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Typo fix; use 'in-place' instead of 'inplace'
author Andrew M. Kuchling <amk@amk.ca>
date Fri, 06 Aug 2004 18:55:09 +0000
parents fb6ffd290cfb
children b5dcfe7a4159
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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 \label{boolean}}
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76
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77 These are the Boolean operations, ordered by ascending priority:
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78 \indexii{Boolean}{operations}
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79
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80 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
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81 \lineiii{\var{x} or \var{y}}
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82 {if \var{x} is false, then \var{y}, else \var{x}}{(1)}
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83 \lineiii{\var{x} and \var{y}}
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84 {if \var{x} is false, then \var{x}, else \var{y}}{(1)}
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85 \hline
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86 \lineiii{not \var{x}}
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87 {if \var{x} is false, then \code{True}, else \code{False}}{(2)}
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88 \end{tableiii}
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89 \opindex{and}
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90 \opindex{or}
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91 \opindex{not}
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92
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93 \noindent
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94 Notes:
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95
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96 \begin{description}
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97
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98 \item[(1)]
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99 These only evaluate their second argument if needed for their outcome.
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100
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101 \item[(2)]
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102 \samp{not} has a lower priority than non-Boolean operators, so
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103 \code{not \var{a} == \var{b}} is interpreted as \code{not (\var{a} ==
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104 \var{b})}, and \code{\var{a} == not \var{b}} is a syntax error.
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105
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106 \end{description}
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107
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108
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109 \subsection{Comparisons \label{comparisons}}
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110
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111 Comparison operations are supported by all objects. They all have the
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112 same priority (which is higher than that of the Boolean operations).
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113 Comparisons can be chained arbitrarily; for example, \code{\var{x} <
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114 \var{y} <= \var{z}} is equivalent to \code{\var{x} < \var{y} and
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115 \var{y} <= \var{z}}, except that \var{y} is evaluated only once (but
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116 in both cases \var{z} is not evaluated at all when \code{\var{x} <
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117 \var{y}} is found to be false).
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118 \indexii{chaining}{comparisons}
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119
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120 This table summarizes the comparison operations:
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121
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122 \begin{tableiii}{c|l|c}{code}{Operation}{Meaning}{Notes}
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123 \lineiii{<}{strictly less than}{}
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124 \lineiii{<=}{less than or equal}{}
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125 \lineiii{>}{strictly greater than}{}
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126 \lineiii{>=}{greater than or equal}{}
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127 \lineiii{==}{equal}{}
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128 \lineiii{!=}{not equal}{(1)}
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129 \lineiii{<>}{not equal}{(1)}
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130 \lineiii{is}{object identity}{}
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131 \lineiii{is not}{negated object identity}{}
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132 \end{tableiii}
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133 \indexii{operator}{comparison}
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134 \opindex{==} % XXX *All* others have funny characters < ! >
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135 \opindex{is}
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136 \opindex{is not}
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137
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138 \noindent
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139 Notes:
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140
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141 \begin{description}
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142
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143 \item[(1)]
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144 \code{<>} and \code{!=} are alternate spellings for the same operator.
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145 \code{!=} is the preferred spelling; \code{<>} is obsolescent.
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146
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147 \end{description}
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148
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149 Objects of different types, except different numeric types and different string types, never
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150 compare equal; such objects are ordered consistently but arbitrarily
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151 (so that sorting a heterogeneous array yields a consistent result).
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152 Furthermore, some types (for example, file objects) support only a
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153 degenerate notion of comparison where any two objects of that type are
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154 unequal. Again, such objects are ordered arbitrarily but
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155 consistently. The \code{<}, \code{<=}, \code{>} and \code{>=}
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156 operators will raise a \exception{TypeError} exception when any operand
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157 is a complex number.
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158 \indexii{object}{numeric}
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159 \indexii{objects}{comparing}
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160
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161 Instances of a class normally compare as non-equal unless the class
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162 \withsubitem{(instance method)}{\ttindex{__cmp__()}}
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163 defines the \method{__cmp__()} method. Refer to the
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164 \citetitle[../ref/customization.html]{Python Reference Manual} for
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165 information on the use of this method to effect object comparisons.
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166
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167 \strong{Implementation note:} Objects of different types except
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168 numbers are ordered by their type names; objects of the same types
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169 that don't support proper comparison are ordered by their address.
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170
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171 Two more operations with the same syntactic priority,
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172 \samp{in}\opindex{in} and \samp{not in}\opindex{not in}, are supported
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173 only by sequence types (below).
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174
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175
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176 \subsection{Numeric Types \label{typesnumeric}}
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177
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178 There are four distinct numeric types: \dfn{plain integers},
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179 \dfn{long integers},
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180 \dfn{floating point numbers}, and \dfn{complex numbers}.
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181 In addition, Booleans are a subtype of plain integers.
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182 Plain integers (also just called \dfn{integers})
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183 are implemented using \ctype{long} in C, which gives them at least 32
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184 bits of precision. Long integers have unlimited precision. Floating
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185 point numbers are implemented using \ctype{double} in C. All bets on
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186 their precision are off unless you happen to know the machine you are
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187 working with.
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188 \obindex{numeric}
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189 \obindex{Boolean}
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190 \obindex{integer}
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191 \obindex{long integer}
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192 \obindex{floating point}
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193 \obindex{complex number}
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194 \indexii{C}{language}
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195
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196 Complex numbers have a real and imaginary part, which are each
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197 implemented using \ctype{double} in C. To extract these parts from
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198 a complex number \var{z}, use \code{\var{z}.real} and \code{\var{z}.imag}.
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199
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200 Numbers are created by numeric literals or as the result of built-in
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201 functions and operators. Unadorned integer literals (including hex
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202 and octal numbers) yield plain integers unless the value they denote
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203 is too large to be represented as a plain integer, in which case
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204 they yield a long integer. Integer literals with an
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205 \character{L} or \character{l} suffix yield long integers
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206 (\character{L} is preferred because \samp{1l} looks too much like
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207 eleven!). Numeric literals containing a decimal point or an exponent
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208 sign yield floating point numbers. Appending \character{j} or
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209 \character{J} to a numeric literal yields a complex number with a
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210 zero real part. A complex numeric literal is the sum of a real and
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211 an imaginary part.
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212 \indexii{numeric}{literals}
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213 \indexii{integer}{literals}
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214 \indexiii{long}{integer}{literals}
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215 \indexii{floating point}{literals}
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216 \indexii{complex number}{literals}
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217 \indexii{hexadecimal}{literals}
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218 \indexii{octal}{literals}
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219
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220 Python fully supports mixed arithmetic: when a binary arithmetic
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221 operator has operands of different numeric types, the operand with the
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222 ``narrower'' type is widened to that of the other, where plain
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223 integer is narrower than long integer is narrower than floating point is
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224 narrower than complex.
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225 Comparisons between numbers of mixed type use the same rule.\footnote{
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226 As a consequence, the list \code{[1, 2]} is considered equal
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227 to \code{[1.0, 2.0]}, and similarly for tuples.
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228 } The constructors \function{int()}, \function{long()}, \function{float()},
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229 and \function{complex()} can be used
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230 to produce numbers of a specific type.
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231 \index{arithmetic}
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232 \bifuncindex{int}
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233 \bifuncindex{long}
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234 \bifuncindex{float}
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235 \bifuncindex{complex}
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236
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237 All numeric types (except complex) support the following operations,
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238 sorted by ascending priority (operations in the same box have the same
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239 priority; all numeric operations have a higher priority than
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240 comparison operations):
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241
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242 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
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243 \lineiii{\var{x} + \var{y}}{sum of \var{x} and \var{y}}{}
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244 \lineiii{\var{x} - \var{y}}{difference of \var{x} and \var{y}}{}
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245 \hline
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246 \lineiii{\var{x} * \var{y}}{product of \var{x} and \var{y}}{}
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247 \lineiii{\var{x} / \var{y}}{quotient of \var{x} and \var{y}}{(1)}
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248 \lineiii{\var{x} \%{} \var{y}}{remainder of \code{\var{x} / \var{y}}}{(4)}
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249 \hline
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250 \lineiii{-\var{x}}{\var{x} negated}{}
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251 \lineiii{+\var{x}}{\var{x} unchanged}{}
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252 \hline
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253 \lineiii{abs(\var{x})}{absolute value or magnitude of \var{x}}{}
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254 \lineiii{int(\var{x})}{\var{x} converted to integer}{(2)}
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255 \lineiii{long(\var{x})}{\var{x} converted to long integer}{(2)}
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256 \lineiii{float(\var{x})}{\var{x} converted to floating point}{}
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257 \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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258 \lineiii{\var{c}.conjugate()}{conjugate of the complex number \var{c}}{}
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259 \lineiii{divmod(\var{x}, \var{y})}{the pair \code{(\var{x} / \var{y}, \var{x} \%{} \var{y})}}{(3)(4)}
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260 \lineiii{pow(\var{x}, \var{y})}{\var{x} to the power \var{y}}{}
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261 \lineiii{\var{x} ** \var{y}}{\var{x} to the power \var{y}}{}
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262 \end{tableiii}
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263 \indexiii{operations on}{numeric}{types}
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264 \withsubitem{(complex number method)}{\ttindex{conjugate()}}
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265
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266 \noindent
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267 Notes:
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268 \begin{description}
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269
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270 \item[(1)]
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271 For (plain or long) integer division, the result is an integer.
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272 The result is always rounded towards minus infinity: 1/2 is 0,
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273 (-1)/2 is -1, 1/(-2) is -1, and (-1)/(-2) is 0. Note that the result
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274 is a long integer if either operand is a long integer, regardless of
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275 the numeric value.
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276 \indexii{integer}{division}
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277 \indexiii{long}{integer}{division}
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278
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279 \item[(2)]
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280 Conversion from floating point to (long or plain) integer may round or
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281 truncate as in C; see functions \function{floor()} and
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282 \function{ceil()} in the \refmodule{math}\refbimodindex{math} module
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283 for well-defined conversions.
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284 \withsubitem{(in module math)}{\ttindex{floor()}\ttindex{ceil()}}
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285 \indexii{numeric}{conversions}
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286 \indexii{C}{language}
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287
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288 \item[(3)]
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289 See section \ref{built-in-funcs}, ``Built-in Functions,'' for a full
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290 description.
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291
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292 \item[(4)]
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293 Complex floor division operator, modulo operator, and \function{divmod()}.
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294
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295 \deprecated{2.3}{Instead convert to float using \function{abs()}
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296 if appropriate.}
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297
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298 \end{description}
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299 % XXXJH exceptions: overflow (when? what operations?) zerodivision
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300
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301 \subsubsection{Bit-string Operations on Integer Types \label{bitstring-ops}}
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302 \nodename{Bit-string Operations}
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303
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304 Plain and long integer types support additional operations that make
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305 sense only for bit-strings. Negative numbers are treated as their 2's
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306 complement value (for long integers, this assumes a sufficiently large
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307 number of bits that no overflow occurs during the operation).
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308
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309 The priorities of the binary bit-wise operations are all lower than
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310 the numeric operations and higher than the comparisons; the unary
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311 operation \samp{\~} has the same priority as the other unary numeric
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312 operations (\samp{+} and \samp{-}).
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313
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314 This table lists the bit-string operations sorted in ascending
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315 priority (operations in the same box have the same priority):
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316
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317 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
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318 \lineiii{\var{x} | \var{y}}{bitwise \dfn{or} of \var{x} and \var{y}}{}
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319 \lineiii{\var{x} \^{} \var{y}}{bitwise \dfn{exclusive or} of \var{x} and \var{y}}{}
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320 \lineiii{\var{x} \&{} \var{y}}{bitwise \dfn{and} of \var{x} and \var{y}}{}
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321 \lineiii{\var{x} << \var{n}}{\var{x} shifted left by \var{n} bits}{(1), (2)}
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322 \lineiii{\var{x} >> \var{n}}{\var{x} shifted right by \var{n} bits}{(1), (3)}
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323 \hline
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324 \lineiii{\~\var{x}}{the bits of \var{x} inverted}{}
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325 \end{tableiii}
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326 \indexiii{operations on}{integer}{types}
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327 \indexii{bit-string}{operations}
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328 \indexii{shifting}{operations}
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329 \indexii{masking}{operations}
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330
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331 \noindent
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332 Notes:
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333 \begin{description}
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334 \item[(1)] Negative shift counts are illegal and cause a
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335 \exception{ValueError} to be raised.
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336 \item[(2)] A left shift by \var{n} bits is equivalent to
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337 multiplication by \code{pow(2, \var{n})} without overflow check.
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338 \item[(3)] A right shift by \var{n} bits is equivalent to
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339 division by \code{pow(2, \var{n})} without overflow check.
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340 \end{description}
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341
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342
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343 \subsection{Iterator Types \label{typeiter}}
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344
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345 \versionadded{2.2}
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346 \index{iterator protocol}
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347 \index{protocol!iterator}
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348 \index{sequence!iteration}
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349 \index{container!iteration over}
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350
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351 Python supports a concept of iteration over containers. This is
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352 implemented using two distinct methods; these are used to allow
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353 user-defined classes to support iteration. Sequences, described below
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354 in more detail, always support the iteration methods.
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355
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356 One method needs to be defined for container objects to provide
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357 iteration support:
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358
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359 \begin{methoddesc}[container]{__iter__}{}
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360 Return an iterator object. The object is required to support the
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361 iterator protocol described below. If a container supports
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362 different types of iteration, additional methods can be provided to
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363 specifically request iterators for those iteration types. (An
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364 example of an object supporting multiple forms of iteration would be
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365 a tree structure which supports both breadth-first and depth-first
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366 traversal.) This method corresponds to the \member{tp_iter} slot of
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367 the type structure for Python objects in the Python/C API.
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368 \end{methoddesc}
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369
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370 The iterator objects themselves are required to support the following
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371 two methods, which together form the \dfn{iterator protocol}:
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372
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373 \begin{methoddesc}[iterator]{__iter__}{}
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374 Return the iterator object itself. This is required to allow both
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375 containers and iterators to be used with the \keyword{for} and
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376 \keyword{in} statements. This method corresponds to the
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377 \member{tp_iter} slot of the type structure for Python objects in
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378 the Python/C API.
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379 \end{methoddesc}
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380
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381 \begin{methoddesc}[iterator]{next}{}
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382 Return the next item from the container. If there are no further
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383 items, raise the \exception{StopIteration} exception. This method
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384 corresponds to the \member{tp_iternext} slot of the type structure
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385 for Python objects in the Python/C API.
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386 \end{methoddesc}
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387
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388 Python defines several iterator objects to support iteration over
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389 general and specific sequence types, dictionaries, and other more
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390 specialized forms. The specific types are not important beyond their
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391 implementation of the iterator protocol.
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392
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393 The intention of the protocol is that once an iterator's
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394 \method{next()} method raises \exception{StopIteration}, it will
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395 continue to do so on subsequent calls. Implementations that
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396 do not obey this property are deemed broken. (This constraint
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397 was added in Python 2.3; in Python 2.2, various iterators are
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398 broken according to this rule.)
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399
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400 Python's generators provide a convenient way to implement the
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401 iterator protocol. If a container object's \method{__iter__()}
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402 method is implemented as a generator, it will automatically
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403 return an iterator object (technically, a generator object)
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parents: 29516
diff changeset
404 supplying the \method{__iter__()} and \method{next()} methods.
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parents: 29516
diff changeset
405
17658
d6498b1ef50d Added section describing the iterator protocol.
Fred Drake <fdrake@acm.org>
parents: 17616
diff changeset
406
9083
bc41e86c938c Markup nits.
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parents: 9034
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407 \subsection{Sequence Types \label{typesseq}}
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408
13967
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach
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parents: 13933
diff changeset
409 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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diff changeset
410 tuples, buffers, and xrange objects.
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411
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412 String literals are written in single or double quotes:
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diff changeset
413 \code{'xyzzy'}, \code{"frobozz"}. See chapter 2 of the
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parents: 13894
diff changeset
414 \citetitle[../ref/strings.html]{Python Reference Manual} for more about
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parents: 13894
diff changeset
415 string literals. Unicode strings are much like strings, but are
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parents: 13894
diff changeset
416 specified in the syntax using a preceeding \character{u} character:
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417 \code{u'abc'}, \code{u"def"}. Lists are constructed with square brackets,
11463
17e12305973e Use \citetitle and \programopt as appropriate.
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418 separating items with commas: \code{[a, b, c]}. Tuples are
17e12305973e Use \citetitle and \programopt as appropriate.
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diff changeset
419 constructed by the comma operator (not within square brackets), with
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diff changeset
420 or without enclosing parentheses, but an empty tuple must have the
30375
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parents: 30250
diff changeset
421 enclosing parentheses, such as \code{a, b, c} or \code{()}. A single
4aa84a8b1fe4 Fix spacing markup and other sundries.
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422 item tuple must have a trailing comma, such as \code{(d,)}.
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423 \obindex{sequence}
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424 \obindex{string}
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425 \obindex{Unicode}
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426 \obindex{tuple}
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diff changeset
427 \obindex{list}
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1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
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diff changeset
428
1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
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diff changeset
429 Buffer objects are not directly supported by Python syntax, but can be
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430 created by calling the builtin function
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431 \function{buffer()}.\bifuncindex{buffer} They don't support
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diff changeset
432 concatenation or repetition.
18395
1d0d3e6a3201 List constraints on xrange() objects.
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433 \obindex{buffer}
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Guido van Rossum <guido@python.org>
parents: 18391
diff changeset
434
1d0d3e6a3201 List constraints on xrange() objects.
Guido van Rossum <guido@python.org>
parents: 18391
diff changeset
435 Xrange objects are similar to buffers in that there is no specific
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parents: 23847
diff changeset
436 syntax to create them, but they are created using the \function{xrange()}
63ee31bb25f3 Make a start at describing the results of class/type unification
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diff changeset
437 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
438 concatenation or repetition, and using \code{in}, \code{not in},
63ee31bb25f3 Make a start at describing the results of class/type unification
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diff changeset
439 \function{min()} or \function{max()} on them is inefficient.
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440 \obindex{xrange}
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441
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diff changeset
442 Most sequence types support the following operations. The \samp{in} and
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443 \samp{not in} operations have the same priorities as the comparison
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444 operations. The \samp{+} and \samp{*} operations have the same
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diff changeset
445 priority as the corresponding numeric operations.\footnote{They must
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diff changeset
446 have since the parser can't tell the type of the operands.}
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447
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448 This table lists the sequence operations sorted in ascending priority
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449 (operations in the same box have the same priority). In the table,
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diff changeset
450 \var{s} and \var{t} are sequences of the same type; \var{n}, \var{i}
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diff changeset
451 and \var{j} are integers:
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452
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453 \begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
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454 \lineiii{\var{x} in \var{s}}{\code{1} if an item of \var{s} is equal to \var{x}, else \code{0}}{(1)}
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455 \lineiii{\var{x} not in \var{s}}{\code{0} if an item of \var{s} is
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diff changeset
456 equal to \var{x}, else \code{1}}{(1)}
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457 \hline
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Raymond Hettinger <python@rcn.com>
parents: 32951
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458 \lineiii{\var{s} + \var{t}}{the concatenation of \var{s} and \var{t}}{(6)}
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parents: 24459
diff changeset
459 \lineiii{\var{s} * \var{n}\textrm{,} \var{n} * \var{s}}{\var{n} shallow copies of \var{s} concatenated}{(2)}
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460 \hline
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diff changeset
461 \lineiii{\var{s}[\var{i}]}{\var{i}'th item of \var{s}, origin 0}{(3)}
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462 \lineiii{\var{s}[\var{i}:\var{j}]}{slice of \var{s} from \var{i} to \var{j}}{(3), (4)}
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parents: 27919
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463 \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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464 \hline
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465 \lineiii{len(\var{s})}{length of \var{s}}{}
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466 \lineiii{min(\var{s})}{smallest item of \var{s}}{}
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467 \lineiii{max(\var{s})}{largest item of \var{s}}{}
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468 \end{tableiii}
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469 \indexiii{operations on}{sequence}{types}
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diff changeset
470 \bifuncindex{len}
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diff changeset
471 \bifuncindex{min}
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diff changeset
472 \bifuncindex{max}
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473 \indexii{concatenation}{operation}
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474 \indexii{repetition}{operation}
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diff changeset
475 \indexii{subscript}{operation}
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476 \indexii{slice}{operation}
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477 \indexii{extended slice}{operation}
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diff changeset
478 \opindex{in}
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diff changeset
479 \opindex{not in}
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480
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diff changeset
481 \noindent
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482 Notes:
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483
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diff changeset
484 \begin{description}
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diff changeset
485 \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
486 \code{in} and \code{not in} operations act like a substring test. In
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diff changeset
487 Python versions before 2.3, \var{x} had to be a string of length 1.
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parents: 24459
diff changeset
488 In Python 2.3 and beyond, \var{x} may be a string of any length.
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parents: 24459
diff changeset
489
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parents: 24459
diff changeset
490 \item[(2)] Values of \var{n} less than \code{0} are treated as
12223
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parents: 11463
diff changeset
491 \code{0} (which yields an empty sequence of the same type as
19529
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diff changeset
492 \var{s}). Note also that the copies are shallow; nested structures
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parents: 19243
diff changeset
493 are not copied. This often haunts new Python programmers; consider:
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
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parents: 19243
diff changeset
494
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
495 \begin{verbatim}
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
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diff changeset
496 >>> lists = [[]] * 3
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parents: 19243
diff changeset
497 >>> lists
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diff changeset
498 [[], [], []]
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parents: 19243
diff changeset
499 >>> lists[0].append(3)
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parents: 19243
diff changeset
500 >>> lists
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parents: 19243
diff changeset
501 [[3], [3], [3]]
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parents: 19243
diff changeset
502 \end{verbatim}
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parents: 19243
diff changeset
503
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
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parents: 19243
diff changeset
504 What has happened is that \code{lists} is a list containing three
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parents: 19243
diff changeset
505 copies of the list \code{[[]]} (a one-element list containing an
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parents: 19243
diff changeset
506 empty list), but the contained list is shared by each copy. You can
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diff changeset
507 create a list of different lists this way:
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Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
508
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so
Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
509 \begin{verbatim}
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Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
510 >>> lists = [[] for i in range(3)]
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diff changeset
511 >>> lists[0].append(3)
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diff changeset
512 >>> lists[1].append(5)
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parents: 19243
diff changeset
513 >>> lists[2].append(7)
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parents: 19243
diff changeset
514 >>> lists
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Fred Drake <fdrake@acm.org>
parents: 19243
diff changeset
515 [[3], [5], [7]]
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diff changeset
516 \end{verbatim}
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diff changeset
517
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diff changeset
518 \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
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parents: 18395
diff changeset
519 the end of the string: \code{len(\var{s}) + \var{i}} or
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520 \code{len(\var{s}) + \var{j}} is substituted. But note that \code{-0} is
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diff changeset
521 still \code{0}.
22241
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Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
522
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diff changeset
523 \item[(4)] The slice of \var{s} from \var{i} to \var{j} is defined as
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524 the sequence of items with index \var{k} such that \code{\var{i} <=
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diff changeset
525 \var{k} < \var{j}}. If \var{i} or \var{j} is greater than
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diff changeset
526 \code{len(\var{s})}, use \code{len(\var{s})}. If \var{i} is omitted,
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diff changeset
527 use \code{0}. If \var{j} is omitted, use \code{len(\var{s})}. If
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diff changeset
528 \var{i} is greater than or equal to \var{j}, the slice is empty.
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diff changeset
529
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Michael W. Hudson <mwh@python.net>
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diff changeset
530 \item[(5)] The slice of \var{s} from \var{i} to \var{j} with step
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
531 \var{k} is defined as the sequence of items with index
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
532 \code{\var{x} = \var{i} + \var{n}*\var{k}} such that \code{0}
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
533 \code{<=} \var{n} \code{<} \code{abs(i-j)}. If \var{i} or \var{j}
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
534 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
535 \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
536 (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
537 be zero.
28171
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Michael W. Hudson <mwh@python.net>
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diff changeset
538
32974
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
539 \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
540 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
541 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
542 \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
543 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
544 and implementation dependent. For performance sensitive code, it is
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
545 preferrable to use the \method{str.join()} method which assures consistent
fb6ffd290cfb SF patch #980695: efficient string concatenation
Raymond Hettinger <python@rcn.com>
parents: 32951
diff changeset
546 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
547 \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
548
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
549 \end{description}
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
550
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
551
13933
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parents: 13894
diff changeset
552 \subsubsection{String Methods \label{string-methods}}
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parents: 13894
diff changeset
553
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
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parents: 13894
diff changeset
554 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
555 objects support:
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
556
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
557 \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
558 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
559
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
560 For 8-bit strings, this method is locale-dependent.
13933
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parents: 13894
diff changeset
561 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
562
31021
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
563 \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
564 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
565 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
566 \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
567 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
568
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
569 \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
570 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
571 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
572 \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
573 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
574
21332
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
575 \begin{methoddesc}[string]{decode}{\optional{encoding\optional{, errors}}}
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
576 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
577 \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
578 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
579 \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
580 \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
581 \code{'replace'} and any other name registered via
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
582 \function{codecs.register_error}.
21332
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
583 \versionadded{2.2}
32459
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
584 \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
585 \end{methoddesc}
fbbd8a4ca7a6 Added documentation for str.decode().
Fred Drake <fdrake@acm.org>
parents: 21177
diff changeset
586
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
587 \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
588 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
589 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
590 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
591 \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
592 \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
593 \code{'replace'}, \code{'xmlcharrefreplace'}, \code{'backslashreplace'}
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
594 and any other name registered via \function{codecs.register_error}.
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
595 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
596 \versionadded{2.0}
32459
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
597 \versionchanged[Support for \code{'xmlcharrefreplace'} and
6b1ea5c07ff7 Document that encode() and decode() raise UnicodeError
Walter Dörwald <walter@livinglogic.de>
parents: 32458
diff changeset
598 \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
599 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
600
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
601 \begin{methoddesc}[string]{endswith}{suffix\optional{, start\optional{, end}}}
28171
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
602 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
603 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
604 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
605 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
606
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
607 \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
608 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
609 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
610 characters is assumed.
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]{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
614 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
615 found, such that \var{sub} is contained in the range [\var{start},
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
616 \var{end}). Optional arguments \var{start} and \var{end} are
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
617 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
618 not found.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
619 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
620
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
621 \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
622 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
623 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
624 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
625
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
626 \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
627 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
628 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
629
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
630 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
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]{isalpha}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
634 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
635 is at least one character, false otherwise.
32214
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Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
636
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
637 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
638 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
639
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
640 \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
641 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
642 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
643
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
644 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
645 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
646
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
647 \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
648 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
649 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
650
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
651 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
652 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
653
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
654 \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
655 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
656 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
657
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
658 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
659 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
660
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
661 \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
662 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
663 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
664 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
665 otherwise.
32214
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
666
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
667 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
668 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
669
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
670 \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
671 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
672 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
673
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
674 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
675 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
676
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
677 \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
678 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
679 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
680 providing this method.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
681 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
682
31021
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
683 \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
684 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
685 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
686 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
687 \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
688 \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
689 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
690
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
691 \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
692 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
693
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
694 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
695 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
696
23017
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
697 \begin{methoddesc}[string]{lstrip}{\optional{chars}}
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
698 Return a copy of the string with leading characters removed. If
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
699 \var{chars} is omitted or \code{None}, whitespace characters are
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
700 removed. If given and not \code{None}, \var{chars} must be a string;
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
701 the characters in the string will be stripped from the beginning of
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
702 the string this method is called on.
26259
60d809a25bae Document that a minor feature was added in 2.2.2. ;-(
Fred Drake <fdrake@acm.org>
parents: 26161
diff changeset
703 \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
704 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
705
30750
1d92ecdf2bb1 Avoid confusing name for the 3rd argument to str.replace().
Fred Drake <fdrake@acm.org>
parents: 30737
diff changeset
706 \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
707 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
708 \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
709 \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
710 replaced.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
711 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
712
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
713 \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
714 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
715 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
716 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
717 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
718 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
719
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
720 \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
721 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
722 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
723 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
724
31021
21a10c3600b5 Add optional fillchar argument to ljust(), rjust(), and center() string methods.
Raymond Hettinger <python@rcn.com>
parents: 31008
diff changeset
725 \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
726 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
727 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
728 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
729 \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
730 \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
731 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
732
31206
3771ff99d5f2 Update documentations for str.rsplit() with Alex Martelli's rewrite.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31199
diff changeset
733 \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
734 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
735 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
736 splits are done, the \emph{rightmost} ones. If \var{sep} is not specified
31206
3771ff99d5f2 Update documentations for str.rsplit() with Alex Martelli's rewrite.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31199
diff changeset
737 or \code{None}, any whitespace string is a separator.
31199
504943c89193 Add rsplit method for str and unicode builtin types.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31022
diff changeset
738 \versionadded{2.4}
504943c89193 Add rsplit method for str and unicode builtin types.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31022
diff changeset
739 \end{methoddesc}
504943c89193 Add rsplit method for str and unicode builtin types.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31022
diff changeset
740
23017
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
741 \begin{methoddesc}[string]{rstrip}{\optional{chars}}
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
742 Return a copy of the string with trailing characters removed. If
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
743 \var{chars} is omitted or \code{None}, whitespace characters are
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
744 removed. If given and not \code{None}, \var{chars} must be a string;
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
745 the characters in the string will be stripped from the end of the
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
746 string this method is called on.
26259
60d809a25bae Document that a minor feature was added in 2.2.2. ;-(
Fred Drake <fdrake@acm.org>
parents: 26161
diff changeset
747 \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
748 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
749
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
750 \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
751 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
752 delimiter string. If \var{maxsplit} is given, at most \var{maxsplit}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
753 splits are done. If \var{sep} is not specified or \code{None}, any
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
754 whitespace string is a separator.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
755 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
756
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
757 \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
758 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
759 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
760 \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
761 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
762
23017
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
763 \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
764 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
765 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
766 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
767 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
768 position.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
769 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
770
23017
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
771 \begin{methoddesc}[string]{strip}{\optional{chars}}
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
772 Return a copy of the string with leading and trailing characters
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
773 removed. If \var{chars} is omitted or \code{None}, whitespace
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
774 characters are removed. If given and not \code{None}, \var{chars}
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
775 must be a string; the characters in the string will be stripped from
44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string
Fred Drake <fdrake@acm.org>
parents: 22994
diff changeset
776 the both ends of the string this method is called on.
26259
60d809a25bae Document that a minor feature was added in 2.2.2. ;-(
Fred Drake <fdrake@acm.org>
parents: 26161
diff changeset
777 \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
778 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
779
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
780 \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
781 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
782 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
783
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
784 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
785 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
786
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
787 \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
788 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
789 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
790
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
791 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
792 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
793
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
794 \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
795 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
796 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
797 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
798 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
799
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate()
Raymond Hettinger <python@rcn.com>
parents: 29590
diff changeset
800 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
801 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
802 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
803 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
804 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
805 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
806 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
807 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
808 \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
809 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
810
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
811 \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
812 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
813
6478eb6ae3c0 Document string methods that are locale-dependent. Fixes #935749.
Martin v. Löwis <martin@v.loewis.de>
parents: 32197
diff changeset
814 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
815 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
816
23045
8b1268bc371a Apply the second version of SF patch http://www.python.org/sf/536241
Walter Dörwald <walter@livinglogic.de>
parents: 23017
diff changeset
817 \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
818 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
819 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
820 \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
821 \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
822 \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
823
13933
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
824
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some
Fred Drake <fdrake@acm.org>
parents: 13894
diff changeset
825 \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
826
21177
7d1eac41ce3e Slightly improved indexing for the string-% operator, thanks to comments
Fred Drake <fdrake@acm.org>
parents: 21163
diff changeset
827 \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
828 \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
829 \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
830 \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
831 \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
832 \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
833 \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
834 \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
835
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
836 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
837 \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
838 \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
839 \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
840 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
841 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
842 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
843 \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
844 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
845 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
846
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
847 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
848 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
849 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
850 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
851 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
852 single mapping object (for example, a dictionary).
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
853
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
854 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
855 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
856
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
857 \begin{enumerate}
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
858 \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
859 specifier.
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
860 \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
861 of characters (for example, \code{(somename)}).
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
862 \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
863 conversion types.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
864 \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
865 \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
866 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
867 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
868 precision.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
869 \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
870 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
871 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
872 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
873 the precision.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
874 \item Length modifier (optional).
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
875 \item Conversion type.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
876 \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
877
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
878 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
879 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
880 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
881 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
882 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
883
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
884 \begin{verbatim}
23860
63ee31bb25f3 Make a start at describing the results of class/type unification
Steve Holden <steve@holdenweb.com>
parents: 23847
diff changeset
885 >>> 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
886 {'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
887 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
888 \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
889
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
890 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
891 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
892
16285
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
893 The conversion flag characters are:
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 \begin{tableii}{c|l}{character}{Flag}{Meaning}
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
896 \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
897 (where defined below).}
27919
4b5c2e025c5e Fix SF bug #687655, String formatting conversions misleading
Neal Norwitz <nnorwitz@gmail.com>
parents: 27225
diff changeset
898 \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
899 \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
900 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
901 \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
902 (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
903 \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
904 precede the conversion (overrides a "space" flag).}
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
905 \end{tableii}
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
906
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
907 The length modifier may be \code{h}, \code{l}, and \code{L} may be
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
908 present, but are ignored as they are not necessary for Python.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
909
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
910 The conversion types are:
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
911
25906
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
912 \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
913 \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
914 \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
915 \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
916 \lineiii{u}{Unsigned decimal.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
917 \lineiii{x}{Unsigned hexidecimal (lowercase).}{(2)}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
918 \lineiii{X}{Unsigned hexidecimal (uppercase).}{(2)}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
919 \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
920 \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
921 \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
922 \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
923 \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
924 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
925 \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
926 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
927 \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
928 string).}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
929 \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
930 \function{repr()}).}{(3)}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
931 \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
932 \function{str()}).}{(4)}
25906
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
933 \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
934 character in the result.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
935 \end{tableiii}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
936
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
937 \noindent
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
938 Notes:
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
939 \begin{description}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
940 \item[(1)]
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
941 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
942 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
943 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
944 zero.
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
945 \item[(2)]
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
946 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
947 (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
948 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
949 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
950 not already a zero.
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
951 \item[(3)]
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag.
Fred Drake <fdrake@acm.org>
parents: 25393
diff changeset
952 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
953 \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
954 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
955 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
956 \end{description}
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 % XXX Examples?
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
959
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
960 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
961 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
962
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
963 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
964 \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
965 are replaced by \code{\%g} conversions.\footnote{
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
966 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
967 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
968 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
969 point values on a particular machine.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
970 } All other errors raise exceptions.
15e0c10092bb Massively improved documentation for string formatting operations,
Fred Drake <fdrake@acm.org>
parents: 15926
diff changeset
971
21163
7b6879714b74 Make no assumption about how modules are built when referring to them; this
Fred Drake <fdrake@acm.org>
parents: 21159
diff changeset
972 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
973 \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
974 \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
975
13967
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach
Fred Drake <fdrake@acm.org>
parents: 13933
diff changeset
976
14044
a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange()
Fred Drake <fdrake@acm.org>
parents: 13967
diff changeset
977 \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
978
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
979 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
980 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
981 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
982 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
983 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
984
26592
0c646baeec58 Update comments about the performance of xrange().
Raymond Hettinger <python@rcn.com>
parents: 26514
diff changeset
985 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
986 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
987
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach
Fred Drake <fdrake@acm.org>
parents: 13933
diff changeset
988
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
989 \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
990
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
991 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
992 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
993 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
994 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
995 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
996 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
997 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
998 \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
999 \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
1000 \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
1001
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1002 \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
1003 \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
1004 {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
1005 \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
1006 {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
1007 \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
1008 {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
1009 \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
1010 {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
1011 \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
1012 {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
1013 \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
1014 {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
1015 \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
1016 {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
1017 \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
1018 {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
1019 \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
1020 {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
1021 \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
1022 \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
1023 {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
1024 \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
1025 {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
1026 \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
1027 {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
1028 \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
1029 {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
1030 \lineiii{\var{s}.sort(\optional{\var{cmp}\optional{,
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1031 \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
1032 {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
1033 \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
1034 \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
1035 \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
1036 \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
1037 \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
1038 \indexii{slice}{assignment}
28171
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1039 \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
1040 \stindex{del}
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1041 \withsubitem{(list method)}{
11183
1e0b1967be7f In note mentioning [].remove()'s exception, tell what exception is
Fred Drake <fdrake@acm.org>
parents: 11100
diff changeset
1042 \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
1043 \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
1044 \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
1045 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1046 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1047 \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
1048 \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
1049 replacing.
23778
245224d1b8c9 This is my nearly two year old patch
Michael W. Hudson <mwh@python.net>
parents: 23515
diff changeset
1050
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1051 \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
1052 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
1053 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
1054 deprecated since Python 1.4.
12223
e82e82b3b9ad Merged changes from the 1.5.2p2 release.
Fred Drake <fdrake@acm.org>
parents: 11463
diff changeset
1055
31357
c088584f5533 SF bug #872461: list.extend() described as experimental
Raymond Hettinger <python@rcn.com>
parents: 31298
diff changeset
1056 \item[(3)] Raises an exception when \var{x} is not a list object.
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1057
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1058 \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
1059 \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
1060 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
1061 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
1062 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
1063 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
1064
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1065 \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
1066 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
1067 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
1068 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
1069 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
1070
28171
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1071 \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
1072 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
1073 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
1074
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1075 \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
1076 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
1077 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
1078 the sorted or reversed list.
12223
e82e82b3b9ad Merged changes from the 1.5.2p2 release.
Fred Drake <fdrake@acm.org>
parents: 11463
diff changeset
1079
31210
c06b570adf12 Guido grants a Christmas wish:
Raymond Hettinger <python@rcn.com>
parents: 31206
diff changeset
1080 \item[(8)] The \method{sort()} method takes optional arguments for
c06b570adf12 Guido grants a Christmas wish:
Raymond Hettinger <python@rcn.com>
parents: 31206
diff changeset
1081 controlling the comparisions.
30697
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1082
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1083 \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
1084 (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
1085 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
1086 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
1087 \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
1088 \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
1089
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1090 \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
1091 extract a comparison key from each list element:
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1092 \samp{\var{cmp}=\function{str.lower}}
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1093
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1094 \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
1095 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
1096
1345c23a0591 * list.sort() now supports three keyword arguments: cmp, key, and reverse.
Raymond Hettinger <python@rcn.com>
parents: 30413
diff changeset
1097 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
1098 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
1099 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
1100 \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
1101
28337
90f17c374f59 - added example of using a comparison function with list.sort(), and
Fred Drake <fdrake@acm.org>
parents: 28211
diff changeset
1102 \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
1103 \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
1104
30737
38b0b7d41936 markup fixes; this would not format
Fred Drake <fdrake@acm.org>
parents: 30707
diff changeset
1105 \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
1106
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1107 \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
1108 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
1109 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
1110 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
1111 department, then by salary grade).
26161
dd10d97d329a SF patch 637176: list.sort crasher
Tim Peters <tim.peters@gmail.com>
parents: 25906
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[(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
1114 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
1115 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
1116 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
1117 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
1118 \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
1119
31008
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parents: 30813
diff changeset
1120 \subsection{Set Types \label{types-set}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1121 \obindex{set}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1122
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1123 A \dfn{set} object is an unordered collection of immutable values.
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1124 Common uses include membership testing, removing duplicates from a sequence,
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1125 and computing mathematical operations such as intersection, union, difference,
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1126 and symmetric difference.
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1127 \versionadded{2.4}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1128
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1129 Like other collections, sets support \code{\var{x} in \var{set}},
4224d807911c * Checkin remaining documentation
Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1130 \code{len(\var{set})}, and \code{for \var{x} in \var{set}}. Being an
4224d807911c * Checkin remaining documentation
Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1131 unordered collection, sets do not record element position or order of
4224d807911c * Checkin remaining documentation
Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1132 insertion. Accordingly, sets do not support indexing, slicing, or
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1133 other sequence-like behavior.
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1134
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1135 There are currently two builtin set types, \class{set} and \class{frozenset}.
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1136 The \class{set} type is mutable --- the contents can be changed using methods
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1137 like \method{add()} and \method{remove()}. Since it is mutable, it has no
4224d807911c * Checkin remaining documentation
Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1138 hash value and cannot be used as either a dictionary key or as an element of
4224d807911c * Checkin remaining documentation
Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1139 another set. The \class{frozenset} type is immutable and hashable --- its
4224d807911c * Checkin remaining documentation
Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1140 contents cannot be altered after is created; however, it can be used as
4224d807911c * Checkin remaining documentation
Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1141 a dictionary key or as an element of another set.
4224d807911c * Checkin remaining documentation
Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1142
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1143 Instances of \class{set} and \class{frozenset} provide the following operations:
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1144
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1145 \begin{tableiii}{c|c|l}{code}{Operation}{Equivalent}{Result}
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parents: 30813
diff changeset
1146 \lineiii{len(\var{s})}{}{cardinality of set \var{s}}
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parents: 30813
diff changeset
1147
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1148 \hline
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parents: 30813
diff changeset
1149 \lineiii{\var{x} in \var{s}}{}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1150 {test \var{x} for membership in \var{s}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1151 \lineiii{\var{x} not in \var{s}}{}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1152 {test \var{x} for non-membership in \var{s}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1153 \lineiii{\var{s}.issubset(\var{t})}{\code{\var{s} <= \var{t}}}
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parents: 30813
diff changeset
1154 {test whether every element in \var{s} is in \var{t}}
4224d807911c * Checkin remaining documentation
Raymond Hettinger <python@rcn.com>
parents: 30813
diff changeset
1155 \lineiii{\var{s}.issuperset(\var{t})}{\code{\var{s} >= \var{t}}}
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parents: 30813
diff changeset
1156 {test whether every element in \var{t} is in \var{s}}
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parents: 30813
diff changeset
1157
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1158 \hline
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parents: 30813
diff changeset
1159 \lineiii{\var{s}.union(\var{t})}{\var{s} | \var{t}}
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parents: 30813
diff changeset
1160 {new set with elements from both \var{s} and \var{t}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1161 \lineiii{\var{s}.intersection(\var{t})}{\var{s} \&\ \var{t}}
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parents: 30813
diff changeset
1162 {new set with elements common to \var{s} and \var{t}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1163 \lineiii{\var{s}.difference(\var{t})}{\var{s} - \var{t}}
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parents: 30813
diff changeset
1164 {new set with elements in \var{s} but not in \var{t}}
4224d807911c * Checkin remaining documentation
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parents: 30813
diff changeset
1165 \lineiii{\var{s}.symmetric_difference(\var{t})}{\var{s} \^\ \var{t}}
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parents: 30813
diff changeset
1166 {new set with elements in either \var{s} or \var{t} but not both}
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parents: 30813
diff changeset
1167 \lineiii{\var{s}.copy()}{}
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parents: 30813
diff changeset
1168 {new set with a shallow copy of \var{s}}
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parents: 30813
diff changeset
1169 \end{tableiii}
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parents: 30813
diff changeset
1170
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parents: 30813
diff changeset
1171 Note, the non-operator versions of \method{union()}, \method{intersection()},
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diff changeset
1172 \method{difference()}, and \method{symmetric_difference()},
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diff changeset
1173 \method{issubset()}, and \method{issuperset()} methods will accept any
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diff changeset
1174 iterable as an argument. In contrast, their operator based counterparts
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diff changeset
1175 require their arguments to be sets. This precludes error-prone constructions
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diff changeset
1176 like \code{set('abc') \&\ 'cbs'} in favor of the more readable
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diff changeset
1177 \code{set('abc').intersection('cbs')}.
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diff changeset
1178
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diff changeset
1179 Both \class{set} and \class{frozenset} support set to set comparisons.
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diff changeset
1180 Two sets are equal if and only if every element of each set is contained in
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diff changeset
1181 the other (each is a subset of the other).
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diff changeset
1182 A set is less than another set if and only if the first set is a proper
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diff changeset
1183 subset of the second set (is a subset, but is not equal).
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diff changeset
1184 A set is greater than another set if and only if the first set is a proper
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diff changeset
1185 superset of the second set (is a superset, but is not equal).
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diff changeset
1186
32795
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
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diff changeset
1187 Instanceas of \class{set} are compared to instances of \class{frozenset} based
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
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parents: 32459
diff changeset
1188 on their members. For example, \samp{set('abc') == frozenset('abc')} returns
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
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parents: 32459
diff changeset
1189 \code{True}.
46e0431c9701 SF bug #995983 and #995987: Documentation nits.
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parents: 32459
diff changeset
1190
31008
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diff changeset
1191 The subset and equality comparisons do not generalize to a complete
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diff changeset
1192 ordering function. For example, any two disjoint sets are not equal and
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diff changeset
1193 are not subsets of each other, so \emph{all} of the following return
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diff changeset
1194 \code{False}: \code{\var{a}<\var{b}}, \code{\var{a}==\var{b}}, or
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diff changeset
1195 \code{\var{a}>\var{b}}.
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diff changeset
1196 Accordingly, sets do not implement the \method{__cmp__} method.
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diff changeset
1197
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diff changeset
1198 Since sets only define partial ordering (subset relationships), the output
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diff changeset
1199 of the \method{list.sort()} method is undefined for lists of sets.
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diff changeset
1200
32795
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diff changeset
1201 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
1202 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
1203 \samp{frozenset('ab') | set('bc')} returns an instance of \class{frozenset}.
31008
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diff changeset
1204
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diff changeset
1205 The following table lists operations available for \class{set}
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diff changeset
1206 that do not apply to immutable instances of \class{frozenset}:
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diff changeset
1207
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diff changeset
1208 \begin{tableiii}{c|c|l}{code}{Operation}{Equivalent}{Result}
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1209 \lineiii{\var{s}.update(\var{t})}
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diff changeset
1210 {\var{s} |= \var{t}}
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diff changeset
1211 {return set \var{s} with elements added from \var{t}}
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diff changeset
1212 \lineiii{\var{s}.intersection_update(\var{t})}
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diff changeset
1213 {\var{s} \&= \var{t}}
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diff changeset
1214 {return set \var{s} keeping only elements also found in \var{t}}
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diff changeset
1215 \lineiii{\var{s}.difference_update(\var{t})}
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diff changeset
1216 {\var{s} -= \var{t}}
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diff changeset
1217 {return set \var{s} after removing elements found in \var{t}}
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diff changeset
1218 \lineiii{\var{s}.symmetric_difference_update(\var{t})}
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diff changeset
1219 {\var{s} \textasciicircum= \var{t}}
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diff changeset
1220 {return set \var{s} with elements from \var{s} or \var{t}
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1221 but not both}
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diff changeset
1222
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diff changeset
1223 \hline
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1224 \lineiii{\var{s}.add(\var{x})}{}
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diff changeset
1225 {add element \var{x} to set \var{s}}
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diff changeset
1226 \lineiii{\var{s}.remove(\var{x})}{}
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diff changeset
1227 {remove \var{x} from set \var{s}; raises KeyError if not present}
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diff changeset
1228 \lineiii{\var{s}.discard(\var{x})}{}
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diff changeset
1229 {removes \var{x} from set \var{s} if present}
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diff changeset
1230 \lineiii{\var{s}.pop()}{}
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diff changeset
1231 {remove and return an arbitrary element from \var{s}; raises
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diff changeset
1232 \exception{KeyError} if empty}
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1233 \lineiii{\var{s}.clear()}{}
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diff changeset
1234 {remove all elements from set \var{s}}
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diff changeset
1235 \end{tableiii}
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1236
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diff changeset
1237 Note, the non-operator versions of the \method{update()},
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diff changeset
1238 \method{intersection_update()}, \method{difference_update()}, and
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diff changeset
1239 \method{symmetric_difference_update()} methods will accept any iterable
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1240 as an argument.
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1241
8730
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diff changeset
1242
9083
bc41e86c938c Markup nits.
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parents: 9034
diff changeset
1243 \subsection{Mapping Types \label{typesmapping}}
15005
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is
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diff changeset
1244 \obindex{mapping}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is
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diff changeset
1245 \obindex{dictionary}
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diff changeset
1246
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diff changeset
1247 A \dfn{mapping} object maps immutable values to
8730
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diff changeset
1248 arbitrary objects. Mappings are mutable objects. There is currently
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
1249 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
1250 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
1251 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
1252 object identity) may not be used as keys.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
1253 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
1254 comparison: if two numbers compare equal (such as \code{1} and
8730
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parents:
diff changeset
1255 \code{1.0}) then they can be used interchangeably to index the same
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diff changeset
1256 dictionary entry.
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parents:
diff changeset
1257
8a306dfd9f33 Move files around to get the names to match the module names except for
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diff changeset
1258 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
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parents:
diff changeset
1259 \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
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parents:
diff changeset
1260 \code{\{'jack': 4098, 'sjoerd': 4127\}} or
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
1261 \code{\{4098: 'jack', 4127: 'sjoerd'\}}.
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parents:
diff changeset
1262
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diff changeset
1263 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
1264 \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
1265 arbitrary objects):
8730
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parents:
diff changeset
1266 \indexiii{operations on}{mapping}{types}
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
1267 \indexiii{operations on}{dictionary}{type}
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
1268 \stindex{del}
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
1269 \bifuncindex{len}
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
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parents: 10147
diff changeset
1270 \withsubitem{(dictionary method)}{
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
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parents: 10147
diff changeset
1271 \ttindex{clear()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
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parents: 10147
diff changeset
1272 \ttindex{copy()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1273 \ttindex{has_key()}
30413
53f1c32ee69d SF bug #804280: fromkeys is not listed in index
Raymond Hettinger <python@rcn.com>
parents: 30375
diff changeset
1274 \ttindex{fromkeys()}
10156
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Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1275 \ttindex{items()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
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parents: 10147
diff changeset
1276 \ttindex{keys()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
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parents: 10147
diff changeset
1277 \ttindex{update()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1278 \ttindex{values()}
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1279 \ttindex{get()}
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parents: 27919
diff changeset
1280 \ttindex{setdefault()}
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1281 \ttindex{pop()}
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1282 \ttindex{popitem()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1283 \ttindex{iteritems()}
29067
04065c4a1c6b Missing parenthesis found by texcheck.py
Raymond Hettinger <python@rcn.com>
parents: 29065
diff changeset
1284 \ttindex{iterkeys()}
28171
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Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1285 \ttindex{itervalues()}}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
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parents: 10785
diff changeset
1286
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
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parents: 10785
diff changeset
1287 \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
1288 \lineiii{len(\var{a})}{the number of items in \var{a}}{}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
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parents: 10785
diff changeset
1289 \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
1290 \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
1291 {set \code{\var{a}[\var{k}]} to \var{v}}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
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parents: 10785
diff changeset
1292 {}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
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parents: 10785
diff changeset
1293 \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
1294 {remove \code{\var{a}[\var{k}]} from \var{a}}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
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parents: 10785
diff changeset
1295 {(1)}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
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parents: 10785
diff changeset
1296 \lineiii{\var{a}.clear()}{remove all items from \code{a}}{}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
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parents: 10785
diff changeset
1297 \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
1298 \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
1299 {\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
1300 {}
17616
7acba78e1e09 At the suggestion of Peter Funk, document 'key in dict' and 'key not
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parents: 17612
diff changeset
1301 \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
1302 {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
1303 {(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
1304 \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
1305 {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
1306 {(2)}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1307 \lineiii{\var{a}.items()}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1308 {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
1309 {(3)}
18085
7e459fb3c332 Fixed reference to table notes for {}.keys() and {}.items() -- these
Fred Drake <fdrake@acm.org>
parents: 17966
diff changeset
1310 \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
1311 \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
1312 {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
1313 {(9)}
26437
57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class
Raymond Hettinger <python@rcn.com>
parents: 26260
diff changeset
1314 \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
1315 {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
1316 {(7)}
18085
7e459fb3c332 Fixed reference to table notes for {}.keys() and {}.items() -- these
Fred Drake <fdrake@acm.org>
parents: 17966
diff changeset
1317 \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
1318 \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
1319 {\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
1320 else \var{x}}
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1321 {(4)}
13894
77b9e041b595 Barry's patch to document the new setdefault() method. Slightly
Guido van Rossum <guido@python.org>
parents: 13780
diff changeset
1322 \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
1323 {\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
1324 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
1325 {(5)}
28211
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop
Raymond Hettinger <python@rcn.com>
parents: 28171
diff changeset
1326 \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
1327 {\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
1328 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
1329 {(8)}
15522
aaa54752e4ba "Documentation" for {}.popitem().
Guido van Rossum <guido@python.org>
parents: 15463
diff changeset
1330 \lineiii{\var{a}.popitem()}
aaa54752e4ba "Documentation" for {}.popitem().
Guido van Rossum <guido@python.org>
parents: 15463
diff changeset
1331 {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
1332 {(6)}
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1333 \lineiii{\var{a}.iteritems()}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1334 {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
1335 {(2), (3)}
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1336 \lineiii{\var{a}.iterkeys()}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1337 {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
1338 {(2), (3)}
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1339 \lineiii{\var{a}.itervalues()}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1340 {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
1341 {(2), (3)}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1342 \end{tableiii}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1343
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1344 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1345 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1346 \begin{description}
10968
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments
Fred Drake <fdrake@acm.org>
parents: 10785
diff changeset
1347 \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
1348 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
1349
17966
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1350 \item[(2)] \versionadded{2.2}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1351
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues()
Fred Drake <fdrake@acm.org>
parents: 17663
diff changeset
1352 \item[(3)] Keys and values are listed in random order. If
24902
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1353 \method{items()}, \method{keys()}, \method{values()},
f57d6db423f2 Extend some comments on the order of values in the returns from
Fred Drake <fdrake@acm.org>
parents: 24631
diff changeset
1354 \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
1355 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
1356 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
1357 \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
1358 \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
1359 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
1360 \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
1361 \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
1362 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
1363 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
1364
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1365 \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
1366 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
1367 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
1368
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1369 \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
1370 that if \var{k} is missing, \var{x} is both returned and inserted into
77b9e041b595 Barry's patch to document the new setdefault() method. Slightly
Guido van Rossum <guido@python.org>
parents: 13780
diff changeset
1371 the dictionary as the value of \var{k}.
15522
aaa54752e4ba "Documentation" for {}.popitem().
Guido van Rossum <guido@python.org>
parents: 15463
diff changeset
1372
18286
bc05a95242a3 Remove the restriction on a mapping's .update() method.
Barry Warsaw <barry@python.org>
parents: 18085
diff changeset
1373 \item[(6)] \function{popitem()} is useful to destructively iterate
15522
aaa54752e4ba "Documentation" for {}.popitem().
Guido van Rossum <guido@python.org>
parents: 15463
diff changeset
1374 over a dictionary, as often used in set algorithms.
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1375
26437
57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class
Raymond Hettinger <python@rcn.com>
parents: 26260
diff changeset
1376 \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
1377 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
1378
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop
Raymond Hettinger <python@rcn.com>
parents: 28171
diff changeset
1379 \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
1380 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
1381
31616
5b3898d9ba59 SF #904720: dict.update should take a 2-tuple sequence like dict.__init_
Raymond Hettinger <python@rcn.com>
parents: 31357
diff changeset
1382 \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
1383 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
1384 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
1385 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
1386 \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
1387 \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
1388 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
1389
31631
228d264c5fbb SF Patch #912462: Relocate \end tag to the right place.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31616
diff changeset
1390 \end{description}
228d264c5fbb SF Patch #912462: Relocate \end tag to the right place.
Hye-Shik Chang <hyeshik@gmail.com>
parents: 31616
diff changeset
1391
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1392 \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
1393 \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
1394
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1395 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
1396 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
1397 \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
1398 \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
1399 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
1400 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
1401 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
1402 \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
1403 \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
1404 \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
1405 \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
1406
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1407 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
1408 \exception{IOError} is raised. This includes situations where the
fa867d8ee7eb Remove some remaining {\rm ...} constructs.
Fred Drake <fdrake@acm.org>
parents: 9523
diff changeset
1409 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
1410 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
1411
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1412 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
1413
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1414
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1415 \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
1416 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
1417 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
1418 \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
1419 \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
1420 \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
1421
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1422 \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
1423 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
1424 \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
1425 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
1426 \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
1427
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1428 \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
1429 \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
1430 \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
1431 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
1432 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
1433 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
1434 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
1435 \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
1436 \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
1437 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
1438 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
1439 \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
1440
24599
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1441 \begin{methoddesc}[file]{isatty}{}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1442 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
1443 \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
1444 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
1445 \end{methoddesc}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1446
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1447 \begin{methoddesc}[file]{next}{}
30413
53f1c32ee69d SF bug #804280: fromkeys is not listed in index
Raymond Hettinger <python@rcn.com>
parents: 30375
diff changeset
1448 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
1449 \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
1450 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
1451 \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
1452 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
1453 \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
1454 \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
1455 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
1456 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
1457 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
1458 \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
1459 \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
1460 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
1461 \versionadded{2.3}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1462 \end{methoddesc}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and
Guido van Rossum <guido@python.org>
parents: 24598
diff changeset
1463
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1464 \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
1465 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
1466 \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
1467 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
1468 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
1469 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
1470 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
1471 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
1472 C function \cfunction{fread()} more than once in an effort to
26672
8dd25a6f5913 Fixed bug
Gustavo Niemeyer <gustavo@niemeyer.net>
parents: 26592
diff changeset
1473 acquire as close to \var{size} bytes as possible. Also note that
8dd25a6f5913 Fixed bug
Gustavo Niemeyer <gustavo@niemeyer.net>
parents: 26592
diff changeset
1474 when in non-blocking mode, less data than what was requested may
8dd25a6f5913 Fixed bug
Gustavo Niemeyer <gustavo@niemeyer.net>
parents: 26592
diff changeset
1475 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
1476 \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
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 \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
1479 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
1480 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
1481 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
1482 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
1483 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
1484 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
1485 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
1486 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
1487 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
1488 or not (yes this happens!).
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1489 } 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
1490 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
1491 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
1492 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
1493 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
1494 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
1495 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
1496 \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
1497
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1498 \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
1499 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
1500 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
1501 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
1502 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
1503 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
1504 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
1505 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
1506 \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
1507
15926
ac13cef423c8 Document xreadlines() method. (Forgot to check this in before!)
Guido van Rossum <guido@python.org>
parents: 15896
diff changeset
1508 \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
1509 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
1510 \versionadded{2.1}
31286
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1511 \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
1512 \end{methoddesc}
ac13cef423c8 Document xreadlines() method. (Forgot to check this in before!)
Guido van Rossum <guido@python.org>
parents: 15896
diff changeset
1513
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1514 \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
1515 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
1516 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
1517 (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
1518 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
1519 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
1520 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
1521 \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
1522 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
1523 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
1524 opened in append mode with reading enabled (mode \code{'a+'}). If the
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
1525 file is opened in text mode (mode \code{'t'}), only offsets returned
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
1526 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
1527 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
1528
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
1529 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
1530 \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
1531
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1532 \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
1533 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
1534 \cfunction{ftell()}.
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1535 \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
1536
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1537 \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
1538 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
1539 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
1540 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
1541 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
1542 current size, the result is platform-dependent: possibilities
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1543 include that file may remain unchanged, increase to the specified
7584b6f1afde Change Windows file.truncate() to (a) restore the original file position,
Tim Peters <tim.peters@gmail.com>
parents: 22214
diff changeset
1544 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
1545 undefined new content.
30375
4aa84a8b1fe4 Fix spacing markup and other sundries.
Raymond Hettinger <python@rcn.com>
parents: 30250
diff changeset
1546 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
1547 \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
1548
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1549 \begin{methoddesc}[file]{write}{str}
20580
376ee174ecd0 Use the \note and \warning macros where appropriate.
Fred Drake <fdrake@acm.org>
parents: 20173
diff changeset
1550 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
1551 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
1552 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
1553 \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
1554
20045
7b8c11739714 Generalize file.writelines() to allow iterable objects.
Tim Peters <tim.peters@gmail.com>
parents: 20031
diff changeset
1555 \begin{methoddesc}[file]{writelines}{sequence}
7b8c11739714 Generalize file.writelines() to allow iterable objects.
Tim Peters <tim.peters@gmail.com>
parents: 20031
diff changeset
1556 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
1557 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
1558 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
1559 (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
1560 \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
1561 \end{methoddesc}
9e9556924b0a Added documentation for the xreadlines module & related changes. The
Fred Drake <fdrake@acm.org>
parents: 15731
diff changeset
1562
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1563
20031
e5a3f9d7766b Note that files are iterable; describe what the iterator returns.
Fred Drake <fdrake@acm.org>
parents: 19529
diff changeset
1564 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
1565 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
1566 \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
1567
e5a3f9d7766b Note that files are iterable; describe what the iterator returns.
Fred Drake <fdrake@acm.org>
parents: 19529
diff changeset
1568
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 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
1570 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
1571 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
1572
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1573 \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
1574 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
1575 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
1576 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
1577 \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
1578
29065
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1579 \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
1580 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
1581 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
1582 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
1583 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
1584 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
1585 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
1586 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
1587 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
1588 strings.
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1589
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1590 \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
1591 \end{memberdesc}
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine
Martin v. Löwis <martin@v.loewis.de>
parents: 28909
diff changeset
1592
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1593 \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
1594 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
1595 \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
1596 \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
1597 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
1598 \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
1599
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1600 \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
1601 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
1602 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
1603 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
1604 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
1605 \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
1606
28171
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1607 \begin{memberdesc}[file]{newlines}
31282
8b62f4194a7e markup fix
Fred Drake <fdrake@acm.org>
parents: 31210
diff changeset
1608 If Python was built with the \longprogramopt{with-universal-newlines}
8b62f4194a7e markup fix
Fred Drake <fdrake@acm.org>
parents: 31210
diff changeset
1609 option to \program{configure} (the default) this read-only attribute
8b62f4194a7e markup fix
Fred Drake <fdrake@acm.org>
parents: 31210
diff changeset
1610 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
1611 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
1612 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
1613 \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
1614 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
1615 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
1616 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
1617 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
1618 \end{memberdesc}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped
Michael W. Hudson <mwh@python.net>
parents: 27919
diff changeset
1619
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1620 \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
1621 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
1622 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
1623 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
1624 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
1625 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
1626 (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
1627 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
1628 \member{softspace} attribute.
20580
376ee174ecd0 Use the \note and \warning macros where appropriate.
Fred Drake <fdrake@acm.org>
parents: 20173
diff changeset
1629 \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
1630 \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
1631 \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
1632 \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
1633
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1634
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1635 \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
1636
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1637 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
1638 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
1639
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1640
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1641 \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
1642
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1643 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
1644 \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
1645 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
1646 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
1647 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
1648 \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
1649 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
1650 \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
1651
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1652 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
1653 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
1654 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
1655 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
1656 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
1657 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
1658 \code{\var{m}.__dict__ = \{\}}). Modifying \member{__dict__} directly
3894654b4848 fix a variety of markup bugs
Fred Drake <fdrake@acm.org>
parents: 31282
diff changeset
1659 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
1660
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1661 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
1662 \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
1663 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
1664 '/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
1665
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1666
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1667 \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
1668 \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
1669
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1670 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
1671 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
1672
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1673
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1674 \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
1675
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1676 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
1677 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
1678 \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
1679
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1680 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
1681 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
1682 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
1683 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
1684
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1685 The implementation adds two special read-only attributes:
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1686 \code{\var{f}.func_code} is a function's \dfn{code
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1687 object}\obindex{code} (see below) and \code{\var{f}.func_globals} is
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1688 the dictionary used as the function's global namespace (this is the
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1689 same as \code{\var{m}.__dict__} where \var{m} is the module in which
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1690 the function \var{f} was defined).
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1691
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1692 Function objects also support getting and setting arbitrary
30413
53f1c32ee69d SF bug #804280: fromkeys is not listed in index
Raymond Hettinger <python@rcn.com>
parents: 30375
diff changeset
1693 attributes, which can be used, for example, to attach metadata to
53f1c32ee69d SF bug #804280: fromkeys is not listed in index
Raymond Hettinger <python@rcn.com>
parents: 30375
diff changeset
1694 functions. Regular attribute dot-notation is used to get and set such
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1695 attributes. \emph{Note that the current implementation only supports
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1696 function attributes on user-defined functions. Function attributes on
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1697 built-in functions may be supported in the future.}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1698
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1699 Functions have another special attribute \code{\var{f}.__dict__}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1700 (a.k.a. \code{\var{f}.func_dict}) which contains the namespace used to
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1701 support function attributes. \code{__dict__} and \code{func_dict} can
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1702 be accessed directly or set to a dictionary object. A function's
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1703 dictionary cannot be deleted.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1704
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1705 \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
1706 \obindex{method}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1707
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1708 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
1709 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
1710 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
1711 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
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 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
1714 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
1715 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
1716 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
1717 \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
1718 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
1719 \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
1720
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1721 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
1722 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
1723 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
1724 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
1725 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
1726 \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
1727 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
1728
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1729 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
1730 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
1731 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
1732 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
1733 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
1734 \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
1735 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
1736
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1737 \begin{verbatim}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1738 class C:
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1739 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
1740 pass
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1741
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1742 c = C()
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1743 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
1744 \end{verbatim}
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 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
1747 information.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1748
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 \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
1751 \obindex{code}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1752
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1753 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
1754 ``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
1755 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
1756 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
1757 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
1758 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
1759 attribute.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1760 \bifuncindex{compile}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1761 \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
1762
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1763 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
1764 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
1765 \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
1766 \stindex{exec}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1767 \bifuncindex{eval}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1768
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1769 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
1770 information.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1771
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1772
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1773 \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
1774
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1775 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
1776 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
1777 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
1778 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
1779 \bifuncindex{type}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1780 \refstmodindex{types}
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 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
1783
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1784
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1785 \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
1786
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1787 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
1788 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
1789 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
1790
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1791 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
1792
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1793
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1794 \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
1795
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1796 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
1797 \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
1798 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
1799 \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
1800
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1801 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
1802
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
1803 \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
1804
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1805 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
1806 \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
1807 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
1808 (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
1809 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
1810 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
1811 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
1812 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
1813
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in
Guido van Rossum <guido@python.org>
parents: 22241
diff changeset
1814 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
1815 \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
1816 \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
1817 \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
1818
20767
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become
Fred Drake <fdrake@acm.org>
parents: 20764
diff changeset
1819
10156
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable
Fred Drake <fdrake@acm.org>
parents: 10147
diff changeset
1820 \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
1821
11463
17e12305973e Use \citetitle and \programopt as appropriate.
Fred Drake <fdrake@acm.org>
parents: 11183
diff changeset
1822 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
1823 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
1824 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
1825
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1826
9083
bc41e86c938c Markup nits.
Fred Drake <fdrake@acm.org>
parents: 9034
diff changeset
1827 \subsection{Special Attributes \label{specialattrs}}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
1828
8a306dfd9f33 Move files around to get the names to match the module names except for
Fred Drake <fdrake@acm.org>
parents:
diff changeset
1829 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
1830 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
1831 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
1832
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1833 \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
1834 A dictionary or other mapping object used to store an
9083
bc41e86c938c Markup nits.
Fred Drake <fdrake@acm.org>
parents: 9034
diff changeset
1835 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
1836 \end{memberdesc}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
1837
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1838 \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
1839 \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
1840 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
1841 \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
1842
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1843 \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
1844 \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
1845 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
1846 \end{memberdesc}
8730
8a306dfd9f33 Move files around to get the names to match the module names except for
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parents:
diff changeset
1847
15383
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1848 \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
1849 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
1850 \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
1851
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed
Fred Drake <fdrake@acm.org>
parents: 15332
diff changeset
1852 \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
1853 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
1854 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
1855 \end{memberdesc}
32070
b319db3869d8 add note about the __name__ read-only attribute
Fred Drake <fdrake@acm.org>
parents: 31631
diff changeset
1856
b319db3869d8 add note about the __name__ read-only attribute
Fred Drake <fdrake@acm.org>
parents: 31631
diff changeset
1857 \begin{memberdesc}[class]{__name__}
b319db3869d8 add note about the __name__ read-only attribute
Fred Drake <fdrake@acm.org>
parents: 31631
diff changeset
1858 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
1859 \end{memberdesc}