comma, such as \code{(d,)}.
15005
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is
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431 \obindex{sequence}
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432 \obindex{string}
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433 \obindex{Unicode}
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diff changeset
434 \obindex{tuple}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is
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parents: 14710
diff changeset
435 \obindex{list}
18395
1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
parents: 18391
diff changeset
436
1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
parents: 18391
diff changeset
437 Buffer objects are not directly supported by Python syntax, but can be
1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
parents: 18391
diff changeset
438 created by calling the builtin function
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f559e97a41be Remove spurious period.
Fred Drake <fdrake@acm.org>
parents: 24902
diff changeset
439 \function{buffer()}.\bifuncindex{buffer} They don't support
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63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
440 concatenation or repetition.
18395
1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
parents: 18391
diff changeset
441 \obindex{buffer}
1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
parents: 18391
diff changeset
442
1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
parents: 18391
diff changeset
443 Xrange objects are similar to buffers in that there is no specific
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63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
444 syntax to create them, but they are created using the \function{xrange()}
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
445 function.\bifuncindex{xrange} They don't support slicing,
63ee31bb25f3 Make a start at describing the results of class/type unification
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parents: 23847
diff changeset
446 concatenation or repetition, and using \code{in}, \code{not in},
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
447 \function{min()} or \function{max()} on them is inefficient.
15005
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is
Fred Drake <fdrake@acm.org>
parents: 14710
diff changeset
448 \obindex{xrange}
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diff changeset
449
18395
1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
parents: 18391
diff changeset
450 Most sequence types support the following operations. The \samp{in} and
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diff changeset
451 \samp{not in} operations have the same priorities as the comparison
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parents:
diff changeset
452 operations. The \samp{+} and \samp{*} operations have the same
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parents:
diff changeset
453 priority as the corresponding numeric operations.\footnote{They must
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
454 have since the parser can't tell the type of the operands.}
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parents:
diff changeset
455
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parents:
diff changeset
456 This table lists the sequence operations sorted in ascending priority
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diff changeset
457 (operations in the same box have the same priority). In the table,
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diff changeset
458 \var{s} and \var{t} are sequences of the same type; \var{n}, \var{i}
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diff changeset
459 and \var{j} are integers:
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parents:
diff changeset
460
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
461 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
33688
af300403edb8 SF patch #1041364: True/False instead of 1/0 in libstdtypes.tex
Raymond Hettinger <python@rcn.com>
parents: 33448
diff changeset
462 \lineiii{\var{x} in \var{s}}{\code{True} if an item of \var{s} is equal to \var{x}, else \code{False}}{(1)}
af300403edb8 SF patch #1041364: True/False instead of 1/0 in libstdtypes.tex
Raymond Hettinger <python@rcn.com>
parents: 33448
diff changeset
463 \lineiii{\var{x} not in \var{s}}{\code{False} if an item of \var{s} is
af300403edb8 SF patch #1041364: True/False instead of 1/0 in libstdtypes.tex
Raymond Hettinger <python@rcn.com>
parents: 33448
diff changeset
464 equal to \var{x}, else \code{True}}{(1)}
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diff changeset
465 \hline
32974
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
466 \lineiii{\var{s} + \var{t}}{the concatenation of \var{s} and \var{t}}{(6)}
24598
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a
Barry Warsaw <barry@python.org>
parents: 24459
diff changeset
467 \lineiii{\var{s} * \var{n}\textrm{,} \var{n} * \var{s}}{\var{n} shallow copies of \var{s} concatenated}{(2)}
8730
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diff changeset
468 \hline
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12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a
Barry Warsaw <barry@python.org>
parents: 24459
diff changeset
469 \lineiii{\var{s}[\var{i}]}{\var{i}'th item of \var{s}, origin 0}{(3)}
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a
Barry Warsaw <barry@python.org>
parents: 24459
diff changeset
470 \lineiii{\var{s}[\var{i}:\var{j}]}{slice of \var{s} from \var{i} to \var{j}}{(3), (4)}
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24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
471 \lineiii{\var{s}[\var{i}:\var{j}:\var{k}]}{slice of \var{s} from \var{i} to \var{j} with step \var{k}}{(3), (5)}
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diff changeset
472 \hline
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diff changeset
473 \lineiii{len(\var{s})}{length of \var{s}}{}
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diff changeset
474 \lineiii{min(\var{s})}{smallest item of \var{s}}{}
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parents:
diff changeset
475 \lineiii{max(\var{s})}{largest item of \var{s}}{}
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diff changeset
476 \end{tableiii}
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diff changeset
477 \indexiii{operations on}{sequence}{types}
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diff changeset
478 \bifuncindex{len}
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diff changeset
479 \bifuncindex{min}
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diff changeset
480 \bifuncindex{max}
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diff changeset
481 \indexii{concatenation}{operation}
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diff changeset
482 \indexii{repetition}{operation}
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parents:
diff changeset
483 \indexii{subscript}{operation}
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diff changeset
484 \indexii{slice}{operation}
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
485 \indexii{extended slice}{operation}
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diff changeset
486 \opindex{in}
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diff changeset
487 \opindex{not in}
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parents:
diff changeset
488
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diff changeset
489 \noindent
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diff changeset
490 Notes:
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parents:
diff changeset
491
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diff changeset
492 \begin{description}
24598
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parents: 24459
diff changeset
493 \item[(1)] When \var{s} is a string or Unicode string object the
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a
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parents: 24459
diff changeset
494 \code{in} and \code{not in} operations act like a substring test. In
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a
Barry Warsaw <barry@python.org>
parents: 24459
diff changeset
495 Python versions before 2.3, \var{x} had to be a string of length 1.
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a
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parents: 24459
diff changeset
496 In Python 2.3 and beyond, \var{x} may be a string of any length.
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parents: 24459
diff changeset
497
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a
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parents: 24459
diff changeset
498 \item[(2)] Values of \var{n} less than \code{0} are treated as
12223
e82e82b3b9ad Merged changes from the 1.5.2p2 release.
Fred Drake <fdrake@acm.org>
parents: 11463
diff changeset
499 \code{0} (which yields an empty sequence of the same type as
19529
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
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parents: 19243
diff changeset
500 \var{s}). Note also that the copies are shallow; nested structures
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
501 are not copied. This often haunts new Python programmers; consider:
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
502
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
503 \begin{verbatim}
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
504 >>> lists = [[]] * 3
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
505 >>> lists
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
506 [[], [], []]
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
507 >>> lists[0].append(3)
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
508 >>> lists
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
509 [[3], [3], [3]]
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
510 \end{verbatim}
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
511
33899
eb979c3f14ba Mistakes in the "sequence types" page:
Armin Rigo <arigo@tunes.org>
parents: 33688
diff changeset
512 What has happened is that \code{[[]]} is a one-element list containing
eb979c3f14ba Mistakes in the "sequence types" page:
Armin Rigo <arigo@tunes.org>
parents: 33688
diff changeset
513 an empty list, so all three elements of \code{[[]] * 3} are (pointers to)
eb979c3f14ba Mistakes in the "sequence types" page:
Armin Rigo <arigo@tunes.org>
parents: 33688
diff changeset
514 this single empty list. Modifying any of the elements of \code{lists}
eb979c3f14ba Mistakes in the "sequence types" page:
Armin Rigo <arigo@tunes.org>
parents: 33688
diff changeset
515 modifies this single list. You can create a list of different lists this
eb979c3f14ba Mistakes in the "sequence types" page:
Armin Rigo <arigo@tunes.org>
parents: 33688
diff changeset
516 way:
19529
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parents: 19243
diff changeset
517
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
518 \begin{verbatim}
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Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
519 >>> lists = [[] for i in range(3)]
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Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
520 >>> lists[0].append(3)
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
521 >>> lists[1].append(5)
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
522 >>> lists[2].append(7)
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
523 >>> lists
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
524 [[3], [5], [7]]
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
525 \end{verbatim}
12223
e82e82b3b9ad Merged changes from the 1.5.2p2 release.
Fred Drake <fdrake@acm.org>
parents: 11463
diff changeset
526
24598
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parents: 24459
diff changeset
527 \item[(3)] If \var{i} or \var{j} is negative, the index is relative to
18416
33b4357aebb8 Fix up a few style nits -- avoid "e.g." and "i.e." -- these make
Fred Drake <fdrake@acm.org>
parents: 18395
diff changeset
528 the end of the string: \code{len(\var{s}) + \var{i}} or
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parents:
diff changeset
529 \code{len(\var{s}) + \var{j}} is substituted. But note that \code{-0} is
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
530 still \code{0}.
22241
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
531
24598
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a
Barry Warsaw <barry@python.org>
parents: 24459
diff changeset
532 \item[(4)] The slice of \var{s} from \var{i} to \var{j} is defined as
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
533 the sequence of items with index \var{k} such that \code{\var{i} <=
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
534 \var{k} < \var{j}}. If \var{i} or \var{j} is greater than
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
535 \code{len(\var{s})}, use \code{len(\var{s})}. If \var{i} is omitted,
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
536 use \code{0}. If \var{j} is omitted, use \code{len(\var{s})}. If
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
537 \var{i} is greater than or equal to \var{j}, the slice is empty.
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
538
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
539 \item[(5)] The slice of \var{s} from \var{i} to \var{j} with step
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
540 \var{k} is defined as the sequence of items with index
33899
eb979c3f14ba Mistakes in the "sequence types" page:
Armin Rigo <arigo@tunes.org>
parents: 33688
diff changeset
541 \code{\var{x} = \var{i} + \var{n}*\var{k}} such that
eb979c3f14ba Mistakes in the "sequence types" page:
Armin Rigo <arigo@tunes.org>
parents: 33688
diff changeset
542 $0 \leq n < \frac{j-i}{k}$. In other words, the indices
eb979c3f14ba Mistakes in the "sequence types" page:
Armin Rigo <arigo@tunes.org>
parents: 33688
diff changeset
543 are \code{i}, \code{i+k}, \code{i+2*k}, \code{i+3*k} and so on, stopping when
eb979c3f14ba Mistakes in the "sequence types" page:
Armin Rigo <arigo@tunes.org>
parents: 33688
diff changeset
544 \var{j} is reached (but never including \var{j}). If \var{i} or \var{j}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
545 is greater than \code{len(\var{s})}, use \code{len(\var{s})}. If
30250
830c0cd8fdb2 SF patch #797180: Bug 792656: slicing explained
Raymond Hettinger <python@rcn.com>
parents: 30095
diff changeset
546 \var{i} or \var{j} are omitted then they become ``end'' values
830c0cd8fdb2 SF patch #797180: Bug 792656: slicing explained
Raymond Hettinger <python@rcn.com>
parents: 30095
diff changeset
547 (which end depends on the sign of \var{k}). Note, \var{k} cannot
830c0cd8fdb2 SF patch #797180: Bug 792656: slicing explained
Raymond Hettinger <python@rcn.com>
parents: 30095
diff changeset
548 be zero.
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
549
32974
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
550 \item[(6)] If \var{s} and \var{t} are both strings, some Python
32975
9b188158181f Typo fix; use 'in-place' instead of 'inplace'
Andrew M. Kuchling <amk@amk.ca>
parents: 32974
diff changeset
551 implementations such as CPython can usually perform an in-place optimization
32974
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
552 for assignments of the form \code{\var{s}=\var{s}+\var{t}} or
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
553 \code{\var{s}+=\var{t}}. When applicable, this optimization makes
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
554 quadratic run-time much less likely. This optimization is both version
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
555 and implementation dependent. For performance sensitive code, it is
34296
67f2190e1f6d SF Patch #1093896: miscellaneous doc typos
Raymond Hettinger <python@rcn.com>
parents: 34078
diff changeset
556 preferable to use the \method{str.join()} method which assures consistent
32974
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
557 linear concatenation performance across versions and implementations.
32975
9b188158181f Typo fix; use 'in-place' instead of 'inplace'
Andrew M. Kuchling <amk@amk.ca>
parents: 32974
diff changeset
558 \versionchanged[Formerly, string concatenation never occurred in-place]{2.4}
32974
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
559
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
560 \end{description}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
561
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
562
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
563 \subsubsection{String Methods \label{string-methods}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
564
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
565 These are the string methods which both 8-bit strings and Unicode
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
566 objects support:
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
567
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
568 \begin{methoddesc}[string]{capitalize}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
569 Return a copy of the string with only its first character capitalized.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
570
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
571 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
572 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
573
31021
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
574 \begin{methoddesc}[string]{center}{width\optional{, fillchar}}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
575 Return centered in a string of length \var{width}. Padding is done
31021
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
576 using the specified \var{fillchar} (default is a space).
31022
845f19b145a8 Add version changed doc for addition of fillchar to ljust/rjust/center
Neal Norwitz <nnorwitz@gmail.com>
parents: 31021
diff changeset
577 \versionchanged[Support for the \var{fillchar} argument]{2.4}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
578 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
579
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
580 \begin{methoddesc}[string]{count}{sub\optional{, start\optional{, end}}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
581 Return the number of occurrences of substring \var{sub} in string
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
582 S\code{[\var{start}:\var{end}]}. Optional arguments \var{start} and
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
583 \var{end} are interpreted as in slice notation.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
584 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
585
21332
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
586 \begin{methoddesc}[string]{decode}{\optional{encoding\optional{, errors}}}
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
587 Decodes the string using the codec registered for \var{encoding}.
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
588 \var{encoding} defaults to the default string encoding. \var{errors}
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
589 may be given to set a different error handling scheme. The default is
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
590 \code{'strict'}, meaning that encoding errors raise
32459
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
591 \exception{UnicodeError}. Other possible values are \code{'ignore'},
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
592 \code{'replace'} and any other name registered via
35952
48353cf51340 Backport checkin:
Walter Dörwald <walter@livinglogic.de>
parents: 35687
diff changeset
593 \function{codecs.register_error}, see section~\ref{codec-base-classes}.
21332
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
594 \versionadded{2.2}
32459
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
595 \versionchanged[Support for other error handling schemes added]{2.3}
21332
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
596 \end{methoddesc}
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
597
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
598 \begin{methoddesc}[string]{encode}{\optional{encoding\optional{,errors}}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
599 Return an encoded version of the string. Default encoding is the current
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
600 default string encoding. \var{errors} may be given to set a different
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
601 error handling scheme. The default for \var{errors} is
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
602 \code{'strict'}, meaning that encoding errors raise a
32459
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
603 \exception{UnicodeError}. Other possible values are \code{'ignore'},
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
604 \code{'replace'}, \code{'xmlcharrefreplace'}, \code{'backslashreplace'}
35952
48353cf51340 Backport checkin:
Walter Dörwald <walter@livinglogic.de>
parents: 35687
diff changeset
605 and any other name registered via \function{codecs.register_error},
48353cf51340 Backport checkin:
Walter Dörwald <walter@livinglogic.de>
parents: 35687
diff changeset
606 see section~\ref{codec-base-classes}.
32459
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
607 For a list of possible encodings, see section~\ref{standard-encodings}.
15332
12aec3381c94 Marc-Andre Lemburg <mal@lemburg.com> noted that the encode() string method
Fred Drake <fdrake@acm.org>
parents: 15005
diff changeset
608 \versionadded{2.0}
32459
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
609 \versionchanged[Support for \code{'xmlcharrefreplace'} and
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
610 \code{'backslashreplace'} and other error handling schemes added]{2.3}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
611 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
612
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
613 \begin{methoddesc}[string]{endswith}{suffix\optional{, start\optional{, end}}}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
614 Return \code{True} if the string ends with the specified \var{suffix},
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
615 otherwise return \code{False}. With optional \var{start}, test beginning at
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
616 that position. With optional \var{end}, stop comparing at that position.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
617 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
618
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
619 \begin{methoddesc}[string]{expandtabs}{\optional{tabsize}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
620 Return a copy of the string where all tab characters are expanded
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
621 using spaces. If \var{tabsize} is not given, a tab size of \code{8}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
622 characters is assumed.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
623 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
624
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
625 \begin{methoddesc}[string]{find}{sub\optional{, start\optional{, end}}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
626 Return the lowest index in the string where substring \var{sub} is
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
627 found, such that \var{sub} is contained in the range [\var{start},
36334
98faac1df5bb Bug #1396471: Document that Windows' ftell() can return invalid
Georg Brandl <georg@python.org>
parents: 36167
diff changeset
628 \var{end}]. Optional arguments \var{start} and \var{end} are
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
629 interpreted as in slice notation. Return \code{-1} if \var{sub} is
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
630 not found.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
631 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
632
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
633 \begin{methoddesc}[string]{index}{sub\optional{, start\optional{, end}}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
634 Like \method{find()}, but raise \exception{ValueError} when the
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
635 substring is not found.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
636 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
637
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
638 \begin{methoddesc}[string]{isalnum}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
639 Return true if all characters in the string are alphanumeric and there
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
640 is at least one character, false otherwise.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
641
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
642 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
643 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
644
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
645 \begin{methoddesc}[string]{isalpha}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
646 Return true if all characters in the string are alphabetic and there
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
647 is at least one character, false otherwise.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
648
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
649 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
650 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
651
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
652 \begin{methoddesc}[string]{isdigit}{}
30707
9e21e56bf5f3 Patch #825679: Clarify semantics of .isfoo on empty strings.
Martin v. Löwis <martin@v.loewis.de>
parents: 30705
diff changeset
653 Return true if all characters in the string are digits and there
9e21e56bf5f3 Patch #825679: Clarify semantics of .isfoo on empty strings.
Martin v. Löwis <martin@v.loewis.de>
parents: 30705
diff changeset
654 is at least one character, false otherwise.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
655
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
656 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
657 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
658
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
659 \begin{methoddesc}[string]{islower}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
660 Return true if all cased characters in the string are lowercase and
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
661 there is at least one cased character, false otherwise.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
662
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
663 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
664 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
665
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
666 \begin{methoddesc}[string]{isspace}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
667 Return true if there are only whitespace characters in the string and
30707
9e21e56bf5f3 Patch #825679: Clarify semantics of .isfoo on empty strings.
Martin v. Löwis <martin@v.loewis.de>
parents: 30705
diff changeset
668 there is at least one character, false otherwise.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
669
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
670 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
671 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
672
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
673 \begin{methoddesc}[string]{istitle}{}
30707
9e21e56bf5f3 Patch #825679: Clarify semantics of .isfoo on empty strings.
Martin v. Löwis <martin@v.loewis.de>
parents: 30705
diff changeset
674 Return true if the string is a titlecased string and there is at least one
30810
2cba0de70df6 Add list.sorted() classmethod.
Raymond Hettinger <python@rcn.com>
parents: 30750
diff changeset
675 character, for example uppercase characters may only follow uncased
30707
9e21e56bf5f3 Patch #825679: Clarify semantics of .isfoo on empty strings.
Martin v. Löwis <martin@v.loewis.de>
parents: 30705
diff changeset
676 characters and lowercase characters only cased ones. Return false
9e21e56bf5f3 Patch #825679: Clarify semantics of .isfoo on empty strings.
Martin v. Löwis <martin@v.loewis.de>
parents: 30705
diff changeset
677 otherwise.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
678
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
679 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
680 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
681
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
682 \begin{methoddesc}[string]{isupper}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
683 Return true if all cased characters in the string are uppercase and
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
684 there is at least one cased character, false otherwise.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
685
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
686 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
687 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
688
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
689 \begin{methoddesc}[string]{join}{seq}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
690 Return a string which is the concatenation of the strings in the
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
691 sequence \var{seq}. The separator between elements is the string
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
692 providing this method.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
693 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
694
31021
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
695 \begin{methoddesc}[string]{ljust}{width\optional{, fillchar}}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
696 Return the string left justified in a string of length \var{width}.
31021
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
697 Padding is done using the specified \var{fillchar} (default is a
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
698 space). The original string is returned if
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
699 \var{width} is less than \code{len(\var{s})}.
31022
845f19b145a8 Add version changed doc for addition of fillchar to ljust/rjust/center
Neal Norwitz <nnorwitz@gmail.com>
parents: 31021
diff changeset
700 \versionchanged[Support for the \var{fillchar} argument]{2.4}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
701 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
702
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
703 \begin{methoddesc}[string]{lower}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
704 Return a copy of the string converted to lowercase.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
705
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
706 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
707 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
708
23017
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
709 \begin{methoddesc}[string]{lstrip}{\optional{chars}}
34975
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
710 Return a copy of the string with leading characters removed. The
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
711 \var{chars} argument is a string specifying the set of characters
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
712 to be removed. If omitted or \code{None}, the \var{chars} argument
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
713 defaults to removing whitespace. The \var{chars} argument is not
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
714 a prefix; rather, all combinations of its values are stripped:
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
715 \begin{verbatim}
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
716 >>> ' spacious '.lstrip()
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
717 'spacious '
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
718 >>> 'www.example.com'.lstrip('cmowz.')
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
719 'example.com'
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
720 \end{verbatim}
26259
60d809a25bae Document that a minor feature was added in 2.2.2. ;-(
Fred Drake <fdrake@acm.org>
parents: 26161
diff changeset
721 \versionchanged[Support for the \var{chars} argument]{2.2.2}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
722 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
723
30750
1d92ecdf2bb1 Avoid confusing name for the 3rd argument to str.replace().
Fred Drake <fdrake@acm.org>
parents: 30737
diff changeset
724 \begin{methoddesc}[string]{replace}{old, new\optional{, count}}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
725 Return a copy of the string with all occurrences of substring
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
726 \var{old} replaced by \var{new}. If the optional argument
30750
1d92ecdf2bb1 Avoid confusing name for the 3rd argument to str.replace().
Fred Drake <fdrake@acm.org>
parents: 30737
diff changeset
727 \var{count} is given, only the first \var{count} occurrences are
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
728 replaced.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
729 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
730
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
731 \begin{methoddesc}[string]{rfind}{sub \optional{,start \optional{,end}}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
732 Return the highest index in the string where substring \var{sub} is
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
733 found, such that \var{sub} is contained within s[start,end]. Optional
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
734 arguments \var{start} and \var{end} are interpreted as in slice
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
735 notation. Return \code{-1} on failure.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
736 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
737
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
738 \begin{methoddesc}[string]{rindex}{sub\optional{, start\optional{, end}}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
739 Like \method{rfind()} but raises \exception{ValueError} when the
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
740 substring \var{sub} is not found.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
741 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
742
31021
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
743 \begin{methoddesc}[string]{rjust}{width\optional{, fillchar}}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
744 Return the string right justified in a string of length \var{width}.
31021
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
745 Padding is done using the specified \var{fillchar} (default is a space).
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
746 The original string is returned if
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
747 \var{width} is less than \code{len(\var{s})}.
31022
845f19b145a8 Add version changed doc for addition of fillchar to ljust/rjust/center
Neal Norwitz <nnorwitz@gmail.com>
parents: 31021
diff changeset
748 \versionchanged[Support for the \var{fillchar} argument]{2.4}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
749 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
750
31206
3771ff99d5f2 Update documentations for str.rsplit() with Alex Martelli's rewrite.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31199
diff changeset
751 \begin{methoddesc}[string]{rsplit}{\optional{sep \optional{,maxsplit}}}
3771ff99d5f2 Update documentations for str.rsplit() with Alex Martelli's rewrite.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31199
diff changeset
752 Return a list of the words in the string, using \var{sep} as the
3771ff99d5f2 Update documentations for str.rsplit() with Alex Martelli's rewrite.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31199
diff changeset
753 delimiter string. If \var{maxsplit} is given, at most \var{maxsplit}
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
754 splits are done, the \emph{rightmost} ones. If \var{sep} is not specified
34491
68020bd1b9e2 SF bug #1105286: Undocumented implicit strip() in split(None) string method
Raymond Hettinger <python@rcn.com>
parents: 34296
diff changeset
755 or \code{None}, any whitespace string is a separator. Except for splitting
68020bd1b9e2 SF bug #1105286: Undocumented implicit strip() in split(None) string method
Raymond Hettinger <python@rcn.com>
parents: 34296
diff changeset
756 from the right, \method{rsplit()} behaves like \method{split()} which
68020bd1b9e2 SF bug #1105286: Undocumented implicit strip() in split(None) string method
Raymond Hettinger <python@rcn.com>
parents: 34296
diff changeset
757 is described in detail below.
31199
504943c89193 Add rsplit method for str and unicode builtin types.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31022
diff changeset
758 \versionadded{2.4}
504943c89193 Add rsplit method for str and unicode builtin types.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31022
diff changeset
759 \end{methoddesc}
504943c89193 Add rsplit method for str and unicode builtin types.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31022
diff changeset
760
23017
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
761 \begin{methoddesc}[string]{rstrip}{\optional{chars}}
34975
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
762 Return a copy of the string with trailing characters removed. The
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
763 \var{chars} argument is a string specifying the set of characters
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
764 to be removed. If omitted or \code{None}, the \var{chars} argument
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
765 defaults to removing whitespace. The \var{chars} argument is not
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
766 a suffix; rather, all combinations of its values are stripped:
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
767 \begin{verbatim}
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
768 >>> ' spacious '.rstrip()
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
769 ' spacious'
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
770 >>> 'mississippi'.rstrip('ipz')
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
771 'mississ'
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
772 \end{verbatim}
26259
60d809a25bae Document that a minor feature was added in 2.2.2. ;-(
Fred Drake <fdrake@acm.org>
parents: 26161
diff changeset
773 \versionchanged[Support for the \var{chars} argument]{2.2.2}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
774 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
775
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
776 \begin{methoddesc}[string]{split}{\optional{sep \optional{,maxsplit}}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
777 Return a list of the words in the string, using \var{sep} as the
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
778 delimiter string. If \var{maxsplit} is given, at most \var{maxsplit}
33411
136b388569a0 SF bug #901654: split method documentation can be improved
Raymond Hettinger <python@rcn.com>
parents: 33102
diff changeset
779 splits are done. (thus, the list will have at most \code{\var{maxsplit}+1}
34508
13176ed52e65 SF bug #1108303: fix .split() maxsplit doc
Raymond Hettinger <python@rcn.com>
parents: 34491
diff changeset
780 elements). If \var{maxsplit} is not specified, then there
33411
136b388569a0 SF bug #901654: split method documentation can be improved
Raymond Hettinger <python@rcn.com>
parents: 33102
diff changeset
781 is no limit on the number of splits (all possible splits are made).
136b388569a0 SF bug #901654: split method documentation can be improved
Raymond Hettinger <python@rcn.com>
parents: 33102
diff changeset
782 Consecutive delimiters are not grouped together and are
136b388569a0 SF bug #901654: split method documentation can be improved
Raymond Hettinger <python@rcn.com>
parents: 33102
diff changeset
783 deemed to delimit empty strings (for example, \samp{'1,,2'.split(',')}
33412
c09318b0090d Add missing close parenthesis.
Raymond Hettinger <python@rcn.com>
parents: 33411
diff changeset
784 returns \samp{['1', '', '2']}). The \var{sep} argument may consist of
33411
136b388569a0 SF bug #901654: split method documentation can be improved
Raymond Hettinger <python@rcn.com>
parents: 33102
diff changeset
785 multiple characters (for example, \samp{'1, 2, 3'.split(', ')} returns
33412
c09318b0090d Add missing close parenthesis.
Raymond Hettinger <python@rcn.com>
parents: 33411
diff changeset
786 \samp{['1', '2', '3']}). Splitting an empty string with a specified
34917
6bdc3426d411 Correct swapped descriptions of empty string splits.
Raymond Hettinger <python@rcn.com>
parents: 34898
diff changeset
787 separator returns \samp{['']}.
33411
136b388569a0 SF bug #901654: split method documentation can be improved
Raymond Hettinger <python@rcn.com>
parents: 33102
diff changeset
788
136b388569a0 SF bug #901654: split method documentation can be improved
Raymond Hettinger <python@rcn.com>
parents: 33102
diff changeset
789 If \var{sep} is not specified or is \code{None}, a different splitting
34491
68020bd1b9e2 SF bug #1105286: Undocumented implicit strip() in split(None) string method
Raymond Hettinger <python@rcn.com>
parents: 34296
diff changeset
790 algorithm is applied. First, whitespace characters (spaces, tabs,
68020bd1b9e2 SF bug #1105286: Undocumented implicit strip() in split(None) string method
Raymond Hettinger <python@rcn.com>
parents: 34296
diff changeset
791 newlines, returns, and formfeeds) are stripped from both ends. Then,
68020bd1b9e2 SF bug #1105286: Undocumented implicit strip() in split(None) string method
Raymond Hettinger <python@rcn.com>
parents: 34296
diff changeset
792 words are separated by arbitrary length strings of whitespace
68020bd1b9e2 SF bug #1105286: Undocumented implicit strip() in split(None) string method
Raymond Hettinger <python@rcn.com>
parents: 34296
diff changeset
793 characters. Consecutive whitespace delimiters are treated as a single
68020bd1b9e2 SF bug #1105286: Undocumented implicit strip() in split(None) string method
Raymond Hettinger <python@rcn.com>
parents: 34296
diff changeset
794 delimiter (\samp{'1 2 3'.split()} returns \samp{['1', '2', '3']}).
68020bd1b9e2 SF bug #1105286: Undocumented implicit strip() in split(None) string method
Raymond Hettinger <python@rcn.com>
parents: 34296
diff changeset
795 Splitting an empty string or a string consisting of just whitespace
34917
6bdc3426d411 Correct swapped descriptions of empty string splits.
Raymond Hettinger <python@rcn.com>
parents: 34898
diff changeset
796 returns an empty list.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
797 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
798
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
799 \begin{methoddesc}[string]{splitlines}{\optional{keepends}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
800 Return a list of the lines in the string, breaking at line
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
801 boundaries. Line breaks are not included in the resulting list unless
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
802 \var{keepends} is given and true.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
803 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
804
23017
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
805 \begin{methoddesc}[string]{startswith}{prefix\optional{,
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
806 start\optional{, end}}}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
807 Return \code{True} if string starts with the \var{prefix}, otherwise
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
808 return \code{False}. With optional \var{start}, test string beginning at
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
809 that position. With optional \var{end}, stop comparing string at that
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
810 position.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
811 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
812
23017
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
813 \begin{methoddesc}[string]{strip}{\optional{chars}}
34975
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
814 Return a copy of the string with the leading and trailing characters
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
815 removed. The \var{chars} argument is a string specifying the set of
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
816 characters to be removed. If omitted or \code{None}, the \var{chars}
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
817 argument defaults to removing whitespace. The \var{chars} argument is not
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
818 a prefix or suffix; rather, all combinations of its values are stripped:
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
819 \begin{verbatim}
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
820 >>> ' spacious '.strip()
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
821 'spacious'
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
822 >>> 'www.example.com'.strip('cmowz.')
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
823 'example'
5e511ddef48b SF bug #1202395: Description of string.lstrip() needs improvement
Raymond Hettinger <python@rcn.com>
parents: 34969
diff changeset
824 \end{verbatim}
26259
60d809a25bae Document that a minor feature was added in 2.2.2. ;-(
Fred Drake <fdrake@acm.org>
parents: 26161
diff changeset
825 \versionchanged[Support for the \var{chars} argument]{2.2.2}
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
826 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
827
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
828 \begin{methoddesc}[string]{swapcase}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
829 Return a copy of the string with uppercase characters converted to
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
830 lowercase and vice versa.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
831
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
832 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
833 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
834
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
835 \begin{methoddesc}[string]{title}{}
18416
33b4357aebb8 Fix up a few style nits -- avoid "e.g." and "i.e." -- these make
Fred Drake <fdrake@acm.org>
parents: 18395
diff changeset
836 Return a titlecased version of the string: words start with uppercase
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
837 characters, all remaining cased characters are lowercase.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
838
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
839 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
840 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
841
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
842 \begin{methoddesc}[string]{translate}{table\optional{, deletechars}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
843 Return a copy of the string where all characters occurring in the
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
844 optional argument \var{deletechars} are removed, and the remaining
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
845 characters have been mapped through the given translation table, which
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
846 must be a string of length 256.
29893
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
847
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
848 For Unicode objects, the \method{translate()} method does not
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
849 accept the optional \var{deletechars} argument. Instead, it
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
850 returns a copy of the \var{s} where all characters have been mapped
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
851 through the given translation table which must be a mapping of
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
852 Unicode ordinals to Unicode ordinals, Unicode strings or \code{None}.
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
853 Unmapped characters are left untouched. Characters mapped to \code{None}
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
854 are deleted. Note, a more flexible approach is to create a custom
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
855 character mapping codec using the \refmodule{codecs} module (see
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
856 \module{encodings.cp1251} for an example).
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
857 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
858
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
859 \begin{methoddesc}[string]{upper}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
860 Return a copy of the string converted to uppercase.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
861
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
862 For 8-bit strings, this method is locale-dependent.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
863 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
864
23045
8b1268bc371a Apply the second version of SF patch http://www.python.org/sf/536241
Walter Dörwald <walter@livinglogic.de>
parents: 23017
diff changeset
865 \begin{methoddesc}[string]{zfill}{width}
8b1268bc371a Apply the second version of SF patch http://www.python.org/sf/536241
Walter Dörwald <walter@livinglogic.de>
parents: 23017
diff changeset
866 Return the numeric string left filled with zeros in a string
8b1268bc371a Apply the second version of SF patch http://www.python.org/sf/536241
Walter Dörwald <walter@livinglogic.de>
parents: 23017
diff changeset
867 of length \var{width}. The original string is returned if
8b1268bc371a Apply the second version of SF patch http://www.python.org/sf/536241
Walter Dörwald <walter@livinglogic.de>
parents: 23017
diff changeset
868 \var{width} is less than \code{len(\var{s})}.
26260
b327ffcfe9b7 Better note that str.zfill() was added in 2.2.2 as well. ;-(
Fred Drake <fdrake@acm.org>
parents: 26259
diff changeset
869 \versionadded{2.2.2}
23045
8b1268bc371a Apply the second version of SF patch http://www.python.org/sf/536241
Walter Dörwald <walter@livinglogic.de>
parents: 23017
diff changeset
870 \end{methoddesc}
8b1268bc371a Apply the second version of SF patch http://www.python.org/sf/536241
Walter Dörwald <walter@livinglogic.de>
parents: 23017
diff changeset
871
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
872
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
873 \subsubsection{String Formatting Operations \label{typesseq-strings}}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
874
21177
7d1eac41ce3e Slightly improved indexing for the string-% operator, thanks to comments
Fred Drake <fdrake@acm.org>
parents: 21163
diff changeset
875 \index{formatting, string (\%{})}
21542
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
876 \index{interpolation, string (\%{})}
14552
a8d1c030b19f Add some index entries to make it easier to find information on
Fred Drake <fdrake@acm.org>
parents: 14520
diff changeset
877 \index{string!formatting}
21542
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
878 \index{string!interpolation}
14552
a8d1c030b19f Add some index entries to make it easier to find information on
Fred Drake <fdrake@acm.org>
parents: 14520
diff changeset
879 \index{printf-style formatting}
a8d1c030b19f Add some index entries to make it easier to find information on
Fred Drake <fdrake@acm.org>
parents: 14520
diff changeset
880 \index{sprintf-style formatting}
21177
7d1eac41ce3e Slightly improved indexing for the string-% operator, thanks to comments
Fred Drake <fdrake@acm.org>
parents: 21163
diff changeset
881 \index{\protect\%{} formatting}
21542
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
882 \index{\protect\%{} interpolation}
14552
a8d1c030b19f Add some index entries to make it easier to find information on
Fred Drake <fdrake@acm.org>
parents: 14520
diff changeset
883
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
884 String and Unicode objects have one unique built-in operation: the
21542
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
885 \code{\%} operator (modulo). This is also known as the string
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
886 \emph{formatting} or \emph{interpolation} operator. Given
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
887 \code{\var{format} \% \var{values}} (where \var{format} is a string or
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
888 Unicode object), \code{\%} conversion specifications in \var{format}
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
889 are replaced with zero or more elements of \var{values}. The effect
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
890 is similar to the using \cfunction{sprintf()} in the C language. If
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
891 \var{format} is a Unicode object, or if any of the objects being
5d4135609efc Added index entries similar to some recommended by Skip, and used the word
Fred Drake <fdrake@acm.org>
parents: 21332
diff changeset
892 converted using the \code{\%s} conversion are Unicode objects, the
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
893 result will also be a Unicode object.
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
894
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
895 If \var{format} requires a single argument, \var{values} may be a
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
896 single non-tuple object.\footnote{To format only a tuple you
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
897 should therefore provide a singleton tuple whose only element
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
898 is the tuple to be formatted.} Otherwise, \var{values} must be a tuple with
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
899 exactly the number of items specified by the format string, or a
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
900 single mapping object (for example, a dictionary).
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
901
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
902 A conversion specifier contains two or more characters and has the
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
903 following components, which must occur in this order:
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
904
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
905 \begin{enumerate}
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
906 \item The \character{\%} character, which marks the start of the
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
907 specifier.
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
908 \item Mapping key (optional), consisting of a parenthesised sequence
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
909 of characters (for example, \code{(somename)}).
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
910 \item Conversion flags (optional), which affect the result of some
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
911 conversion types.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
912 \item Minimum field width (optional). If specified as an
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
913 \character{*} (asterisk), the actual width is read from the
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
914 next element of the tuple in \var{values}, and the object to
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
915 convert comes after the minimum field width and optional
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
916 precision.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
917 \item Precision (optional), given as a \character{.} (dot) followed
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
918 by the precision. If specified as \character{*} (an
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
919 asterisk), the actual width is read from the next element of
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
920 the tuple in \var{values}, and the value to convert comes after
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
921 the precision.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
922 \item Length modifier (optional).
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
923 \item Conversion type.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
924 \end{enumerate}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
925
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
926 When the right argument is a dictionary (or other mapping type), then
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
927 the formats in the string \emph{must} include a parenthesised mapping key into
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
928 that dictionary inserted immediately after the \character{\%}
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
929 character. The mapping key selects the value to be formatted from the
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
930 mapping. For example:
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
931
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
932 \begin{verbatim}
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
933 >>> print '%(language)s has %(#)03d quote types.' % \
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
934 {'language': "Python", "#": 2}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
935 Python has 002 quote types.
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
936 \end{verbatim}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
937
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
938 In this case no \code{*} specifiers may occur in a format (since they
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
939 require a sequential parameter list).
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
940
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
941 The conversion flag characters are:
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
942
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
943 \begin{tableii}{c|l}{character}{Flag}{Meaning}
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
944 \lineii{\#}{The value conversion will use the ``alternate form''
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
945 (where defined below).}
27919
4b5c2e025c5e Fix SF bug #687655, String formatting conversions misleading
Neal Norwitz <nnorwitz@gmail.com>
parents: 27225
diff changeset
946 \lineii{0}{The conversion will be zero padded for numeric values.}
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
947 \lineii{-}{The converted value is left adjusted (overrides
25906
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
948 the \character{0} conversion if both are given).}
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
949 \lineii{{~}}{(a space) A blank should be left before a positive number
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
950 (or empty string) produced by a signed conversion.}
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
951 \lineii{+}{A sign character (\character{+} or \character{-}) will
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
952 precede the conversion (overrides a "space" flag).}
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
953 \end{tableii}
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
954
36167
834dd664aefc Bug #1394868: doc typos
Georg Brandl <georg@python.org>
parents: 36136
diff changeset
955 A length modifier (\code{h}, \code{l}, or \code{L}) may be
834dd664aefc Bug #1394868: doc typos
Georg Brandl <georg@python.org>
parents: 36136
diff changeset
956 present, but is ignored as it is not necessary for Python.
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
957
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
958 The conversion types are:
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
959
25906
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
960 \begin{tableiii}{c|l|c}{character}{Conversion}{Meaning}{Notes}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
961 \lineiii{d}{Signed integer decimal.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
962 \lineiii{i}{Signed integer decimal.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
963 \lineiii{o}{Unsigned octal.}{(1)}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
964 \lineiii{u}{Unsigned decimal.}{}
34296
67f2190e1f6d SF Patch #1093896: miscellaneous doc typos
Raymond Hettinger <python@rcn.com>
parents: 34078
diff changeset
965 \lineiii{x}{Unsigned hexadecimal (lowercase).}{(2)}
67f2190e1f6d SF Patch #1093896: miscellaneous doc typos
Raymond Hettinger <python@rcn.com>
parents: 34078
diff changeset
966 \lineiii{X}{Unsigned hexadecimal (uppercase).}{(2)}
25906
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
967 \lineiii{e}{Floating point exponential format (lowercase).}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
968 \lineiii{E}{Floating point exponential format (uppercase).}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
969 \lineiii{f}{Floating point decimal format.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
970 \lineiii{F}{Floating point decimal format.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
971 \lineiii{g}{Same as \character{e} if exponent is greater than -4 or
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
972 less than precision, \character{f} otherwise.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
973 \lineiii{G}{Same as \character{E} if exponent is greater than -4 or
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
974 less than precision, \character{F} otherwise.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
975 \lineiii{c}{Single character (accepts integer or single character
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
976 string).}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
977 \lineiii{r}{String (converts any python object using
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
978 \function{repr()}).}{(3)}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
979 \lineiii{s}{String (converts any python object using
27225
5d42dba49fe5 SF patch 664183 and SF bug 664044: Note that both u'%s' % 'x' and
Raymond Hettinger <python@rcn.com>
parents: 27036
diff changeset
980 \function{str()}).}{(4)}
25906
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
981 \lineiii{\%}{No argument is converted, results in a \character{\%}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
982 character in the result.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
983 \end{tableiii}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
984
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
985 \noindent
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
986 Notes:
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
987 \begin{description}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
988 \item[(1)]
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
989 The alternate form causes a leading zero (\character{0}) to be
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
990 inserted between left-hand padding and the formatting of the
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
991 number if the leading character of the result is not already a
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
992 zero.
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
993 \item[(2)]
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
994 The alternate form causes a leading \code{'0x'} or \code{'0X'}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
995 (depending on whether the \character{x} or \character{X} format
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
996 was used) to be inserted between left-hand padding and the
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
997 formatting of the number if the leading character of the result is
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
998 not already a zero.
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
999 \item[(3)]
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
1000 The \code{\%r} conversion was added in Python 2.0.
27225
5d42dba49fe5 SF patch 664183 and SF bug 664044: Note that both u'%s' % 'x' and
Raymond Hettinger <python@rcn.com>
parents: 27036
diff changeset
1001 \item[(4)]
5d42dba49fe5 SF patch 664183 and SF bug 664044: Note that both u'%s' % 'x' and
Raymond Hettinger <python@rcn.com>
parents: 27036
diff changeset
1002 If the object or format provided is a \class{unicode} string,
5d42dba49fe5 SF patch 664183 and SF bug 664044: Note that both u'%s' % 'x' and
Raymond Hettinger <python@rcn.com>
parents: 27036
diff changeset
1003 the resulting string will also be \class{unicode}.
25906
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
1004 \end{description}
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1005
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1006 % XXX Examples?
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1007
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1008 Since Python strings have an explicit length, \code{\%s} conversions
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1009 do not assume that \code{'\e0'} is the end of the string.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1010
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1011 For safety reasons, floating point precisions are clipped to 50;
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1012 \code{\%f} conversions for numbers whose absolute value is over 1e25
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1013 are replaced by \code{\%g} conversions.\footnote{
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1014 These numbers are fairly arbitrary. They are intended to
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1015 avoid printing endless strings of meaningless digits without hampering
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1016 correct use and without having to know the exact precision of floating
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1017 point values on a particular machine.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1018 } All other errors raise exceptions.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
1019
21163
7b6879714b74 Make no assumption about how modules are built when referring to them; this
Fred Drake <fdrake@acm.org>
parents: 21159
diff changeset
1020 Additional string operations are defined in standard modules
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1021 \refmodule{string}\refstmodindex{string}\ and
22241
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1022 \refmodule{re}.\refstmodindex{re}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1023
13967
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach
Fred Drake <fdrake@acm.org>
parents: 13933
diff changeset
1024
14044
a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange()
Fred Drake <fdrake@acm.org>
parents: 13967
diff changeset
1025 \subsubsection{XRange Type \label{typesseq-xrange}}
13967
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach
Fred Drake <fdrake@acm.org>
parents: 13933
diff changeset
1026
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1027 The \class{xrange}\obindex{xrange} type is an immutable sequence which
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1028 is commonly used for looping. The advantage of the \class{xrange}
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1029 type is that an \class{xrange} object will always take the same amount
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1030 of memory, no matter the size of the range it represents. There are
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1031 no consistent performance advantages.
13967
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach
Fred Drake <fdrake@acm.org>
parents: 13933
diff changeset
1032
26592
0c646baeec58 Update comments about the performance of xrange().
Raymond Hettinger <python@rcn.com>
parents: 26514
diff changeset
1033 XRange objects have very little behavior: they only support indexing,
0c646baeec58 Update comments about the performance of xrange().
Raymond Hettinger <python@rcn.com>
parents: 26514
diff changeset
1034 iteration, and the \function{len()} function.
13967
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach
Fred Drake <fdrake@acm.org>
parents: 13933
diff changeset
1035
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach
Fred Drake <fdrake@acm.org>
parents: 13933
diff changeset
1036
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1037 \subsubsection{Mutable Sequence Types \label{typesseq-mutable}}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1038
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1039 List objects support additional operations that allow in-place
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1040 modification of the object.
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1041 Other mutable sequence types (when added to the language) should
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1042 also support these operations.
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1043 Strings and tuples are immutable sequence types: such objects cannot
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1044 be modified once created.
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1045 The following operations are defined on mutable sequence types (where
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1046 \var{x} is an arbitrary object):
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1047 \indexiii{mutable}{sequence}{types}
15005
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is
Fred Drake <fdrake@acm.org>
parents: 14710
diff changeset
1048 \obindex{list}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1049
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1050 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1051 \lineiii{\var{s}[\var{i}] = \var{x}}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1052 {item \var{i} of \var{s} is replaced by \var{x}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1053 \lineiii{\var{s}[\var{i}:\var{j}] = \var{t}}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1054 {slice of \var{s} from \var{i} to \var{j} is replaced by \var{t}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1055 \lineiii{del \var{s}[\var{i}:\var{j}]}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1056 {same as \code{\var{s}[\var{i}:\var{j}] = []}}{}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1057 \lineiii{\var{s}[\var{i}:\var{j}:\var{k}] = \var{t}}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1058 {the elements of \code{\var{s}[\var{i}:\var{j}:\var{k}]} are replaced by those of \var{t}}{(1)}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1059 \lineiii{del \var{s}[\var{i}:\var{j}:\var{k}]}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1060 {removes the elements of \code{\var{s}[\var{i}:\var{j}:\var{k}]} from the list}{}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1061 \lineiii{\var{s}.append(\var{x})}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1062 {same as \code{\var{s}[len(\var{s}):len(\var{s})] = [\var{x}]}}{(2)}
9318
8a26e55e18b8 Document the new list.extend() method. Interesting enough, the
Barry Warsaw <barry@python.org>
parents: 9083
diff changeset
1063 \lineiii{\var{s}.extend(\var{x})}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1064 {same as \code{\var{s}[len(\var{s}):len(\var{s})] = \var{x}}}{(3)}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1065 \lineiii{\var{s}.count(\var{x})}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1066 {return number of \var{i}'s for which \code{\var{s}[\var{i}] == \var{x}}}{}
29516
d761ff55b3be Updated documentation for the new slice arguments for list.index().
Walter Dörwald <walter@livinglogic.de>
parents: 29343
diff changeset
1067 \lineiii{\var{s}.index(\var{x}\optional{, \var{i}\optional{, \var{j}}})}
d761ff55b3be Updated documentation for the new slice arguments for list.index().
Walter Dörwald <walter@livinglogic.de>
parents: 29343
diff changeset
1068 {return smallest \var{k} such that \code{\var{s}[\var{k}] == \var{x}} and
d761ff55b3be Updated documentation for the new slice arguments for list.index().
Walter Dörwald <walter@livinglogic.de>
parents: 29343
diff changeset
1069 \code{\var{i} <= \var{k} < \var{j}}}{(4)}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1070 \lineiii{\var{s}.insert(\var{i}, \var{x})}
28606
436d812f2b94 - list.insert(i, x) now interprets negative i as it would be
Guido van Rossum <guido@python.org>
parents: 28337
diff changeset
1071 {same as \code{\var{s}[\var{i}:\var{i}] = [\var{x}]}}{(5)}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1072 \lineiii{\var{s}.pop(\optional{\var{i}})}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1073 {same as \code{\var{x} = \var{s}[\var{i}]; del \var{s}[\var{i}]; return \var{x}}}{(6)}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1074 \lineiii{\var{s}.remove(\var{x})}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1075 {same as \code{del \var{s}[\var{s}.index(\var{x})]}}{(4)}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1076 \lineiii{\var{s}.reverse()}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1077 {reverses the items of \var{s} in place}{(7)}
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1078 \lineiii{\var{s}.sort(\optional{\var{cmp}\optional{,
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1079 \var{key}\optional{, \var{reverse}}}})}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1080 {sort the items of \var{s} in place}{(7), (8), (9), (10)}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1081 \end{tableiii}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1082 \indexiv{operations on}{mutable}{sequence}{types}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1083 \indexiii{operations on}{sequence}{types}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1084 \indexiii{operations on}{list}{type}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1085 \indexii{subscript}{assignment}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1086 \indexii{slice}{assignment}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1087 \indexii{extended slice}{assignment}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1088 \stindex{del}
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1089 \withsubitem{(list method)}{
11183
1e0b1967be7f In note mentioning [].remove()'s exception, tell what exception is
Fred Drake <fdrake@acm.org>
parents: 11100
diff changeset
1090 \ttindex{append()}\ttindex{extend()}\ttindex{count()}\ttindex{index()}
1e0b1967be7f In note mentioning [].remove()'s exception, tell what exception is
Fred Drake <fdrake@acm.org>
parents: 11100
diff changeset
1091 \ttindex{insert()}\ttindex{pop()}\ttindex{remove()}\ttindex{reverse()}
9523
ed6cacddc6c6 Fix indexing of func_code attribute; this is on a function, not a code
Fred Drake <fdrake@acm.org>
parents: 9461
diff changeset
1092 \ttindex{sort()}}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1093 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1094 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1095 \begin{description}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1096 \item[(1)] \var{t} must have the same length as the slice it is
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1097 replacing.
23778
245224d1b8c9 This is my nearly two year old patch
Michael W. Hudson <mwh@python.net>
parents: 23515
diff changeset
1098
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1099 \item[(2)] The C implementation of Python has historically accepted
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1100 multiple parameters and implicitly joined them into a tuple; this
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1101 no longer works in Python 2.0. Use of this misfeature has been
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1102 deprecated since Python 1.4.
12223
e82e82b3b9ad Merged changes from the 1.5.2p2 release.
Fred Drake <fdrake@acm.org>
parents: 11463
diff changeset
1103
34573
19327db75d1c SF bug #1119700: list extend() accepts args besides lists
Raymond Hettinger <python@rcn.com>
parents: 34508
diff changeset
1104 \item[(3)] \var{x} can be any iterable object.
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1105
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1106 \item[(4)] Raises \exception{ValueError} when \var{x} is not found in
29516
d761ff55b3be Updated documentation for the new slice arguments for list.index().
Walter Dörwald <walter@livinglogic.de>
parents: 29343
diff changeset
1107 \var{s}. When a negative index is passed as the second or third parameter
d761ff55b3be Updated documentation for the new slice arguments for list.index().
Walter Dörwald <walter@livinglogic.de>
parents: 29343
diff changeset
1108 to the \method{index()} method, the list length is added, as for slice
d761ff55b3be Updated documentation for the new slice arguments for list.index().
Walter Dörwald <walter@livinglogic.de>
parents: 29343
diff changeset
1109 indices. If it is still negative, it is truncated to zero, as for
d761ff55b3be Updated documentation for the new slice arguments for list.index().
Walter Dörwald <walter@livinglogic.de>
parents: 29343
diff changeset
1110 slice indices. \versionchanged[Previously, \method{index()} didn't
d761ff55b3be Updated documentation for the new slice arguments for list.index().
Walter Dörwald <walter@livinglogic.de>
parents: 29343
diff changeset
1111 have arguments for specifying start and stop positions]{2.3}
11183
1e0b1967be7f In note mentioning [].remove()'s exception, tell what exception is
Fred Drake <fdrake@acm.org>
parents: 11100
diff changeset
1112
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1113 \item[(5)] When a negative index is passed as the first parameter to
28606
436d812f2b94 - list.insert(i, x) now interprets negative i as it would be
Guido van Rossum <guido@python.org>
parents: 28337
diff changeset
1114 the \method{insert()} method, the list length is added, as for slice
436d812f2b94 - list.insert(i, x) now interprets negative i as it would be
Guido van Rossum <guido@python.org>
parents: 28337
diff changeset
1115 indices. If it is still negative, it is truncated to zero, as for
436d812f2b94 - list.insert(i, x) now interprets negative i as it would be
Guido van Rossum <guido@python.org>
parents: 28337
diff changeset
1116 slice indices. \versionchanged[Previously, all negative indices
436d812f2b94 - list.insert(i, x) now interprets negative i as it would be
Guido van Rossum <guido@python.org>
parents: 28337
diff changeset
1117 were truncated to zero]{2.3}
20701
5f6850d1f9e8 Explain what [].insert() does when the target index is negative.
Fred Drake <fdrake@acm.org>
parents: 20580
diff changeset
1118
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1119 \item[(6)] The \method{pop()} method is only supported by the list and
13777
b3903e05017f Stop lying about [].pop() being experimental! There is no backing it out
Fred Drake <fdrake@acm.org>
parents: 13772
diff changeset
1120 array types. The optional argument \var{i} defaults to \code{-1},
b3903e05017f Stop lying about [].pop() being experimental! There is no backing it out
Fred Drake <fdrake@acm.org>
parents: 13772
diff changeset
1121 so that by default the last item is removed and returned.
12223
e82e82b3b9ad Merged changes from the 1.5.2p2 release.
Fred Drake <fdrake@acm.org>
parents: 11463
diff changeset
1122
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1123 \item[(7)] The \method{sort()} and \method{reverse()} methods modify the
12223
e82e82b3b9ad Merged changes from the 1.5.2p2 release.
Fred Drake <fdrake@acm.org>
parents: 11463
diff changeset
1124 list in place for economy of space when sorting or reversing a large
18829
1bc1fdf1482b trivial rewording in footnote 5.
Skip Montanaro <skip@pobox.com>
parents: 18416
diff changeset
1125 list. To remind you that they operate by side effect, they don't return
1bc1fdf1482b trivial rewording in footnote 5.
Skip Montanaro <skip@pobox.com>
parents: 18416
diff changeset
1126 the sorted or reversed list.
12223
e82e82b3b9ad Merged changes from the 1.5.2p2 release.
Fred Drake <fdrake@acm.org>
parents: 11463
diff changeset
1127
31210
c06b570adf12 Guido grants a Christmas wish:
Raymond Hettinger <python@rcn.com>
parents: 31206
diff changeset
1128 \item[(8)] The \method{sort()} method takes optional arguments for
33448
5570fae1f01c Typo fix: 'comparisions' is not a word
Andrew M. Kuchling <amk@amk.ca>
parents: 33412
diff changeset
1129 controlling the comparisons.
30697
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1130
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1131 \var{cmp} specifies a custom comparison function of two arguments
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1132 (list items) which should return a negative, zero or positive number
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1133 depending on whether the first argument is considered smaller than,
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1134 equal to, or larger than the second argument:
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1135 \samp{\var{cmp}=\keyword{lambda} \var{x},\var{y}:
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1136 \function{cmp}(x.lower(), y.lower())}
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1137
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1138 \var{key} specifies a function of one argument that is used to
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1139 extract a comparison key from each list element:
34078
4b601bd346a4 Backport minor documentation fixups.
Raymond Hettinger <python@rcn.com>
parents: 34029
diff changeset
1140 \samp{\var{key}=\function{str.lower}}
30697
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1141
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1142 \var{reverse} is a boolean value. If set to \code{True}, then the
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1143 list elements are sorted as if each comparison were reversed.
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1144
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1145 In general, the \var{key} and \var{reverse} conversion processes are
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1146 much faster than specifying an equivalent \var{cmp} function. This is
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1147 because \var{cmp} is called multiple times for each list element while
30737
38b0b7d41936 markup fixes; this would not format
Fred Drake <fdrake@acm.org>
parents: 30707
diff changeset
1148 \var{key} and \var{reverse} touch each element only once.
30697
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1149
28337
90f17c374f59 - added example of using a comparison function with list.sort(), and
Fred Drake <fdrake@acm.org>
parents: 28211
diff changeset
1150 \versionchanged[Support for \code{None} as an equivalent to omitting
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1151 \var{cmp} was added]{2.3}
28337
90f17c374f59 - added example of using a comparison function with list.sort(), and
Fred Drake <fdrake@acm.org>
parents: 28211
diff changeset
1152
30737
38b0b7d41936 markup fixes; this would not format
Fred Drake <fdrake@acm.org>
parents: 30707
diff changeset
1153 \versionchanged[Support for \var{key} and \var{reverse} was added]{2.4}
28337
90f17c374f59 - added example of using a comparison function with list.sort(), and
Fred Drake <fdrake@acm.org>
parents: 28211
diff changeset
1154
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1155 \item[(9)] Starting with Python 2.3, the \method{sort()} method is
31210
c06b570adf12 Guido grants a Christmas wish:
Raymond Hettinger <python@rcn.com>
parents: 31206
diff changeset
1156 guaranteed to be stable. A sort is stable if it guarantees not to
30697
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1157 change the relative order of elements that compare equal --- this is
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1158 helpful for sorting in multiple passes (for example, sort by
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1159 department, then by salary grade).
26161
dd10d97d329a SF patch 637176: list.sort crasher
Tim Peters <tim.peters@gmail.com>
parents: 25906
diff changeset
1160
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1161 \item[(10)] While a list is being sorted, the effect of attempting to
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1162 mutate, or even inspect, the list is undefined. The C
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1163 implementation of Python 2.3 and newer makes the list appear empty
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1164 for the duration, and raises \exception{ValueError} if it can detect
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1165 that the list has been mutated during a sort.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1166 \end{description}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1167
35074
f89cbe69db63 SF bug #1215887: String and list methods documentation deeply hidden
Raymond Hettinger <python@rcn.com>
parents: 34975
diff changeset
1168 \subsection{Set Types ---
f89cbe69db63 SF bug #1215887: String and list methods documentation deeply hidden
Raymond Hettinger <python@rcn.com>
parents: 34975
diff changeset
1169 \class{set}, \class{frozenset}
f89cbe69db63 SF bug #1215887: String and list methods documentation deeply hidden
Raymond Hettinger <python@rcn.com>
parents: 34975
diff changeset
1170 \label{types-set}}
31008
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diff changeset
1171 \obindex{set}
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1172
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parents: 30813
diff changeset
1173 A \dfn{set} object is an unordered collection of immutable values.
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parents: 30813
diff changeset
1174 Common uses include membership testing, removing duplicates from a sequence,
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parents: 30813
diff changeset
1175 and computing mathematical operations such as intersection, union, difference,
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parents: 30813
diff changeset
1176 and symmetric difference.
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parents: 30813
diff changeset
1177 \versionadded{2.4}
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parents: 30813
diff changeset
1178
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parents: 30813
diff changeset
1179 Like other collections, sets support \code{\var{x} in \var{set}},
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parents: 30813
diff changeset
1180 \code{len(\var{set})}, and \code{for \var{x} in \var{set}}. Being an
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parents: 30813
diff changeset
1181 unordered collection, sets do not record element position or order of
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parents: 30813
diff changeset
1182 insertion. Accordingly, sets do not support indexing, slicing, or
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parents: 30813
diff changeset
1183 other sequence-like behavior.
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parents: 30813
diff changeset
1184
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parents: 30813
diff changeset
1185 There are currently two builtin set types, \class{set} and \class{frozenset}.
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parents: 30813
diff changeset
1186 The \class{set} type is mutable --- the contents can be changed using methods
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Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1187 like \method{add()} and \method{remove()}. Since it is mutable, it has no
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Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1188 hash value and cannot be used as either a dictionary key or as an element of
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Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1189 another set. The \class{frozenset} type is immutable and hashable --- its
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1190 contents cannot be altered after is created; however, it can be used as
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1191 a dictionary key or as an element of another set.
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1192
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parents: 30813
diff changeset
1193 Instances of \class{set} and \class{frozenset} provide the following operations:
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parents: 30813
diff changeset
1194
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parents: 30813
diff changeset
1195 \begin{tableiii}{c|c|l}{code}{Operation}{Equivalent}{Result}
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parents: 30813
diff changeset
1196 \lineiii{len(\var{s})}{}{cardinality of set \var{s}}
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parents: 30813
diff changeset
1197
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parents: 30813
diff changeset
1198 \hline
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parents: 30813
diff changeset
1199 \lineiii{\var{x} in \var{s}}{}
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parents: 30813
diff changeset
1200 {test \var{x} for membership in \var{s}}
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parents: 30813
diff changeset
1201 \lineiii{\var{x} not in \var{s}}{}
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parents: 30813
diff changeset
1202 {test \var{x} for non-membership in \var{s}}
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parents: 30813
diff changeset
1203 \lineiii{\var{s}.issubset(\var{t})}{\code{\var{s} <= \var{t}}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1204 {test whether every element in \var{s} is in \var{t}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1205 \lineiii{\var{s}.issuperset(\var{t})}{\code{\var{s} >= \var{t}}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1206 {test whether every element in \var{t} is in \var{s}}
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parents: 30813
diff changeset
1207
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parents: 30813
diff changeset
1208 \hline
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parents: 30813
diff changeset
1209 \lineiii{\var{s}.union(\var{t})}{\var{s} | \var{t}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1210 {new set with elements from both \var{s} and \var{t}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1211 \lineiii{\var{s}.intersection(\var{t})}{\var{s} \&\ \var{t}}
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parents: 30813
diff changeset
1212 {new set with elements common to \var{s} and \var{t}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1213 \lineiii{\var{s}.difference(\var{t})}{\var{s} - \var{t}}
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parents: 30813
diff changeset
1214 {new set with elements in \var{s} but not in \var{t}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1215 \lineiii{\var{s}.symmetric_difference(\var{t})}{\var{s} \^\ \var{t}}
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parents: 30813
diff changeset
1216 {new set with elements in either \var{s} or \var{t} but not both}
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parents: 30813
diff changeset
1217 \lineiii{\var{s}.copy()}{}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1218 {new set with a shallow copy of \var{s}}
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parents: 30813
diff changeset
1219 \end{tableiii}
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parents: 30813
diff changeset
1220
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parents: 30813
diff changeset
1221 Note, the non-operator versions of \method{union()}, \method{intersection()},
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parents: 30813
diff changeset
1222 \method{difference()}, and \method{symmetric_difference()},
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parents: 30813
diff changeset
1223 \method{issubset()}, and \method{issuperset()} methods will accept any
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Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1224 iterable as an argument. In contrast, their operator based counterparts
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1225 require their arguments to be sets. This precludes error-prone constructions
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1226 like \code{set('abc') \&\ 'cbs'} in favor of the more readable
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1227 \code{set('abc').intersection('cbs')}.
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parents: 30813
diff changeset
1228
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1229 Both \class{set} and \class{frozenset} support set to set comparisons.
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1230 Two sets are equal if and only if every element of each set is contained in
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parents: 30813
diff changeset
1231 the other (each is a subset of the other).
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parents: 30813
diff changeset
1232 A set is less than another set if and only if the first set is a proper
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1233 subset of the second set (is a subset, but is not equal).
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parents: 30813
diff changeset
1234 A set is greater than another set if and only if the first set is a proper
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parents: 30813
diff changeset
1235 superset of the second set (is a superset, but is not equal).
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parents: 30813
diff changeset
1236
34296
67f2190e1f6d SF Patch #1093896: miscellaneous doc typos
Raymond Hettinger <python@rcn.com>
parents: 34078
diff changeset
1237 Instances of \class{set} are compared to instances of \class{frozenset} based
32795
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
Raymond Hettinger <python@rcn.com>
parents: 32459
diff changeset
1238 on their members. For example, \samp{set('abc') == frozenset('abc')} returns
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
Raymond Hettinger <python@rcn.com>
parents: 32459
diff changeset
1239 \code{True}.
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
Raymond Hettinger <python@rcn.com>
parents: 32459
diff changeset
1240
31008
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diff changeset
1241 The subset and equality comparisons do not generalize to a complete
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parents: 30813
diff changeset
1242 ordering function. For example, any two disjoint sets are not equal and
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parents: 30813
diff changeset
1243 are not subsets of each other, so \emph{all} of the following return
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parents: 30813
diff changeset
1244 \code{False}: \code{\var{a}<\var{b}}, \code{\var{a}==\var{b}}, or
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diff changeset
1245 \code{\var{a}>\var{b}}.
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parents: 30813
diff changeset
1246 Accordingly, sets do not implement the \method{__cmp__} method.
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parents: 30813
diff changeset
1247
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parents: 30813
diff changeset
1248 Since sets only define partial ordering (subset relationships), the output
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1249 of the \method{list.sort()} method is undefined for lists of sets.
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parents: 30813
diff changeset
1250
34898
fbcb1da480dd SF bug #1179957: Missing def'n of equality for set element
Raymond Hettinger <python@rcn.com>
parents: 34573
diff changeset
1251 Set elements are like dictionary keys; they need to define both
fbcb1da480dd SF bug #1179957: Missing def'n of equality for set element
Raymond Hettinger <python@rcn.com>
parents: 34573
diff changeset
1252 \method{__hash__} and \method{__eq__} methods.
fbcb1da480dd SF bug #1179957: Missing def'n of equality for set element
Raymond Hettinger <python@rcn.com>
parents: 34573
diff changeset
1253
32795
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
Raymond Hettinger <python@rcn.com>
parents: 32459
diff changeset
1254 Binary operations that mix \class{set} instances with \class{frozenset}
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
Raymond Hettinger <python@rcn.com>
parents: 32459
diff changeset
1255 return the type of the first operand. For example:
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
Raymond Hettinger <python@rcn.com>
parents: 32459
diff changeset
1256 \samp{frozenset('ab') | set('bc')} returns an instance of \class{frozenset}.
31008
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parents: 30813
diff changeset
1257
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parents: 30813
diff changeset
1258 The following table lists operations available for \class{set}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1259 that do not apply to immutable instances of \class{frozenset}:
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parents: 30813
diff changeset
1260
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parents: 30813
diff changeset
1261 \begin{tableiii}{c|c|l}{code}{Operation}{Equivalent}{Result}
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parents: 30813
diff changeset
1262 \lineiii{\var{s}.update(\var{t})}
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parents: 30813
diff changeset
1263 {\var{s} |= \var{t}}
36136
c886cb16a156 Bug #1389673: document correct return value of set methods (backport)
Georg Brandl <georg@python.org>
parents: 36038
diff changeset
1264 {update set \var{s}, adding elements from \var{t}}
31008
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diff changeset
1265 \lineiii{\var{s}.intersection_update(\var{t})}
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parents: 30813
diff changeset
1266 {\var{s} \&= \var{t}}
36136
c886cb16a156 Bug #1389673: document correct return value of set methods (backport)
Georg Brandl <georg@python.org>
parents: 36038
diff changeset
1267 {update set \var{s}, keeping only elements found in both \var{s} and \var{t}}
31008
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diff changeset
1268 \lineiii{\var{s}.difference_update(\var{t})}
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parents: 30813
diff changeset
1269 {\var{s} -= \var{t}}
36136
c886cb16a156 Bug #1389673: document correct return value of set methods (backport)
Georg Brandl <georg@python.org>
parents: 36038
diff changeset
1270 {update set \var{s}, removing elements found in \var{t}}
31008
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diff changeset
1271 \lineiii{\var{s}.symmetric_difference_update(\var{t})}
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parents: 30813
diff changeset
1272 {\var{s} \textasciicircum= \var{t}}
36136
c886cb16a156 Bug #1389673: document correct return value of set methods (backport)
Georg Brandl <georg@python.org>
parents: 36038
diff changeset
1273 {update set \var{s}, keeping only elements found in either \var{s} or \var{t}
c886cb16a156 Bug #1389673: document correct return value of set methods (backport)
Georg Brandl <georg@python.org>
parents: 36038
diff changeset
1274 but not in both}
31008
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diff changeset
1275
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diff changeset
1276 \hline
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diff changeset
1277 \lineiii{\var{s}.add(\var{x})}{}
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parents: 30813
diff changeset
1278 {add element \var{x} to set \var{s}}
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parents: 30813
diff changeset
1279 \lineiii{\var{s}.remove(\var{x})}{}
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parents: 30813
diff changeset
1280 {remove \var{x} from set \var{s}; raises KeyError if not present}
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parents: 30813
diff changeset
1281 \lineiii{\var{s}.discard(\var{x})}{}
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diff changeset
1282 {removes \var{x} from set \var{s} if present}
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diff changeset
1283 \lineiii{\var{s}.pop()}{}
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parents: 30813
diff changeset
1284 {remove and return an arbitrary element from \var{s}; raises
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diff changeset
1285 \exception{KeyError} if empty}
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parents: 30813
diff changeset
1286 \lineiii{\var{s}.clear()}{}
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parents: 30813
diff changeset
1287 {remove all elements from set \var{s}}
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diff changeset
1288 \end{tableiii}
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diff changeset
1289
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diff changeset
1290 Note, the non-operator versions of the \method{update()},
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diff changeset
1291 \method{intersection_update()}, \method{difference_update()}, and
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diff changeset
1292 \method{symmetric_difference_update()} methods will accept any iterable
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diff changeset
1293 as an argument.
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diff changeset
1294
35187
5d977d7cc335 Cross reference the set built-ins with the sets module.
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diff changeset
1295 The design of the set types was based on lessons learned from the
5d977d7cc335 Cross reference the set built-ins with the sets module.
Raymond Hettinger <python@rcn.com>
parents: 35074
diff changeset
1296 \module{sets} module.
5d977d7cc335 Cross reference the set built-ins with the sets module.
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parents: 35074
diff changeset
1297
5d977d7cc335 Cross reference the set built-ins with the sets module.
Raymond Hettinger <python@rcn.com>
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diff changeset
1298 \begin{seealso}
35687
2985e42eb2d2 fix link to subsection (SF bug #1311674)
Fred Drake <fdrake@acm.org>
parents: 35202
diff changeset
1299 \seelink{comparison-to-builtin-set.html}
2985e42eb2d2 fix link to subsection (SF bug #1311674)
Fred Drake <fdrake@acm.org>
parents: 35202
diff changeset
1300 {Comparison to the built-in set types}
2985e42eb2d2 fix link to subsection (SF bug #1311674)
Fred Drake <fdrake@acm.org>
parents: 35202
diff changeset
1301 {Differences between the \module{sets} module and the
2985e42eb2d2 fix link to subsection (SF bug #1311674)
Fred Drake <fdrake@acm.org>
parents: 35202
diff changeset
1302 built-in set types.}
35187
5d977d7cc335 Cross reference the set built-ins with the sets module.
Raymond Hettinger <python@rcn.com>
parents: 35074
diff changeset
1303 \end{seealso}
5d977d7cc335 Cross reference the set built-ins with the sets module.
Raymond Hettinger <python@rcn.com>
parents: 35074
diff changeset
1304
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1305
35074
f89cbe69db63 SF bug #1215887: String and list methods documentation deeply hidden
Raymond Hettinger <python@rcn.com>
parents: 34975
diff changeset
1306 \subsection{Mapping Types --- class{dict} \label{typesmapping}}
15005
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is
Fred Drake <fdrake@acm.org>
parents: 14710
diff changeset
1307 \obindex{mapping}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is
Fred Drake <fdrake@acm.org>
parents: 14710
diff changeset
1308 \obindex{dictionary}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1309
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1310 A \dfn{mapping} object maps immutable values to
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1311 arbitrary objects. Mappings are mutable objects. There is currently
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1312 only one standard mapping type, the \dfn{dictionary}. A dictionary's keys are
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1313 almost arbitrary values. Only values containing lists, dictionaries
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1314 or other mutable types (that are compared by value rather than by
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1315 object identity) may not be used as keys.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1316 Numeric types used for keys obey the normal rules for numeric
30413
53f1c32ee69d SF bug #804280: fromkeys is not listed in index
Raymond Hettinger <python@rcn.com>
parents: 30375
diff changeset
1317 comparison: if two numbers compare equal (such as \code{1} and
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1318 \code{1.0}) then they can be used interchangeably to index the same
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1319 dictionary entry.
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1320
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1321 Dictionaries are created by placing a comma-separated list of
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1322 \code{\var{key}: \var{value}} pairs within braces, for example:
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1323 \code{\{'jack': 4098, 'sjoerd': 4127\}} or
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1324 \code{\{4098: 'jack', 4127: 'sjoerd'\}}.
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1325
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1326 The following operations are defined on mappings (where \var{a} and
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1327 \var{b} are mappings, \var{k} is a key, and \var{v} and \var{x} are
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1328 arbitrary objects):
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1329 \indexiii{operations on}{mapping}{types}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1330 \indexiii{operations on}{dictionary}{type}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1331 \stindex{del}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1332 \bifuncindex{len}
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1333 \withsubitem{(dictionary method)}{
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1334 \ttindex{clear()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1335 \ttindex{copy()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1336 \ttindex{has_key()}
30413
53f1c32ee69d SF bug #804280: fromkeys is not listed in index
Raymond Hettinger <python@rcn.com>
parents: 30375
diff changeset
1337 \ttindex{fromkeys()}
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1338 \ttindex{items()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1339 \ttindex{keys()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1340 \ttindex{update()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1341 \ttindex{values()}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1342 \ttindex{get()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1343 \ttindex{setdefault()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1344 \ttindex{pop()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1345 \ttindex{popitem()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1346 \ttindex{iteritems()}
29067
04065c4a1c6b Missing parenthesis found by texcheck.py
Raymond Hettinger <python@rcn.com>
parents: 29065
diff changeset
1347 \ttindex{iterkeys()}
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1348 \ttindex{itervalues()}}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1349
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1350 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1351 \lineiii{len(\var{a})}{the number of items in \var{a}}{}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1352 \lineiii{\var{a}[\var{k}]}{the item of \var{a} with key \var{k}}{(1)}
13764
fdbc8730d356 Two minor nits from Gerry Weiner (no working email address) about
Fred Drake <fdrake@acm.org>
parents: 13222
diff changeset
1353 \lineiii{\var{a}[\var{k}] = \var{v}}
fdbc8730d356 Two minor nits from Gerry Weiner (no working email address) about
Fred Drake <fdrake@acm.org>
parents: 13222
diff changeset
1354 {set \code{\var{a}[\var{k}]} to \var{v}}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1355 {}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1356 \lineiii{del \var{a}[\var{k}]}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1357 {remove \code{\var{a}[\var{k}]} from \var{a}}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1358 {(1)}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1359 \lineiii{\var{a}.clear()}{remove all items from \code{a}}{}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1360 \lineiii{\var{a}.copy()}{a (shallow) copy of \code{a}}{}
17616
7acba78e1e09 At the suggestion of Peter Funk, document 'key in dict' and 'key not
Guido van Rossum <guido@python.org>
parents: 17612
diff changeset
1361 \lineiii{\var{a}.has_key(\var{k})}
30095
e3c9b48de60a SF bug #775836: change 0,1 to False,True in dict.has_key doc
Raymond Hettinger <python@rcn.com>
parents: 29893
diff changeset
1362 {\code{True} if \var{a} has a key \var{k}, else \code{False}}
17594
bf94af396b1e Implement, test and document "key in dict" and "key not in dict".
Guido van Rossum <guido@python.org>
parents: 16778
diff changeset
1363 {}
17616
7acba78e1e09 At the suggestion of Peter Funk, document 'key in dict' and 'key not
Guido van Rossum <guido@python.org>
parents: 17612
diff changeset
1364 \lineiii{\var{k} \code{in} \var{a}}
7acba78e1e09 At the suggestion of Peter Funk, document 'key in dict' and 'key not
Guido van Rossum <guido@python.org>
parents: 17612
diff changeset
1365 {Equivalent to \var{a}.has_key(\var{k})}
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1366 {(2)}
17594
bf94af396b1e Implement, test and document "key in dict" and "key not in dict".
Guido van Rossum <guido@python.org>
parents: 16778
diff changeset
1367 \lineiii{\var{k} not in \var{a}}
17616
7acba78e1e09 At the suggestion of Peter Funk, document 'key in dict' and 'key not
Guido van Rossum <guido@python.org>
parents: 17612
diff changeset
1368 {Equivalent to \code{not} \var{a}.has_key(\var{k})}
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1369 {(2)}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1370 \lineiii{\var{a}.items()}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1371 {a copy of \var{a}'s list of (\var{key}, \var{value}) pairs}
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1372 {(3)}
18085
7e459fb3c332 Fixed reference to table notes for {}.keys() and {}.items() -- these
Fred Drake <fdrake@acm.org>
parents: 17966
diff changeset
1373 \lineiii{\var{a}.keys()}{a copy of \var{a}'s list of keys}{(3)}
31616
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1374 \lineiii{\var{a}.update(\optional{\var{b}})}
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1375 {updates (and overwrites) key/value pairs from \var{b}}
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1376 {(9)}
26437
57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class
Raymond Hettinger <python@rcn.com>
parents: 26260
diff changeset
1377 \lineiii{\var{a}.fromkeys(\var{seq}\optional{, \var{value}})}
57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class
Raymond Hettinger <python@rcn.com>
parents: 26260
diff changeset
1378 {Creates a new dictionary with keys from \var{seq} and values set to \var{value}}
57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class
Raymond Hettinger <python@rcn.com>
parents: 26260
diff changeset
1379 {(7)}
18085
7e459fb3c332 Fixed reference to table notes for {}.keys() and {}.items() -- these
Fred Drake <fdrake@acm.org>
parents: 17966
diff changeset
1380 \lineiii{\var{a}.values()}{a copy of \var{a}'s list of values}{(3)}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1381 \lineiii{\var{a}.get(\var{k}\optional{, \var{x}})}
17603
d638e419c304 Fix a number of minor markup errors.
Fred Drake <fdrake@acm.org>
parents: 17594
diff changeset
1382 {\code{\var{a}[\var{k}]} if \code{\var{k} in \var{a}},
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1383 else \var{x}}
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1384 {(4)}
13894
77b9e041b595 Barry's patch to document the new setdefault() method. Slightly
Guido van Rossum <guido@python.org>
parents: 13780
diff changeset
1385 \lineiii{\var{a}.setdefault(\var{k}\optional{, \var{x}})}
17603
d638e419c304 Fix a number of minor markup errors.
Fred Drake <fdrake@acm.org>
parents: 17594
diff changeset
1386 {\code{\var{a}[\var{k}]} if \code{\var{k} in \var{a}},
13894
77b9e041b595 Barry's patch to document the new setdefault() method. Slightly
Guido van Rossum <guido@python.org>
parents: 13780
diff changeset
1387 else \var{x} (also setting it)}
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1388 {(5)}
28211
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop
Raymond Hettinger <python@rcn.com>
parents: 28171
diff changeset
1389 \lineiii{\var{a}.pop(\var{k}\optional{, \var{x}})}
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop
Raymond Hettinger <python@rcn.com>
parents: 28171
diff changeset
1390 {\code{\var{a}[\var{k}]} if \code{\var{k} in \var{a}},
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop
Raymond Hettinger <python@rcn.com>
parents: 28171
diff changeset
1391 else \var{x} (and remove k)}
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop
Raymond Hettinger <python@rcn.com>
parents: 28171
diff changeset
1392 {(8)}
15522
aaa54752e4ba "Documentation" for {}.popitem().
Guido van Rossum <guido@python.org>
parents: 15463
diff changeset
1393 \lineiii{\var{a}.popitem()}
aaa54752e4ba "Documentation" for {}.popitem().
Guido van Rossum <guido@python.org>
parents: 15463
diff changeset
1394 {remove and return an arbitrary (\var{key}, \var{value}) pair}
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1395 {(6)}
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1396 \lineiii{\var{a}.iteritems()}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1397 {return an iterator over (\var{key}, \var{value}) pairs}
24902
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1398 {(2), (3)}
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1399 \lineiii{\var{a}.iterkeys()}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1400 {return an iterator over the mapping's keys}
24902
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1401 {(2), (3)}
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1402 \lineiii{\var{a}.itervalues()}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1403 {return an iterator over the mapping's values}
24902
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1404 {(2), (3)}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1405 \end{tableiii}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1406
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1407 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1408 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1409 \begin{description}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1410 \item[(1)] Raises a \exception{KeyError} exception if \var{k} is not
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1411 in the map.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1412
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1413 \item[(2)] \versionadded{2.2}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1414
34029
81a1f754d32c Clarify the ordering of dictionary keys.
Raymond Hettinger <python@rcn.com>
parents: 33970
diff changeset
1415 \item[(3)] Keys and values are listed in an arbitrary order which is
81a1f754d32c Clarify the ordering of dictionary keys.
Raymond Hettinger <python@rcn.com>
parents: 33970
diff changeset
1416 non-random, varies across Python implementations, and depends on the
81a1f754d32c Clarify the ordering of dictionary keys.
Raymond Hettinger <python@rcn.com>
parents: 33970
diff changeset
1417 dictionary's history of insertions and deletions.
81a1f754d32c Clarify the ordering of dictionary keys.
Raymond Hettinger <python@rcn.com>
parents: 33970
diff changeset
1418 If \method{items()}, \method{keys()}, \method{values()},
24902
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1419 \method{iteritems()}, \method{iterkeys()}, and \method{itervalues()}
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1420 are called with no intervening modifications to the dictionary, the
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1421 lists will directly correspond. This allows the creation of
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1422 \code{(\var{value}, \var{key})} pairs using \function{zip()}:
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1423 \samp{pairs = zip(\var{a}.values(), \var{a}.keys())}. The same
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1424 relationship holds for the \method{iterkeys()} and
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1425 \method{itervalues()} methods: \samp{pairs = zip(\var{a}.itervalues(),
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1426 \var{a}.iterkeys())} provides the same value for \code{pairs}.
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1427 Another way to create the same list is \samp{pairs = [(v, k) for (k,
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1428 v) in \var{a}.iteritems()]}.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1429
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1430 \item[(4)] Never raises an exception if \var{k} is not in the map,
12223
e82e82b3b9ad Merged changes from the 1.5.2p2 release.
Fred Drake <fdrake@acm.org>
parents: 11463
diff changeset
1431 instead it returns \var{x}. \var{x} is optional; when \var{x} is not
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1432 provided and \var{k} is not in the map, \code{None} is returned.
13894
77b9e041b595 Barry's patch to document the new setdefault() method. Slightly
Guido van Rossum <guido@python.org>
parents: 13780
diff changeset
1433
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1434 \item[(5)] \function{setdefault()} is like \function{get()}, except
13894
77b9e041b595 Barry's patch to document the new setdefault() method. Slightly
Guido van Rossum <guido@python.org>
parents: 13780
diff changeset
1435 that if \var{k} is missing, \var{x} is both returned and inserted into
33003
b5dcfe7a4159 Point out that the setdefault defaults the value to None. Inspired by
Michael W. Hudson <mwh@python.net>
parents: 32975
diff changeset
1436 the dictionary as the value of \var{k}. \var{x} defaults to \var{None}.
15522
aaa54752e4ba "Documentation" for {}.popitem().
Guido van Rossum <guido@python.org>
parents: 15463
diff changeset
1437
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1438 \item[(6)] \function{popitem()} is useful to destructively iterate
34969
672e5f65172c SF bug #1209671: dict.popitem documentation should mention empty dict case
Raymond Hettinger <python@rcn.com>
parents: 34917
diff changeset
1439 over a dictionary, as often used in set algorithms. If the dictionary
672e5f65172c SF bug #1209671: dict.popitem documentation should mention empty dict case
Raymond Hettinger <python@rcn.com>
parents: 34917
diff changeset
1440 is empty, calling \function{popitem()} raises a \exception{KeyError}.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1441
26437
57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class
Raymond Hettinger <python@rcn.com>
parents: 26260
diff changeset
1442 \item[(7)] \function{fromkeys()} is a class method that returns a
57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class
Raymond Hettinger <python@rcn.com>
parents: 26260
diff changeset
1443 new dictionary. \var{value} defaults to \code{None}. \versionadded{2.3}
28211
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop
Raymond Hettinger <python@rcn.com>
parents: 28171
diff changeset
1444
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop
Raymond Hettinger <python@rcn.com>
parents: 28171
diff changeset
1445 \item[(8)] \function{pop()} raises a \exception{KeyError} when no default
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop
Raymond Hettinger <python@rcn.com>
parents: 28171
diff changeset
1446 value is given and the key is not found. \versionadded{2.3}
26437
57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class
Raymond Hettinger <python@rcn.com>
parents: 26260
diff changeset
1447
31616
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1448 \item[(9)] \function{update()} accepts either another mapping object
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1449 or an iterable of key/value pairs (as a tuple or other iterable of
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1450 length two). If keyword arguments are specified, the mapping is
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1451 then is updated with those key/value pairs:
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1452 \samp{d.update(red=1, blue=2)}.
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1453 \versionchanged[Allowed the argument to be an iterable of key/value
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1454 pairs and allowed keyword arguments]{2.4}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1455
31631
228d264c5fbb SF Patch #912462: Relocate \end tag to the right place.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31616
diff changeset
1456 \end{description}
228d264c5fbb SF Patch #912462: Relocate \end tag to the right place.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31616
diff changeset
1457
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1458 \subsection{File Objects
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1459 \label{bltin-file-objects}}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1460
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1461 File objects\obindex{file} are implemented using C's \code{stdio}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1462 package and can be created with the built-in constructor
22241
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1463 \function{file()}\bifuncindex{file} described in section
20764
37b8d92e12f5 Mention the new file() builtin in the section on file objects.
Tim Peters <tim.peters@gmail.com>
parents: 20701
diff changeset
1464 \ref{built-in-funcs}, ``Built-in Functions.''\footnote{\function{file()}
37b8d92e12f5 Mention the new file() builtin in the section on file objects.
Tim Peters <tim.peters@gmail.com>
parents: 20701
diff changeset
1465 is new in Python 2.2. The older built-in \function{open()} is an
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1466 alias for \function{file()}.} File objects are also returned
18416
33b4357aebb8 Fix up a few style nits -- avoid "e.g." and "i.e." -- these make
Fred Drake <fdrake@acm.org>
parents: 18395
diff changeset
1467 by some other built-in functions and methods, such as
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
1468 \function{os.popen()} and \function{os.fdopen()} and the
9461
9ffd604807c2 Don't describe something as "below"; that won't make sense for the
Fred Drake <fdrake@acm.org>
parents: 9318
diff changeset
1469 \method{makefile()} method of socket objects.
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
1470 \refstmodindex{os}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1471 \refbimodindex{socket}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1472
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1473 When a file operation fails for an I/O-related reason, the exception
9558
fa867d8ee7eb Remove some remaining {\rm ...} constructs.
Fred Drake <fdrake@acm.org>
parents: 9523
diff changeset
1474 \exception{IOError} is raised. This includes situations where the
fa867d8ee7eb Remove some remaining {\rm ...} constructs.
Fred Drake <fdrake@acm.org>
parents: 9523
diff changeset
1475 operation is not defined for some reason, like \method{seek()} on a tty
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1476 device or writing a file opened for reading.
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1477
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1478 Files have the following methods:
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1479
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1480
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1481 \begin{methoddesc}[file]{close}{}
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1482 Close the file. A closed file cannot be read or written any more.
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1483 Any operation which requires that the file be open will raise a
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1484 \exception{ValueError} after the file has been closed. Calling
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1485 \method{close()} more than once is allowed.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1486 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1487
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1488 \begin{methoddesc}[file]{flush}{}
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1489 Flush the internal buffer, like \code{stdio}'s
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1490 \cfunction{fflush()}. This may be a no-op on some file-like
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1491 objects.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1492 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1493
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1494 \begin{methoddesc}[file]{fileno}{}
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1495 \index{file descriptor}
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1496 \index{descriptor, file}
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1497 Return the integer ``file descriptor'' that is used by the
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1498 underlying implementation to request I/O operations from the
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1499 operating system. This can be useful for other, lower level
18416
33b4357aebb8 Fix up a few style nits -- avoid "e.g." and "i.e." -- these make
Fred Drake <fdrake@acm.org>
parents: 18395
diff changeset
1500 interfaces that use file descriptors, such as the
33b4357aebb8 Fix up a few style nits -- avoid "e.g." and "i.e." -- these make
Fred Drake <fdrake@acm.org>
parents: 18395
diff changeset
1501 \refmodule{fcntl}\refbimodindex{fcntl} module or
20580
376ee174ecd0 Use the \note and \warning macros where appropriate.
Fred Drake <fdrake@acm.org>
parents: 20173
diff changeset
1502 \function{os.read()} and friends. \note{File-like objects
18416
33b4357aebb8 Fix up a few style nits -- avoid "e.g." and "i.e." -- these make
Fred Drake <fdrake@acm.org>
parents: 18395
diff changeset
1503 which do not have a real file descriptor should \emph{not} provide
20580
376ee174ecd0 Use the \note and \warning macros where appropriate.
Fred Drake <fdrake@acm.org>
parents: 20173
diff changeset
1504 this method!}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1505 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1506
24599
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1507 \begin{methoddesc}[file]{isatty}{}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1508 Return \code{True} if the file is connected to a tty(-like) device, else
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1509 \code{False}. \note{If a file-like object is not associated
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1510 with a real file, this method should \emph{not} be implemented.}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1511 \end{methoddesc}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1512
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1513 \begin{methoddesc}[file]{next}{}
30413
53f1c32ee69d SF bug #804280: fromkeys is not listed in index
Raymond Hettinger <python@rcn.com>
parents: 30375
diff changeset
1514 A file object is its own iterator, for example \code{iter(\var{f})} returns
24599
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1515 \var{f} (unless \var{f} is closed). When a file is used as an
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1516 iterator, typically in a \keyword{for} loop (for example,
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1517 \code{for line in f: print line}), the \method{next()} method is
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1518 called repeatedly. This method returns the next input line, or raises
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1519 \exception{StopIteration} when \EOF{} is hit. In order to make a
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1520 \keyword{for} loop the most efficient way of looping over the lines of
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1521 a file (a very common operation), the \method{next()} method uses a
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1522 hidden read-ahead buffer. As a consequence of using a read-ahead
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1523 buffer, combining \method{next()} with other file methods (like
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1524 \method{readline()}) does not work right. However, using
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1525 \method{seek()} to reposition the file to an absolute position will
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1526 flush the read-ahead buffer.
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1527 \versionadded{2.3}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1528 \end{methoddesc}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1529
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1530 \begin{methoddesc}[file]{read}{\optional{size}}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1531 Read at most \var{size} bytes from the file (less if the read hits
10606
fe5fcb7e73f7 Correct documentation for <file>.read(); Python makes a serious
Fred Drake <fdrake@acm.org>
parents: 10520
diff changeset
1532 \EOF{} before obtaining \var{size} bytes). If the \var{size}
fe5fcb7e73f7 Correct documentation for <file>.read(); Python makes a serious
Fred Drake <fdrake@acm.org>
parents: 10520
diff changeset
1533 argument is negative or omitted, read all data until \EOF{} is
fe5fcb7e73f7 Correct documentation for <file>.read(); Python makes a serious
Fred Drake <fdrake@acm.org>
parents: 10520
diff changeset
1534 reached. The bytes are returned as a string object. An empty
fe5fcb7e73f7 Correct documentation for <file>.read(); Python makes a serious
Fred Drake <fdrake@acm.org>
parents: 10520
diff changeset
1535 string is returned when \EOF{} is encountered immediately. (For
fe5fcb7e73f7 Correct documentation for <file>.read(); Python makes a serious
Fred Drake <fdrake@acm.org>
parents: 10520
diff changeset
1536 certain files, like ttys, it makes sense to continue reading after
fe5fcb7e73f7 Correct documentation for <file>.read(); Python makes a serious
Fred Drake <fdrake@acm.org>
parents: 10520
diff changeset
1537 an \EOF{} is hit.) Note that this method may call the underlying
fe5fcb7e73f7 Correct documentation for <file>.read(); Python makes a serious
Fred Drake <fdrake@acm.org>
parents: 10520
diff changeset
1538 C function \cfunction{fread()} more than once in an effort to
26672
8dd25a6f5913 Fixed bug
Gustavo Niemeyer <gustavo@niemeyer.net>
parents: 26592
diff changeset
1539 acquire as close to \var{size} bytes as possible. Also note that
8dd25a6f5913 Fixed bug
Gustavo Niemeyer <gustavo@niemeyer.net>
parents: 26592
diff changeset
1540 when in non-blocking mode, less data than what was requested may
8dd25a6f5913 Fixed bug
Gustavo Niemeyer <gustavo@niemeyer.net>
parents: 26592
diff changeset
1541 be returned, even if no \var{size} parameter was given.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1542 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1543
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1544 \begin{methoddesc}[file]{readline}{\optional{size}}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1545 Read one entire line from the file. A trailing newline character is
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1546 kept in the string (but may be absent when a file ends with an
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1547 incomplete line).\footnote{
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1548 The advantage of leaving the newline on is that
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1549 returning an empty string is then an unambiguous \EOF{}
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1550 indication. It is also possible (in cases where it might
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1551 matter, for example, if you
22241
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1552 want to make an exact copy of a file while scanning its lines)
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1553 to tell whether the last line of a file ended in a newline
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
1554 or not (yes this happens!).
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1555 } If the \var{size} argument is present and
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1556 non-negative, it is a maximum byte count (including the trailing
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1557 newline) and an incomplete line may be returned.
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
1558 An empty string is returned \emph{only} when \EOF{} is encountered
20580
376ee174ecd0 Use the \note and \warning macros where appropriate.
Fred Drake <fdrake@acm.org>
parents: 20173
diff changeset
1559 immediately. \note{Unlike \code{stdio}'s \cfunction{fgets()}, the
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1560 returned string contains null characters (\code{'\e 0'}) if they
20580
376ee174ecd0 Use the \note and \warning macros where appropriate.
Fred Drake <fdrake@acm.org>
parents: 20173
diff changeset
1561 occurred in the input.}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1562 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1563
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1564 \begin{methoddesc}[file]{readlines}{\optional{sizehint}}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1565 Read until \EOF{} using \method{readline()} and return a list containing
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1566 the lines thus read. If the optional \var{sizehint} argument is
21062
bc02c3b09626 Clean up some markup cruft. A number of the macros that take no
Fred Drake <fdrake@acm.org>
parents: 20767
diff changeset
1567 present, instead of reading up to \EOF, whole lines totalling
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1568 approximately \var{sizehint} bytes (possibly after rounding up to an
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1569 internal buffer size) are read. Objects implementing a file-like
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1570 interface may choose to ignore \var{sizehint} if it cannot be
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1571 implemented, or cannot be implemented efficiently.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1572 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1573
15926
ac13cef423c8 Document xreadlines() method. (Forgot to check this in before!)
Guido van Rossum <guido@python.org>
parents: 15896
diff changeset
1574 \begin{methoddesc}[file]{xreadlines}{}
24599
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1575 This method returns the same thing as \code{iter(f)}.
17612
c19d6db6e99b Only document <file>.xreadlines() once; added version annotation.
Fred Drake <fdrake@acm.org>
parents: 17603
diff changeset
1576 \versionadded{2.1}
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1577 \deprecated{2.3}{Use \samp{for \var{line} in \var{file}} instead.}
15926
ac13cef423c8 Document xreadlines() method. (Forgot to check this in before!)
Guido van Rossum <guido@python.org>
parents: 15896
diff changeset
1578 \end{methoddesc}
ac13cef423c8 Document xreadlines() method. (Forgot to check this in before!)
Guido van Rossum <guido@python.org>
parents: 15896
diff changeset
1579
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1580 \begin{methoddesc}[file]{seek}{offset\optional{, whence}}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1581 Set the file's current position, like \code{stdio}'s \cfunction{fseek()}.
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1582 The \var{whence} argument is optional and defaults to \code{0}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1583 (absolute file positioning); other values are \code{1} (seek
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1584 relative to the current position) and \code{2} (seek relative to the
15731
a06415994cb5 Added information about the interaction of opening a file in append mode
Fred Drake <fdrake@acm.org>
parents: 15522
diff changeset
1585 file's end). There is no return value. Note that if the file is
a06415994cb5 Added information about the interaction of opening a file in append mode
Fred Drake <fdrake@acm.org>
parents: 15522
diff changeset
1586 opened for appending (mode \code{'a'} or \code{'a+'}), any
a06415994cb5 Added information about the interaction of opening a file in append mode
Fred Drake <fdrake@acm.org>
parents: 15522
diff changeset
1587 \method{seek()} operations will be undone at the next write. If the
a06415994cb5 Added information about the interaction of opening a file in append mode
Fred Drake <fdrake@acm.org>
parents: 15522
diff changeset
1588 file is only opened for writing in append mode (mode \code{'a'}),
a06415994cb5 Added information about the interaction of opening a file in append mode
Fred Drake <fdrake@acm.org>
parents: 15522
diff changeset
1589 this method is essentially a no-op, but it remains useful for files
30705
3ff03446f362 Patch #809535: Mention behaviour of seek on text files. Backported to 2.3.
Martin v. Löwis <martin@v.loewis.de>
parents: 30697
diff changeset
1590 opened in append mode with reading enabled (mode \code{'a+'}). If the
36038
64c6ab5671e7 Remove reference to open() mode "t" as it is platform dependent.
Georg Brandl <georg@python.org>
parents: 35952
diff changeset
1591 file is opened in text mode (without \code{'b'}), only offsets returned
30705
3ff03446f362 Patch #809535: Mention behaviour of seek on text files. Backported to 2.3.
Martin v. Löwis <martin@v.loewis.de>
parents: 30697
diff changeset
1592 by \method{tell()} are legal. Use of other offsets causes undefined
3ff03446f362 Patch #809535: Mention behaviour of seek on text files. Backported to 2.3.
Martin v. Löwis <martin@v.loewis.de>
parents: 30697
diff changeset
1593 behavior.
3ff03446f362 Patch #809535: Mention behaviour of seek on text files. Backported to 2.3.
Martin v. Löwis <martin@v.loewis.de>
parents: 30697
diff changeset
1594
3ff03446f362 Patch #809535: Mention behaviour of seek on text files. Backported to 2.3.
Martin v. Löwis <martin@v.loewis.de>
parents: 30697
diff changeset
1595 Note that not all file objects are seekable.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1596 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1597
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1598 \begin{methoddesc}[file]{tell}{}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1599 Return the file's current position, like \code{stdio}'s
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1600 \cfunction{ftell()}.
36334
98faac1df5bb Bug #1396471: Document that Windows' ftell() can return invalid
Georg Brandl <georg@python.org>
parents: 36167
diff changeset
1601
98faac1df5bb Bug #1396471: Document that Windows' ftell() can return invalid
Georg Brandl <georg@python.org>
parents: 36167
diff changeset
1602 \note{On Windows, \method{tell()} can return illegal values (after an
98faac1df5bb Bug #1396471: Document that Windows' ftell() can return invalid
Georg Brandl <georg@python.org>
parents: 36167
diff changeset
1603 \cfunction{fgets()}) when reading files with \UNIX{}-style line-endings.
98faac1df5bb Bug #1396471: Document that Windows' ftell() can return invalid
Georg Brandl <georg@python.org>
parents: 36167
diff changeset
1604 Use binary mode (\code{'rb'}) to circumvent this problem.}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1605 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1606
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1607 \begin{methoddesc}[file]{truncate}{\optional{size}}
22241
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1608 Truncate the file's size. If the optional \var{size} argument is
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1609 present, the file is truncated to (at most) that size. The size
22241
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1610 defaults to the current position. The current file position is
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1611 not changed. Note that if a specified size exceeds the file's
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1612 current size, the result is platform-dependent: possibilities
36167
834dd664aefc Bug #1394868: doc typos
Georg Brandl <georg@python.org>
parents: 36136
diff changeset
1613 include that the file may remain unchanged, increase to the specified
22241
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1614 size as if zero-filled, or increase to the specified size with
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1615 undefined new content.
30375
4aa84a8b1fe4 Fix spacing markup and other sundries.
Raymond Hettinger <python@rcn.com>
parents: 30250
diff changeset
1616 Availability: Windows, many \UNIX{} variants.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1617 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1618
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1619 \begin{methoddesc}[file]{write}{str}
20580
376ee174ecd0 Use the \note and \warning macros where appropriate.
Fred Drake <fdrake@acm.org>
parents: 20173
diff changeset
1620 Write a string to the file. There is no return value. Due to
15789
9e9556924b0a Added documentation for the xreadlines module & related changes. The
Fred Drake <fdrake@acm.org>
parents: 15731
diff changeset
1621 buffering, the string may not actually show up in the file until
9e9556924b0a Added documentation for the xreadlines module & related changes. The
Fred Drake <fdrake@acm.org>
parents: 15731
diff changeset
1622 the \method{flush()} or \method{close()} method is called.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1623 \end{methoddesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1624
20045
7b8c11739714 Generalize file.writelines() to allow iterable objects.
Tim Peters <tim.peters@gmail.com>
parents: 20031
diff changeset
1625 \begin{methoddesc}[file]{writelines}{sequence}
7b8c11739714 Generalize file.writelines() to allow iterable objects.
Tim Peters <tim.peters@gmail.com>
parents: 20031
diff changeset
1626 Write a sequence of strings to the file. The sequence can be any
7b8c11739714 Generalize file.writelines() to allow iterable objects.
Tim Peters <tim.peters@gmail.com>
parents: 20031
diff changeset
1627 iterable object producing strings, typically a list of strings.
7b8c11739714 Generalize file.writelines() to allow iterable objects.
Tim Peters <tim.peters@gmail.com>
parents: 20031
diff changeset
1628 There is no return value.
15789
9e9556924b0a Added documentation for the xreadlines module & related changes. The
Fred Drake <fdrake@acm.org>
parents: 15731
diff changeset
1629 (The name is intended to match \method{readlines()};
9e9556924b0a Added documentation for the xreadlines module & related changes. The
Fred Drake <fdrake@acm.org>
parents: 15731
diff changeset
1630 \method{writelines()} does not add line separators.)
9e9556924b0a Added documentation for the xreadlines module & related changes. The
Fred Drake <fdrake@acm.org>
parents: 15731
diff changeset
1631 \end{methoddesc}
9e9556924b0a Added documentation for the xreadlines module & related changes. The
Fred Drake <fdrake@acm.org>
parents: 15731
diff changeset
1632
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1633
20031
e5a3f9d7766b Note that files are iterable; describe what the iterator returns.
Fred Drake <fdrake@acm.org>
parents: 19529
diff changeset
1634 Files support the iterator protocol. Each iteration returns the same
e5a3f9d7766b Note that files are iterable; describe what the iterator returns.
Fred Drake <fdrake@acm.org>
parents: 19529
diff changeset
1635 result as \code{\var{file}.readline()}, and iteration ends when the
e5a3f9d7766b Note that files are iterable; describe what the iterator returns.
Fred Drake <fdrake@acm.org>
parents: 19529
diff changeset
1636 \method{readline()} method returns an empty string.
e5a3f9d7766b Note that files are iterable; describe what the iterator returns.
Fred Drake <fdrake@acm.org>
parents: 19529
diff changeset
1637
e5a3f9d7766b Note that files are iterable; describe what the iterator returns.
Fred Drake <fdrake@acm.org>
parents: 19529
diff changeset
1638
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1639 File objects also offer a number of other interesting attributes.
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1640 These are not required for file-like objects, but should be
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1641 implemented if they make sense for the particular object.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1642
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1643 \begin{memberdesc}[file]{closed}
22920
2392af05f052 Update docs for bool changes by Guido around April 6
Neal Norwitz <nnorwitz@gmail.com>
parents: 22785
diff changeset
1644 bool indicating the current state of the file object. This is a
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1645 read-only attribute; the \method{close()} method changes the value.
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1646 It may not be available on all file-like objects.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1647 \end{memberdesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1648
29065
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1649 \begin{memberdesc}[file]{encoding}
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1650 The encoding that this file uses. When Unicode strings are written
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1651 to a file, they will be converted to byte strings using this encoding.
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1652 In addition, when the file is connected to a terminal, the attribute
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1653 gives the encoding that the terminal is likely to use (that
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1654 information might be incorrect if the user has misconfigured the
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1655 terminal). The attribute is read-only and may not be present on
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1656 all file-like objects. It may also be \code{None}, in which case
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1657 the file uses the system default encoding for converting Unicode
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1658 strings.
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1659
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1660 \versionadded{2.3}
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1661 \end{memberdesc}
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1662
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1663 \begin{memberdesc}[file]{mode}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1664 The I/O mode for the file. If the file was created using the
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1665 \function{open()} built-in function, this will be the value of the
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1666 \var{mode} parameter. This is a read-only attribute and may not be
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1667 present on all file-like objects.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1668 \end{memberdesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1669
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1670 \begin{memberdesc}[file]{name}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1671 If the file object was created using \function{open()}, the name of
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1672 the file. Otherwise, some string that indicates the source of the
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1673 file object, of the form \samp{<\mbox{\ldots}>}. This is a read-only
14685
faf3e734254d Clarify a number of issues about the file-like object API based on
Fred Drake <fdrake@acm.org>
parents: 14557
diff changeset
1674 attribute and may not be present on all file-like objects.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1675 \end{memberdesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1676
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1677 \begin{memberdesc}[file]{newlines}
31282
8b62f4194a7e markup fix
Fred Drake <fdrake@acm.org>
parents: 31210
diff changeset
1678 If Python was built with the \longprogramopt{with-universal-newlines}
8b62f4194a7e markup fix
Fred Drake <fdrake@acm.org>
parents: 31210
diff changeset
1679 option to \program{configure} (the default) this read-only attribute
8b62f4194a7e markup fix
Fred Drake <fdrake@acm.org>
parents: 31210
diff changeset
1680 exists, and for files opened in
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1681 universal newline read mode it keeps track of the types of newlines
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1682 encountered while reading the file. The values it can take are
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1683 \code{'\e r'}, \code{'\e n'}, \code{'\e r\e n'}, \code{None} (unknown,
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1684 no newlines read yet) or a tuple containing all the newline
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1685 types seen, to indicate that multiple
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1686 newline conventions were encountered. For files not opened in universal
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1687 newline read mode the value of this attribute will be \code{None}.
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1688 \end{memberdesc}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1689
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1690 \begin{memberdesc}[file]{softspace}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1691 Boolean that indicates whether a space character needs to be printed
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1692 before another value when using the \keyword{print} statement.
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1693 Classes that are trying to simulate a file object should also have a
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1694 writable \member{softspace} attribute, which should be initialized to
14485
ac0246586d52 Improve a couple of references to the language reference, making them
Fred Drake <fdrake@acm.org>
parents: 14044
diff changeset
1695 zero. This will be automatic for most classes implemented in Python
ac0246586d52 Improve a couple of references to the language reference, making them
Fred Drake <fdrake@acm.org>
parents: 14044
diff changeset
1696 (care may be needed for objects that override attribute access); types
ac0246586d52 Improve a couple of references to the language reference, making them
Fred Drake <fdrake@acm.org>
parents: 14044
diff changeset
1697 implemented in C will have to provide a writable
ac0246586d52 Improve a couple of references to the language reference, making them
Fred Drake <fdrake@acm.org>
parents: 14044
diff changeset
1698 \member{softspace} attribute.
20580
376ee174ecd0 Use the \note and \warning macros where appropriate.
Fred Drake <fdrake@acm.org>
parents: 20173
diff changeset
1699 \note{This attribute is not used to control the
14705
4712f5b8f279 Clarify that the softspace attribute is used by print for state management,
Fred Drake <fdrake@acm.org>
parents: 14685
diff changeset
1700 \keyword{print} statement, but to allow the implementation of
20580
376ee174ecd0 Use the \note and \warning macros where appropriate.
Fred Drake <fdrake@acm.org>
parents: 20173
diff changeset
1701 \keyword{print} to keep track of its internal state.}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1702 \end{memberdesc}
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1703
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1704
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1705 \subsection{Other Built-in Types \label{typesother}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1706
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1707 The interpreter supports several other kinds of objects.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1708 Most of these support only one or two operations.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1709
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1710
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1711 \subsubsection{Modules \label{typesmodules}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1712
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1713 The only special operation on a module is attribute access:
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1714 \code{\var{m}.\var{name}}, where \var{m} is a module and \var{name}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1715 accesses a name defined in \var{m}'s symbol table. Module attributes
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1716 can be assigned to. (Note that the \keyword{import} statement is not,
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1717 strictly speaking, an operation on a module object; \code{import
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1718 \var{foo}} does not require a module object named \var{foo} to exist,
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1719 rather it requires an (external) \emph{definition} for a module named
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1720 \var{foo} somewhere.)
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1721
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1722 A special member of every module is \member{__dict__}.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1723 This is the dictionary containing the module's symbol table.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1724 Modifying this dictionary will actually change the module's symbol
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1725 table, but direct assignment to the \member{__dict__} attribute is not
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1726 possible (you can write \code{\var{m}.__dict__['a'] = 1}, which
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1727 defines \code{\var{m}.a} to be \code{1}, but you can't write
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1728 \code{\var{m}.__dict__ = \{\}}). Modifying \member{__dict__} directly
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1729 is not recommended.
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1730
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1731 Modules built into the interpreter are written like this:
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1732 \code{<module 'sys' (built-in)>}. If loaded from a file, they are
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1733 written as \code{<module 'os' from
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1734 '/usr/local/lib/python\shortversion/os.pyc'>}.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1735
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1736
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1737 \subsubsection{Classes and Class Instances \label{typesobjects}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1738 \nodename{Classes and Instances}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1739
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1740 See chapters 3 and 7 of the \citetitle[../ref/ref.html]{Python
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1741 Reference Manual} for these.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1742
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1743
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1744 \subsubsection{Functions \label{typesfunctions}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1745
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1746 Function objects are created by function definitions. The only
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1747 operation on a function object is to call it:
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1748 \code{\var{func}(\var{argument-list})}.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1749
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1750 There are really two flavors of function objects: built-in functions
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1751 and user-defined functions. Both support the same operation (to call
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1752 the function), but the implementation is different, hence the
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1753 different object types.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1754
33102
f27935b46985 This is my patch
Michael W. Hudson <mwh@python.net>
parents: 33003
diff changeset
1755 See the \citetitle[../ref/ref.html]{Python Reference Manual} for more
f27935b46985 This is my patch
Michael W. Hudson <mwh@python.net>
parents: 33003
diff changeset
1756 information.
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1757
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1758 \subsubsection{Methods \label{typesmethods}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1759 \obindex{method}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1760
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1761 Methods are functions that are called using the attribute notation.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1762 There are two flavors: built-in methods (such as \method{append()} on
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1763 lists) and class instance methods. Built-in methods are described
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1764 with the types that support them.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1765
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1766 The implementation adds two special read-only attributes to class
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1767 instance methods: \code{\var{m}.im_self} is the object on which the
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1768 method operates, and \code{\var{m}.im_func} is the function
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1769 implementing the method. Calling \code{\var{m}(\var{arg-1},
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1770 \var{arg-2}, \textrm{\ldots}, \var{arg-n})} is completely equivalent to
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1771 calling \code{\var{m}.im_func(\var{m}.im_self, \var{arg-1},
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1772 \var{arg-2}, \textrm{\ldots}, \var{arg-n})}.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1773
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1774 Class instance methods are either \emph{bound} or \emph{unbound},
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1775 referring to whether the method was accessed through an instance or a
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1776 class, respectively. When a method is unbound, its \code{im_self}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1777 attribute will be \code{None} and if called, an explicit \code{self}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1778 object must be passed as the first argument. In this case,
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1779 \code{self} must be an instance of the unbound method's class (or a
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1780 subclass of that class), otherwise a \code{TypeError} is raised.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1781
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1782 Like function objects, methods objects support getting
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1783 arbitrary attributes. However, since method attributes are actually
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1784 stored on the underlying function object (\code{meth.im_func}),
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1785 setting method attributes on either bound or unbound methods is
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1786 disallowed. Attempting to set a method attribute results in a
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1787 \code{TypeError} being raised. In order to set a method attribute,
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1788 you need to explicitly set it on the underlying function object:
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1789
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1790 \begin{verbatim}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1791 class C:
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1792 def method(self):
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1793 pass
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1794
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1795 c = C()
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1796 c.method.im_func.whoami = 'my name is c'
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1797 \end{verbatim}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1798
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1799 See the \citetitle[../ref/ref.html]{Python Reference Manual} for more
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1800 information.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1801
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1802
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1803 \subsubsection{Code Objects \label{bltin-code-objects}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1804 \obindex{code}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1805
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1806 Code objects are used by the implementation to represent
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1807 ``pseudo-compiled'' executable Python code such as a function body.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1808 They differ from function objects because they don't contain a
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1809 reference to their global execution environment. Code objects are
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1810 returned by the built-in \function{compile()} function and can be
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1811 extracted from function objects through their \member{func_code}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1812 attribute.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1813 \bifuncindex{compile}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1814 \withsubitem{(function object attribute)}{\ttindex{func_code}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1815
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1816 A code object can be executed or evaluated by passing it (instead of a
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1817 source string) to the \keyword{exec} statement or the built-in
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1818 \function{eval()} function.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1819 \stindex{exec}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1820 \bifuncindex{eval}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1821
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1822 See the \citetitle[../ref/ref.html]{Python Reference Manual} for more
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1823 information.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1824
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1825
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1826 \subsubsection{Type Objects \label{bltin-type-objects}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1827
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1828 Type objects represent the various object types. An object's type is
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1829 accessed by the built-in function \function{type()}. There are no special
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1830 operations on types. The standard module \refmodule{types} defines names
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1831 for all standard built-in types.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1832 \bifuncindex{type}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1833 \refstmodindex{types}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1834
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1835 Types are written like this: \code{<type 'int'>}.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1836
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1837
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1838 \subsubsection{The Null Object \label{bltin-null-object}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1839
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1840 This object is returned by functions that don't explicitly return a
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1841 value. It supports no special operations. There is exactly one null
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1842 object, named \code{None} (a built-in name).
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1843
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1844 It is written as \code{None}.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1845
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1846
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1847 \subsubsection{The Ellipsis Object \label{bltin-ellipsis-object}}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1848
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1849 This object is used by extended slice notation (see the
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1850 \citetitle[../ref/ref.html]{Python Reference Manual}). It supports no
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1851 special operations. There is exactly one ellipsis object, named
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1852 \constant{Ellipsis} (a built-in name).
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1853
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1854 It is written as \code{Ellipsis}.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1855
22785
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1856 \subsubsection{Boolean Values}
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1857
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1858 Boolean values are the two constant objects \code{False} and
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1859 \code{True}. They are used to represent truth values (although other
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1860 values can also be considered false or true). In numeric contexts
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1861 (for example when used as the argument to an arithmetic operator),
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1862 they behave like the integers 0 and 1, respectively. The built-in
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1863 function \function{bool()} can be used to cast any value to a Boolean,
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1864 if the value can be interpreted as a truth value (see section Truth
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1865 Value Testing above).
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1866
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1867 They are written as \code{False} and \code{True}, respectively.
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1868 \index{False}
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1869 \index{True}
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1870 \indexii{Boolean}{values}
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1871
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1872
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1873 \subsubsection{Internal Objects \label{typesinternal}}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1874
11463
17e12305973e Use \citetitle and \programopt as appropriate.
Fred Drake <fdrake@acm.org>
parents: 11183
diff changeset
1875 See the \citetitle[../ref/ref.html]{Python Reference Manual} for this
14044
a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange()
Fred Drake <fdrake@acm.org>
parents: 13967
diff changeset
1876 information. It describes stack frame objects, traceback objects, and
a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange()
Fred Drake <fdrake@acm.org>
parents: 13967
diff changeset
1877 slice objects.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1878
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1879
9083
bc41e86c938c Markup nits.
Fred Drake <fdrake@acm.org>
parents: 9034
diff changeset
1880 \subsection{Special Attributes \label{specialattrs}}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1881
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1882 The implementation adds a few special read-only attributes to several
32070
b319db3869d8 add note about the __name__ read-only attribute
Fred Drake <fdrake@acm.org>
parents: 31631
diff changeset
1883 object types, where they are relevant. Some of these are not reported
b319db3869d8 add note about the __name__ read-only attribute
Fred Drake <fdrake@acm.org>
parents: 31631
diff changeset
1884 by the \function{dir()} built-in function.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1885
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1886 \begin{memberdesc}[object]{__dict__}
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1887 A dictionary or other mapping object used to store an
9083
bc41e86c938c Markup nits.
Fred Drake <fdrake@acm.org>
parents: 9034
diff changeset
1888 object's (writable) attributes.
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1889 \end{memberdesc}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1890
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1891 \begin{memberdesc}[object]{__methods__}
21159
6fa96b329e15 Remove most references to __members__ and __methods__, leaving only one pair
Fred Drake <fdrake@acm.org>
parents: 21062
diff changeset
1892 \deprecated{2.2}{Use the built-in function \function{dir()} to get a
6fa96b329e15 Remove most references to __members__ and __methods__, leaving only one pair
Fred Drake <fdrake@acm.org>
parents: 21062
diff changeset
1893 list of an object's attributes. This attribute is no longer available.}
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1894 \end{memberdesc}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1895
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1896 \begin{memberdesc}[object]{__members__}
21159
6fa96b329e15 Remove most references to __members__ and __methods__, leaving only one pair
Fred Drake <fdrake@acm.org>
parents: 21062
diff changeset
1897 \deprecated{2.2}{Use the built-in function \function{dir()} to get a
6fa96b329e15 Remove most references to __members__ and __methods__, leaving only one pair
Fred Drake <fdrake@acm.org>
parents: 21062
diff changeset
1898 list of an object's attributes. This attribute is no longer available.}
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1899 \end{memberdesc}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1900
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1901 \begin{memberdesc}[instance]{__class__}
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1902 The class to which a class instance belongs.
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1903 \end{memberdesc}
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1904
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1905 \begin{memberdesc}[class]{__bases__}
18416
33b4357aebb8 Fix up a few style nits -- avoid "e.g." and "i.e." -- these make
Fred Drake <fdrake@acm.org>
parents: 18395
diff changeset
1906 The tuple of base classes of a class object. If there are no base
33b4357aebb8 Fix up a few style nits -- avoid "e.g." and "i.e." -- these make
Fred Drake <fdrake@acm.org>
parents: 18395
diff changeset
1907 classes, this will be an empty tuple.
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1908 \end{memberdesc}
32070
b319db3869d8 add note about the __name__ read-only attribute
Fred Drake <fdrake@acm.org>
parents: 31631
diff changeset
1909
b319db3869d8 add note about the __name__ read-only attribute
Fred Drake <fdrake@acm.org>
parents: 31631
diff changeset
1910 \begin{memberdesc}[class]{__name__}
b319db3869d8 add note about the __name__ read-only attribute
Fred Drake <fdrake@acm.org>
parents: 31631
diff changeset
1911 The name of the class or type.
b319db3869d8 add note about the __name__ read-only attribute
Fred Drake <fdrake@acm.org>
parents: 31631
diff changeset
1912 \end{memberdesc}