cpython-lru_cache-weakref: Doc/lib/libstdtypes.tex annotate

annotate Doc/lib/libstdtypes.tex @ 30706:be0ca26ad574 2.3

Patch #825679: Clarify semantics of .isfoo on empty strings.

author	Martin v. Löwis <martin@v.loewis.de>
date	Sat, 18 Oct 2003 09:54:38 +0000
parents	04bcfdcf290a
children	6fdde96a7222

rev	line source
9083 bc41e86c938c Markup nits. Fred Drake <fdrake@acm.org> parents: 9034 diff changeset	1 \section{Built-in Types \label{types}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	2
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	3 The following sections describe the standard types that are built into
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	4 the interpreter. Historically, Python's built-in types have differed
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	5 from user-defined types because it was not possible to use the built-in
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	6 types as the basis for object-oriented inheritance. With the 2.2
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	7 release this situation has started to change, although the intended
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	8 unification of user-defined and built-in types is as yet far from
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	9 complete.
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	10
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	11 The principal built-in types are numerics, sequences, mappings, files
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	12 classes, instances and exceptions.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	13 \indexii{built-in}{types}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	14
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	15 Some operations are supported by several object types; in particular,
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	16 all objects can be compared, tested for truth value, and converted to
9558 fa867d8ee7eb Remove some remaining {\rm ...} constructs. Fred Drake <fdrake@acm.org> parents: 9523 diff changeset	17 a string (with the \code{`\textrm{\ldots}`} notation). The latter
fa867d8ee7eb Remove some remaining {\rm ...} constructs. Fred Drake <fdrake@acm.org> parents: 9523 diff changeset	18 conversion is implicitly used when an object is written by the
fa867d8ee7eb Remove some remaining {\rm ...} constructs. Fred Drake <fdrake@acm.org> parents: 9523 diff changeset	19 \keyword{print}\stindex{print} statement.
28909 06abfc9c68e7 At the site of an indexed reference to print, point to the relevant Fred Drake <fdrake@acm.org> parents: 28606 diff changeset	20 (Information on \ulink{\keyword{print} statement}{../ref/print.html}
06abfc9c68e7 At the site of an indexed reference to print, point to the relevant Fred Drake <fdrake@acm.org> parents: 28606 diff changeset	21 and other language statements can be found in the
06abfc9c68e7 At the site of an indexed reference to print, point to the relevant Fred Drake <fdrake@acm.org> parents: 28606 diff changeset	22 \citetitle[../ref/ref.html]{Python Reference Manual} and the
06abfc9c68e7 At the site of an indexed reference to print, point to the relevant Fred Drake <fdrake@acm.org> parents: 28606 diff changeset	23 \citetitle[../tut/tut.html]{Python Tutorial}.)
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	24
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	25
28909 06abfc9c68e7 At the site of an indexed reference to print, point to the relevant Fred Drake <fdrake@acm.org> parents: 28606 diff changeset	26 \subsection{Truth Value Testing\label{truth}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	27
9558 fa867d8ee7eb Remove some remaining {\rm ...} constructs. Fred Drake <fdrake@acm.org> parents: 9523 diff changeset	28 Any object can be tested for truth value, for use in an \keyword{if} or
fa867d8ee7eb Remove some remaining {\rm ...} constructs. Fred Drake <fdrake@acm.org> parents: 9523 diff changeset	29 \keyword{while} condition or as operand of the Boolean operations below.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	30 The following values are considered false:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	31 \stindex{if}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	32 \stindex{while}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	33 \indexii{truth}{value}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	34 \indexii{Boolean}{operations}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	35 \index{false}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	36
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	37 \begin{itemize}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	38
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	39 \item \code{None}
24631 110c6edaf62f Clarify that the bool instances are acceptable return values from Fred Drake <fdrake@acm.org> parents: 24599 diff changeset	40 \withsubitem{(Built-in object)}{\ttindex{None}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	41
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	42 \item \code{False}
24631 110c6edaf62f Clarify that the bool instances are acceptable return values from Fred Drake <fdrake@acm.org> parents: 24599 diff changeset	43 \withsubitem{(Built-in object)}{\ttindex{False}}
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	44
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	45 \item zero of any numeric type, for example, \code{0}, \code{0L},
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	46 \code{0.0}, \code{0j}.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	47
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	48 \item any empty sequence, for example, \code{''}, \code{()}, \code{[]}.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	49
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	50 \item any empty mapping, for example, \code{\{\}}.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	51
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	52 \item instances of user-defined classes, if the class defines a
24631 110c6edaf62f Clarify that the bool instances are acceptable return values from Fred Drake <fdrake@acm.org> parents: 24599 diff changeset	53 \method{__nonzero__()} or \method{__len__()} method, when that
110c6edaf62f Clarify that the bool instances are acceptable return values from Fred Drake <fdrake@acm.org> parents: 24599 diff changeset	54 method returns the integer zero or \class{bool} value
110c6edaf62f Clarify that the bool instances are acceptable return values from Fred Drake <fdrake@acm.org> parents: 24599 diff changeset	55 \code{False}.\footnote{Additional
24227 8a67f28a42a5 Clarify the return value of __nonzero__(): It must be an integer. Fred Drake <fdrake@acm.org> parents: 23860 diff changeset	56 information on these special methods may be found in the
8a67f28a42a5 Clarify the return value of __nonzero__(): It must be an integer. Fred Drake <fdrake@acm.org> parents: 23860 diff changeset	57 \citetitle[../ref/ref.html]{Python Reference Manual}.}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	58
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	59 \end{itemize}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	60
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	61 All other values are considered true --- so objects of many types are
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	62 always true.
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	63 \index{true}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	64
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	65 Operations and built-in functions that have a Boolean result always
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	66 return \code{0} or \code{False} for false and \code{1} or \code{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	67 for true, unless otherwise stated. (Important exception: the 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	68 operations \samp{or}\opindex{or} and \samp{and}\opindex{and} always
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in Guido van Rossum <guido@python.org> parents: 22241 diff changeset	69 return one of their operands.)
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in Guido van Rossum <guido@python.org> parents: 22241 diff changeset	70 \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	71 \index{True}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	72
9083 bc41e86c938c Markup nits. Fred Drake <fdrake@acm.org> parents: 9034 diff changeset	73 \subsection{Boolean Operations \label{boolean}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	74
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	75 These are the Boolean operations, ordered by ascending priority:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	76 \indexii{Boolean}{operations}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	77
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	78 \begin{tableiii}{c\|l\|c}{code}{Operation}{Result}{Notes}
16285 15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	79 \lineiii{\var{x} or \var{y}}
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	80 {if \var{x} is false, then \var{y}, else \var{x}}{(1)}
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	81 \lineiii{\var{x} and \var{y}}
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	82 {if \var{x} is false, then \var{x}, else \var{y}}{(1)}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	83 \hline
16285 15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	84 \lineiii{not \var{x}}
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	85 {if \var{x} is false, then \code{True}, else \code{False}}{(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	86 \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	87 \opindex{and}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	88 \opindex{or}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	89 \opindex{not}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	90
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	91 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	92 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	93
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	94 \begin{description}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	95
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	96 \item[(1)]
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	97 These only evaluate their second argument if needed for their outcome.
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	98
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	99 \item[(2)]
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	100 \samp{not} has a lower priority than non-Boolean operators, so
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	101 \code{not \var{a} == \var{b}} is interpreted as \code{not (\var{a} ==
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	102 \var{b})}, and \code{\var{a} == not \var{b}} is a syntax error.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	103
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	104 \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	105
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	106
9083 bc41e86c938c Markup nits. Fred Drake <fdrake@acm.org> parents: 9034 diff changeset	107 \subsection{Comparisons \label{comparisons}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	108
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	109 Comparison operations are supported by all objects. They all have the
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	110 same priority (which is higher than that of the Boolean operations).
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	111 Comparisons can be chained arbitrarily; for example, \code{\var{x} <
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	112 \var{y} <= \var{z}} is equivalent to \code{\var{x} < \var{y} and
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	113 \var{y} <= \var{z}}, except that \var{y} is evaluated only once (but
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	114 in both cases \var{z} is not evaluated at all when \code{\var{x} <
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	115 \var{y}} is found to be false).
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	116 \indexii{chaining}{comparisons}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	117
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	118 This table summarizes the comparison operations:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	119
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	120 \begin{tableiii}{c\|l\|c}{code}{Operation}{Meaning}{Notes}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	121 \lineiii{<}{strictly less than}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	122 \lineiii{<=}{less than or equal}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	123 \lineiii{>}{strictly greater than}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	124 \lineiii{>=}{greater than or equal}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	125 \lineiii{==}{equal}{}
14044 a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange() Fred Drake <fdrake@acm.org> parents: 13967 diff changeset	126 \lineiii{!=}{not equal}{(1)}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	127 \lineiii{<>}{not equal}{(1)}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	128 \lineiii{is}{object identity}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	129 \lineiii{is not}{negated object identity}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	130 \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	131 \indexii{operator}{comparison}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	132 \opindex{==} % XXX All others have funny characters < ! >
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	133 \opindex{is}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	134 \opindex{is not}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	135
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	136 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	137 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	138
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	139 \begin{description}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	140
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	141 \item[(1)]
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	142 \code{<>} and \code{!=} are alternate spellings for the same operator.
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	143 \code{!=} is the preferred spelling; \code{<>} is obsolescent.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	144
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	145 \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	146
29343 e4f70e602598 Patch #744238: Explain that different string types also may compare equal. Martin v. Löwis <martin@v.loewis.de> parents: 29067 diff changeset	147 Objects of different types, except different numeric types and different string types, never
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	148 compare equal; such objects are ordered consistently but arbitrarily
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	149 (so that sorting a heterogeneous array yields a consistent result).
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	150 Furthermore, some types (for example, file objects) support only a
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	151 degenerate notion of comparison where any two objects of that type are
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	152 unequal. Again, such objects are ordered arbitrarily but
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	153 consistently. The \code{<}, \code{<=}, \code{>} and \code{>=}
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	154 operators will raise a \exception{TypeError} exception when any operand
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	155 is a complex number.
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	156 \indexii{object}{numeric}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	157 \indexii{objects}{comparing}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	158
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	159 Instances of a class normally compare as non-equal unless the class
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	160 \withsubitem{(instance method)}{\ttindex{__cmp__()}}
14485 ac0246586d52 Improve a couple of references to the language reference, making them Fred Drake <fdrake@acm.org> parents: 14044 diff changeset	161 defines the \method{__cmp__()} method. Refer to the
ac0246586d52 Improve a couple of references to the language reference, making them Fred Drake <fdrake@acm.org> parents: 14044 diff changeset	162 \citetitle[../ref/customization.html]{Python Reference Manual} for
ac0246586d52 Improve a couple of references to the language reference, making them Fred Drake <fdrake@acm.org> parents: 14044 diff changeset	163 information on the use of this method to effect object comparisons.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	164
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	165 \strong{Implementation note:} Objects of different types except
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	166 numbers are ordered by their type names; objects of the same types
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	167 that don't support proper comparison are ordered by their address.
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	168
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	169 Two more operations with the same syntactic priority,
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	170 \samp{in}\opindex{in} and \samp{not in}\opindex{not in}, are supported
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	171 only by sequence types (below).
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	172
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	173
9083 bc41e86c938c Markup nits. Fred Drake <fdrake@acm.org> parents: 9034 diff changeset	174 \subsection{Numeric Types \label{typesnumeric}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	175
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	176 There are four distinct numeric types: \dfn{plain integers},
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in Guido van Rossum <guido@python.org> parents: 22241 diff changeset	177 \dfn{long integers},
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	178 \dfn{floating point numbers}, and \dfn{complex numbers}.
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	179 In addition, Booleans are a subtype of plain integers.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	180 Plain integers (also just called \dfn{integers})
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	181 are implemented using \ctype{long} in C, which gives them at least 32
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	182 bits of precision. Long integers have unlimited precision. Floating
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	183 point numbers are implemented using \ctype{double} in C. All bets on
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	184 their precision are off unless you happen to know the machine you are
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	185 working with.
15005 0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	186 \obindex{numeric}
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	187 \obindex{Boolean}
15005 0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	188 \obindex{integer}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	189 \obindex{long integer}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	190 \obindex{floating point}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	191 \obindex{complex number}
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	192 \indexii{C}{language}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	193
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	194 Complex numbers have a real and imaginary part, which are each
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	195 implemented using \ctype{double} in C. To extract these parts from
22241 7584b6f1afde Change Windows file.truncate() to (a) restore the original file position, Tim Peters <tim.peters@gmail.com> parents: 22214 diff changeset	196 a complex number \var{z}, use \code{\var{z}.real} and \code{\var{z}.imag}.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	197
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	198 Numbers are created by numeric literals or as the result of built-in
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	199 functions and operators. Unadorned integer literals (including hex
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	200 and octal numbers) yield plain integers unless the value they denote
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	201 is too large to be represented as a plain integer, in which case
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	202 they yield a long integer. Integer literals with an
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	203 \character{L} or \character{l} suffix yield long integers
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	204 (\character{L} is preferred because \samp{1l} looks too much like
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	205 eleven!). Numeric literals containing a decimal point or an exponent
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	206 sign yield floating point numbers. Appending \character{j} or
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	207 \character{J} to a numeric literal yields a complex number with a
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	208 zero real part. A complex numeric literal is the sum of a real and
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	209 an imaginary part.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	210 \indexii{numeric}{literals}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	211 \indexii{integer}{literals}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	212 \indexiii{long}{integer}{literals}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	213 \indexii{floating point}{literals}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	214 \indexii{complex number}{literals}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	215 \indexii{hexadecimal}{literals}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	216 \indexii{octal}{literals}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	217
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	218 Python fully supports mixed arithmetic: when a binary arithmetic
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	219 operator has operands of different numeric types, the operand with the
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	220 ``narrower'' type is widened to that of the other, where plain
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	221 integer is narrower than long integer is narrower than floating point is
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	222 narrower than complex.
10520 7ee1e3134147 Fixed latex2html weirdness with footnotes. Fred Drake <fdrake@acm.org> parents: 10241 diff changeset	223 Comparisons between numbers of mixed type use the same rule.\footnote{
7ee1e3134147 Fixed latex2html weirdness with footnotes. Fred Drake <fdrake@acm.org> parents: 10241 diff changeset	224 As a consequence, the list \code{[1, 2]} is considered equal
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	225 to \code{[1.0, 2.0]}, and similarly for tuples.
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	226 } The constructors \function{int()}, \function{long()}, \function{float()},
9558 fa867d8ee7eb Remove some remaining {\rm ...} constructs. Fred Drake <fdrake@acm.org> parents: 9523 diff changeset	227 and \function{complex()} can be used
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	228 to produce numbers of a specific type.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	229 \index{arithmetic}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	230 \bifuncindex{int}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	231 \bifuncindex{long}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	232 \bifuncindex{float}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	233 \bifuncindex{complex}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	234
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	235 All numeric types (except complex) support the following operations,
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	236 sorted by ascending priority (operations in the same box have the same
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	237 priority; all numeric operations have a higher priority than
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	238 comparison operations):
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	239
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	240 \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	241 \lineiii{\var{x} + \var{y}}{sum of \var{x} and \var{y}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	242 \lineiii{\var{x} - \var{y}}{difference of \var{x} and \var{y}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	243 \hline
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	244 \lineiii{\var{x} * \var{y}}{product of \var{x} and \var{y}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	245 \lineiii{\var{x} / \var{y}}{quotient of \var{x} and \var{y}}{(1)}
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	246 \lineiii{\var{x} \%{} \var{y}}{remainder of \code{\var{x} / \var{y}}}{(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	247 \hline
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	248 \lineiii{-\var{x}}{\var{x} negated}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	249 \lineiii{+\var{x}}{\var{x} unchanged}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	250 \hline
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	251 \lineiii{abs(\var{x})}{absolute value or magnitude of \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	252 \lineiii{int(\var{x})}{\var{x} converted to integer}{(2)}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	253 \lineiii{long(\var{x})}{\var{x} converted to long integer}{(2)}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	254 \lineiii{float(\var{x})}{\var{x} converted to floating point}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	255 \lineiii{complex(\var{re},\var{im})}{a complex number with real part \var{re}, imaginary part \var{im}. \var{im} defaults to zero.}{}
10147 3ac7f0066375 Document <complex #>.conjugate(). Fred Drake <fdrake@acm.org> parents: 9558 diff changeset	256 \lineiii{\var{c}.conjugate()}{conjugate of the complex number \var{c}}{}
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	257 \lineiii{divmod(\var{x}, \var{y})}{the pair \code{(\var{x} / \var{y}, \var{x} \%{} \var{y})}}{(3)(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	258 \lineiii{pow(\var{x}, \var{y})}{\var{x} to the power \var{y}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	259 \lineiii{\var{x} ** \var{y}}{\var{x} to the power \var{y}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	260 \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	261 \indexiii{operations on}{numeric}{types}
10147 3ac7f0066375 Document <complex #>.conjugate(). Fred Drake <fdrake@acm.org> parents: 9558 diff changeset	262 \withsubitem{(complex number method)}{\ttindex{conjugate()}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	263
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	264 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	265 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	266 \begin{description}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	267
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	268 \item[(1)]
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	269 For (plain or long) integer division, the result is an integer.
22241 7584b6f1afde Change Windows file.truncate() to (a) restore the original file position, Tim Peters <tim.peters@gmail.com> parents: 22214 diff changeset	270 The result is always rounded towards minus infinity: 1/2 is 0,
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	271 (-1)/2 is -1, 1/(-2) is -1, and (-1)/(-2) is 0. Note that the result
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	272 is a long integer if either operand is a long integer, regardless of
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	273 the numeric value.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	274 \indexii{integer}{division}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	275 \indexiii{long}{integer}{division}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	276
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	277 \item[(2)]
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	278 Conversion from floating point to (long or plain) integer may round or
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	279 truncate as in C; see functions \function{floor()} and
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	280 \function{ceil()} in the \refmodule{math}\refbimodindex{math} module
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	281 for well-defined conversions.
10156 0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	282 \withsubitem{(in module math)}{\ttindex{floor()}\ttindex{ceil()}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	283 \indexii{numeric}{conversions}
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	284 \indexii{C}{language}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	285
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	286 \item[(3)]
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	287 See section \ref{built-in-funcs}, ``Built-in Functions,'' for a full
e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	288 description.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	289
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	290 \item[(4)]
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	291 Complex floor division operator, modulo operator, and \function{divmod()}.
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	292
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	293 \deprecated{2.3}{Instead convert to float using \function{abs()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	294 if appropriate.}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	295
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	296 \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	297 % XXXJH exceptions: overflow (when? what operations?) zerodivision
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	298
10241 f138ba72bf2d Update description of what modules "look like" when printed. Fred Drake <fdrake@acm.org> parents: 10156 diff changeset	299 \subsubsection{Bit-string Operations on Integer Types \label{bitstring-ops}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	300 \nodename{Bit-string Operations}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	301
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	302 Plain and long integer types support additional operations that make
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	303 sense only for bit-strings. Negative numbers are treated as their 2's
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	304 complement value (for long integers, this assumes a sufficiently large
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	305 number of bits that no overflow occurs during the operation).
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	306
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	307 The priorities of the binary bit-wise operations are all lower than
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	308 the numeric operations and higher than the comparisons; the unary
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	309 operation \samp{\~} has the same priority as the other unary numeric
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	310 operations (\samp{+} and \samp{-}).
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	311
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	312 This table lists the bit-string operations sorted in ascending
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	313 priority (operations in the same box have the same priority):
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	314
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	315 \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	316 \lineiii{\var{x} \| \var{y}}{bitwise \dfn{or} of \var{x} and \var{y}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	317 \lineiii{\var{x} \^{} \var{y}}{bitwise \dfn{exclusive or} of \var{x} and \var{y}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	318 \lineiii{\var{x} \&{} \var{y}}{bitwise \dfn{and} of \var{x} and \var{y}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	319 \lineiii{\var{x} << \var{n}}{\var{x} shifted left by \var{n} bits}{(1), (2)}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	320 \lineiii{\var{x} >> \var{n}}{\var{x} shifted right by \var{n} bits}{(1), (3)}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	321 \hline
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	322 \lineiii{\~\var{x}}{the bits of \var{x} inverted}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	323 \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	324 \indexiii{operations on}{integer}{types}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	325 \indexii{bit-string}{operations}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	326 \indexii{shifting}{operations}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	327 \indexii{masking}{operations}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	328
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	329 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	330 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	331 \begin{description}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	332 \item[(1)] Negative shift counts are illegal and cause a
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	333 \exception{ValueError} to be raised.
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	334 \item[(2)] A left shift by \var{n} bits is equivalent to
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	335 multiplication by \code{pow(2, \var{n})} without overflow check.
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	336 \item[(3)] A right shift by \var{n} bits is equivalent to
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	337 division by \code{pow(2, \var{n})} without overflow check.
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	338 \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	339
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	340
17658 d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	341 \subsection{Iterator Types \label{typeiter}}
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	342
17663 d76649bd38d0 The general iteration support is part of 2.2, not 2.1 -- fixed the version Fred Drake <fdrake@acm.org> parents: 17658 diff changeset	343 \versionadded{2.2}
17658 d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	344 \index{iterator protocol}
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	345 \index{protocol!iterator}
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	346 \index{sequence!iteration}
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	347 \index{container!iteration over}
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	348
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	349 Python supports a concept of iteration over containers. This is
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	350 implemented using two distinct methods; these are used to allow
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	351 user-defined classes to support iteration. Sequences, described below
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	352 in more detail, always support the iteration methods.
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	353
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	354 One method needs to be defined for container objects to provide
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	355 iteration support:
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	356
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	357 \begin{methoddesc}[container]{__iter__}{}
18839 ab8aa4302109 Typo fix. Greg Ward <gward@python.net> parents: 18829 diff changeset	358 Return an iterator object. The object is required to support the
17658 d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	359 iterator protocol described below. If a container supports
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	360 different types of iteration, additional methods can be provided to
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	361 specifically request iterators for those iteration types. (An
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	362 example of an object supporting multiple forms of iteration would be
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	363 a tree structure which supports both breadth-first and depth-first
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	364 traversal.) This method corresponds to the \member{tp_iter} slot of
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	365 the type structure for Python objects in the Python/C API.
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	366 \end{methoddesc}
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	367
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	368 The iterator objects themselves are required to support the following
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	369 two methods, which together form the \dfn{iterator protocol}:
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	370
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	371 \begin{methoddesc}[iterator]{__iter__}{}
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	372 Return the iterator object itself. This is required to allow both
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	373 containers and iterators to be used with the \keyword{for} and
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	374 \keyword{in} statements. This method corresponds to the
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	375 \member{tp_iter} slot of the type structure for Python objects in
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	376 the Python/C API.
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	377 \end{methoddesc}
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	378
17663 d76649bd38d0 The general iteration support is part of 2.2, not 2.1 -- fixed the version Fred Drake <fdrake@acm.org> parents: 17658 diff changeset	379 \begin{methoddesc}[iterator]{next}{}
17658 d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	380 Return the next item from the container. If there are no further
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	381 items, raise the \exception{StopIteration} exception. This method
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	382 corresponds to the \member{tp_iternext} slot of the type structure
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	383 for Python objects in the Python/C API.
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	384 \end{methoddesc}
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	385
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	386 Python defines several iterator objects to support iteration over
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	387 general and specific sequence types, dictionaries, and other more
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	388 specialized forms. The specific types are not important beyond their
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	389 implementation of the iterator protocol.
d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	390
24253 62f4b45b05fd Record the decision that StopIteration is a sink state (see recent Guido van Rossum <guido@python.org> parents: 24227 diff changeset	391 The intention of the protocol is that once an iterator's
62f4b45b05fd Record the decision that StopIteration is a sink state (see recent Guido van Rossum <guido@python.org> parents: 24227 diff changeset	392 \method{next()} method raises \exception{StopIteration}, it will
62f4b45b05fd Record the decision that StopIteration is a sink state (see recent Guido van Rossum <guido@python.org> parents: 24227 diff changeset	393 continue to do so on subsequent calls. Implementations that
62f4b45b05fd Record the decision that StopIteration is a sink state (see recent Guido van Rossum <guido@python.org> parents: 24227 diff changeset	394 do not obey this property are deemed broken. (This constraint
62f4b45b05fd Record the decision that StopIteration is a sink state (see recent Guido van Rossum <guido@python.org> parents: 24227 diff changeset	395 was added in Python 2.3; in Python 2.2, various iterators are
62f4b45b05fd Record the decision that StopIteration is a sink state (see recent Guido van Rossum <guido@python.org> parents: 24227 diff changeset	396 broken according to this rule.)
62f4b45b05fd Record the decision that StopIteration is a sink state (see recent Guido van Rossum <guido@python.org> parents: 24227 diff changeset	397
29590 8807e901c526 SF bug #696777: How to make a class iterable using a member generator. Raymond Hettinger <python@rcn.com> parents: 29516 diff changeset	398 Python's generators provide a convenient way to implement the
8807e901c526 SF bug #696777: How to make a class iterable using a member generator. Raymond Hettinger <python@rcn.com> parents: 29516 diff changeset	399 iterator protocol. If a container object's \method{__iter__()}
8807e901c526 SF bug #696777: How to make a class iterable using a member generator. Raymond Hettinger <python@rcn.com> parents: 29516 diff changeset	400 method is implemented as a generator, it will automatically
8807e901c526 SF bug #696777: How to make a class iterable using a member generator. Raymond Hettinger <python@rcn.com> parents: 29516 diff changeset	401 return an iterator object (technically, a generator object)
8807e901c526 SF bug #696777: How to make a class iterable using a member generator. Raymond Hettinger <python@rcn.com> parents: 29516 diff changeset	402 supplying the \method{__iter__()} and \method{next()} methods.
8807e901c526 SF bug #696777: How to make a class iterable using a member generator. Raymond Hettinger <python@rcn.com> parents: 29516 diff changeset	403
17658 d6498b1ef50d Added section describing the iterator protocol. Fred Drake <fdrake@acm.org> parents: 17616 diff changeset	404
9083 bc41e86c938c Markup nits. Fred Drake <fdrake@acm.org> parents: 9034 diff changeset	405 \subsection{Sequence Types \label{typesseq}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	406
13967 7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach Fred Drake <fdrake@acm.org> parents: 13933 diff changeset	407 There are six sequence types: strings, Unicode strings, lists,
14044 a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange() Fred Drake <fdrake@acm.org> parents: 13967 diff changeset	408 tuples, buffers, and xrange 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	409
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	410 String literals are written in single or double quotes:
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	411 \code{'xyzzy'}, \code{"frobozz"}. See chapter 2 of the
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	412 \citetitle[../ref/strings.html]{Python Reference Manual} for more about
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	413 string literals. Unicode strings are much like strings, but are
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	414 specified in the syntax using a preceeding \character{u} character:
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	415 \code{u'abc'}, \code{u"def"}. Lists are constructed with square brackets,
11463 17e12305973e Use \citetitle and \programopt as appropriate. Fred Drake <fdrake@acm.org> parents: 11183 diff changeset	416 separating items with commas: \code{[a, b, c]}. Tuples are
17e12305973e Use \citetitle and \programopt as appropriate. Fred Drake <fdrake@acm.org> parents: 11183 diff changeset	417 constructed by the comma operator (not within square brackets), with
17e12305973e Use \citetitle and \programopt as appropriate. Fred Drake <fdrake@acm.org> parents: 11183 diff changeset	418 or without enclosing parentheses, but an empty tuple must have the
30376 3edcce0efc54 Fix spacing markup and other sundries. Raymond Hettinger <python@rcn.com> parents: 30251 diff changeset	419 enclosing parentheses, such as \code{a, b, c} or \code{()}. A single
3edcce0efc54 Fix spacing markup and other sundries. Raymond Hettinger <python@rcn.com> parents: 30251 diff changeset	420 item tuple must have a trailing comma, such as \code{(d,)}.
15005 0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	421 \obindex{sequence}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	422 \obindex{string}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	423 \obindex{Unicode}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	424 \obindex{tuple}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	425 \obindex{list}
18395 1d0d3e6a3201 List constraints on xrange() objects. Guido van Rossum <guido@python.org> parents: 18391 diff changeset	426
1d0d3e6a3201 List constraints on xrange() objects. Guido van Rossum <guido@python.org> parents: 18391 diff changeset	427 Buffer objects are not directly supported by Python syntax, but can be
1d0d3e6a3201 List constraints on xrange() objects. Guido van Rossum <guido@python.org> parents: 18391 diff changeset	428 created by calling the builtin function
25393 f559e97a41be Remove spurious period. Fred Drake <fdrake@acm.org> parents: 24902 diff changeset	429 \function{buffer()}.\bifuncindex{buffer} They don't support
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	430 concatenation or repetition.
18395 1d0d3e6a3201 List constraints on xrange() objects. Guido van Rossum <guido@python.org> parents: 18391 diff changeset	431 \obindex{buffer}
1d0d3e6a3201 List constraints on xrange() objects. Guido van Rossum <guido@python.org> parents: 18391 diff changeset	432
1d0d3e6a3201 List constraints on xrange() objects. Guido van Rossum <guido@python.org> parents: 18391 diff changeset	433 Xrange objects are similar to buffers in that there is no specific
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	434 syntax to create them, but they are created using the \function{xrange()}
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	435 function.\bifuncindex{xrange} They don't support slicing,
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	436 concatenation or repetition, and using \code{in}, \code{not in},
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	437 \function{min()} or \function{max()} on them is inefficient.
15005 0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	438 \obindex{xrange}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	439
18395 1d0d3e6a3201 List constraints on xrange() objects. Guido van Rossum <guido@python.org> parents: 18391 diff changeset	440 Most sequence types support the following operations. The \samp{in} 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	441 \samp{not in} operations have the same priorities as the comparison
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	442 operations. The \samp{+} and \samp{*} operations have the same
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	443 priority as the corresponding numeric operations.\footnote{They must
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	444 have since the parser can't tell the type of the operands.}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	445
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	446 This table lists the sequence operations sorted in ascending priority
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	447 (operations in the same box have the same priority). In the table,
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	448 \var{s} and \var{t} are sequences of the same type; \var{n}, \var{i}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	449 and \var{j} are integers:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	450
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	451 \begin{tableiii}{c\|l\|c}{code}{Operation}{Result}{Notes}
24598 12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	452 \lineiii{\var{x} in \var{s}}{\code{1} if an item of \var{s} is equal to \var{x}, else \code{0}}{(1)}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	453 \lineiii{\var{x} not in \var{s}}{\code{0} if an item of \var{s} is
24598 12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	454 equal to \var{x}, else \code{1}}{(1)}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	455 \hline
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	456 \lineiii{\var{s} + \var{t}}{the concatenation of \var{s} and \var{t}}{}
24598 12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	457 \lineiii{\var{s} * \var{n}\textrm{,} \var{n} * \var{s}}{\var{n} shallow copies of \var{s} concatenated}{(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	458 \hline
24598 12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	459 \lineiii{\var{s}[\var{i}]}{\var{i}'th item of \var{s}, origin 0}{(3)}
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	460 \lineiii{\var{s}[\var{i}:\var{j}]}{slice of \var{s} from \var{i} to \var{j}}{(3), (4)}
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	461 \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)}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	462 \hline
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	463 \lineiii{len(\var{s})}{length of \var{s}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	464 \lineiii{min(\var{s})}{smallest item of \var{s}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	465 \lineiii{max(\var{s})}{largest item of \var{s}}{}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	466 \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	467 \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	468 \bifuncindex{len}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	469 \bifuncindex{min}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	470 \bifuncindex{max}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	471 \indexii{concatenation}{operation}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	472 \indexii{repetition}{operation}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	473 \indexii{subscript}{operation}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	474 \indexii{slice}{operation}
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	475 \indexii{extended slice}{operation}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	476 \opindex{in}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	477 \opindex{not in}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	478
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	479 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	480 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	481
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	482 \begin{description}
24598 12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	483 \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 Barry Warsaw <barry@python.org> parents: 24459 diff changeset	484 \code{in} and \code{not in} operations act like a substring test. In
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	485 Python versions before 2.3, \var{x} had to be a string of length 1.
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	486 In Python 2.3 and beyond, \var{x} may be a string of any length.
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	487
12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	488 \item[(2)] Values of \var{n} less than \code{0} are treated as
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	489 \code{0} (which yields an empty sequence of the same type as
19529 dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	490 \var{s}). Note also that the copies are shallow; nested structures
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	491 are not copied. This often haunts new Python programmers; consider:
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	492
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	493 \begin{verbatim}
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	494 >>> lists = [[]] * 3
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	495 >>> lists
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	496 [[], [], []]
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	497 >>> lists[0].append(3)
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	498 >>> lists
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	499 [[3], [3], [3]]
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	500 \end{verbatim}
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	501
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	502 What has happened is that \code{lists} is a list containing three
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	503 copies of the list \code{[[]]} (a one-element list containing an
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	504 empty list), but the contained list is shared by each copy. You can
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	505 create a list of different lists this way:
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	506
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	507 \begin{verbatim}
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	508 >>> lists = [[] for i in range(3)]
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	509 >>> lists[0].append(3)
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	510 >>> lists[1].append(5)
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	511 >>> lists[2].append(7)
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	512 >>> lists
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	513 [[3], [5], [7]]
dd8d6153a8c6 Added explanation that [...] * n generates shallow copies of [...], so Fred Drake <fdrake@acm.org> parents: 19243 diff changeset	514 \end{verbatim}
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	515
24598 12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	516 \item[(3)] If \var{i} or \var{j} is negative, the index is relative to
18416 33b4357aebb8 Fix up a few style nits -- avoid "e.g." and "i.e." -- these make Fred Drake <fdrake@acm.org> parents: 18395 diff changeset	517 the end of the string: \code{len(\var{s}) + \var{i}} or
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	518 \code{len(\var{s}) + \var{j}} is substituted. But note that \code{-0} is
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	519 still \code{0}.
22241 7584b6f1afde Change Windows file.truncate() to (a) restore the original file position, Tim Peters <tim.peters@gmail.com> parents: 22214 diff changeset	520
24598 12e146171f3d Committing patch #591250 which provides "str1 in str2" when str1 is a Barry Warsaw <barry@python.org> parents: 24459 diff changeset	521 \item[(4)] The slice of \var{s} from \var{i} to \var{j} is defined as
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	522 the sequence of items with index \var{k} such that \code{\var{i} <=
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	523 \var{k} < \var{j}}. If \var{i} or \var{j} is greater than
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	524 \code{len(\var{s})}, use \code{len(\var{s})}. If \var{i} is omitted,
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	525 use \code{0}. If \var{j} is omitted, use \code{len(\var{s})}. If
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	526 \var{i} is greater than or equal to \var{j}, the slice is empty.
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	527
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	528 \item[(5)] The slice of \var{s} from \var{i} to \var{j} with step
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	529 \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	530 \code{\var{x} = \var{i} + \var{n}*\var{k}} such that \code{0}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	531 \code{<=} \var{n} \code{<} \code{abs(i-j)}. If \var{i} or \var{j}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	532 is greater than \code{len(\var{s})}, use \code{len(\var{s})}. If
30251 0dfafaa10401 SF patch #797180: Bug 792656: slicing explained Raymond Hettinger <python@rcn.com> parents: 30095 diff changeset	533 \var{i} or \var{j} are omitted then they become ``end'' values
0dfafaa10401 SF patch #797180: Bug 792656: slicing explained Raymond Hettinger <python@rcn.com> parents: 30095 diff changeset	534 (which end depends on the sign of \var{k}). Note, \var{k} cannot
0dfafaa10401 SF patch #797180: Bug 792656: slicing explained Raymond Hettinger <python@rcn.com> parents: 30095 diff changeset	535 be zero.
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	536
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	537 \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	538
10156 0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	539
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	540 \subsubsection{String Methods \label{string-methods}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	541
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	542 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	543 objects support:
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	544
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	545 \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	546 Return a copy of the string with only its first character capitalized.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	547 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	548
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	549 \begin{methoddesc}[string]{center}{width}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	550 Return centered in a string of length \var{width}. Padding is done
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	551 using spaces.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	552 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	553
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	554 \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	555 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	556 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	557 \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	558 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	559
21332 fbbd8a4ca7a6 Added documentation for str.decode(). Fred Drake <fdrake@acm.org> parents: 21177 diff changeset	560 \begin{methoddesc}[string]{decode}{\optional{encoding\optional{, errors}}}
fbbd8a4ca7a6 Added documentation for str.decode(). Fred Drake <fdrake@acm.org> parents: 21177 diff changeset	561 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	562 \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	563 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	564 \code{'strict'}, meaning that encoding errors raise
fbbd8a4ca7a6 Added documentation for str.decode(). Fred Drake <fdrake@acm.org> parents: 21177 diff changeset	565 \exception{ValueError}. Other possible values are \code{'ignore'} and
fbbd8a4ca7a6 Added documentation for str.decode(). Fred Drake <fdrake@acm.org> parents: 21177 diff changeset	566 \code{replace'}.
fbbd8a4ca7a6 Added documentation for str.decode(). Fred Drake <fdrake@acm.org> parents: 21177 diff changeset	567 \versionadded{2.2}
fbbd8a4ca7a6 Added documentation for str.decode(). Fred Drake <fdrake@acm.org> parents: 21177 diff changeset	568 \end{methoddesc}
fbbd8a4ca7a6 Added documentation for str.decode(). Fred Drake <fdrake@acm.org> parents: 21177 diff changeset	569
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	570 \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	571 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	572 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	573 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	574 \code{'strict'}, meaning that encoding errors raise a
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	575 \exception{ValueError}. Other possible values are \code{'ignore'} and
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	576 \code{'replace'}.
15332 12aec3381c94 Marc-Andre Lemburg <mal@lemburg.com> noted that the encode() string method Fred Drake <fdrake@acm.org> parents: 15005 diff changeset	577 \versionadded{2.0}
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	578 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	579
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	580 \begin{methoddesc}[string]{endswith}{suffix\optional{, start\optional{, end}}}
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	581 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	582 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	583 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	584 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	585
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	586 \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	587 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	588 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	589 characters is assumed.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	590 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	591
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	592 \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	593 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	594 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	595 \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	596 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	597 not found.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	598 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	599
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	600 \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	601 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	602 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	603 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	604
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	605 \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	606 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	607 is at least one character, false otherwise.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	608 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	609
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	610 \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	611 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	612 is at least one character, false otherwise.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	613 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	614
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	615 \begin{methoddesc}[string]{isdigit}{}
30706 be0ca26ad574 Patch #825679: Clarify semantics of .isfoo on empty strings. Martin v. Löwis <martin@v.loewis.de> parents: 30704 diff changeset	616 Return true if all characters in the string are digits and there
be0ca26ad574 Patch #825679: Clarify semantics of .isfoo on empty strings. Martin v. Löwis <martin@v.loewis.de> parents: 30704 diff changeset	617 is at least one character, false otherwise.
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	618 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	619
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	620 \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	621 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	622 there is at least one cased character, false otherwise.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	623 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	624
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	625 \begin{methoddesc}[string]{isspace}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	626 Return true if there are only whitespace characters in the string and
30706 be0ca26ad574 Patch #825679: Clarify semantics of .isfoo on empty strings. Martin v. Löwis <martin@v.loewis.de> parents: 30704 diff changeset	627 there is at least one character, false otherwise.
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	628 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	629
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	630 \begin{methoddesc}[string]{istitle}{}
30706 be0ca26ad574 Patch #825679: Clarify semantics of .isfoo on empty strings. Martin v. Löwis <martin@v.loewis.de> parents: 30704 diff changeset	631 Return true if the string is a titlecased string and there is at least one
be0ca26ad574 Patch #825679: Clarify semantics of .isfoo on empty strings. Martin v. Löwis <martin@v.loewis.de> parents: 30704 diff changeset	632 character, i.e. uppercase characters may only follow uncased
be0ca26ad574 Patch #825679: Clarify semantics of .isfoo on empty strings. Martin v. Löwis <martin@v.loewis.de> parents: 30704 diff changeset	633 characters and lowercase characters only cased ones. Return false
be0ca26ad574 Patch #825679: Clarify semantics of .isfoo on empty strings. Martin v. Löwis <martin@v.loewis.de> parents: 30704 diff changeset	634 otherwise.
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	635 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	636
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	637 \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	638 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	639 there is at least one cased character, false otherwise.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	640 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	641
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	642 \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	643 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	644 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	645 providing this method.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	646 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	647
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	648 \begin{methoddesc}[string]{ljust}{width}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	649 Return the string left justified in a string of length \var{width}.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	650 Padding is done using spaces. The original string is returned if
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	651 \var{width} is less than \code{len(\var{s})}.
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]{lower}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	655 Return a copy of the string converted to lowercase.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	656 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	657
23017 44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string Fred Drake <fdrake@acm.org> parents: 22994 diff changeset	658 \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	659 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	660 \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	661 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	662 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	663 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	664 \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	665 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	666
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	667 \begin{methoddesc}[string]{replace}{old, new\optional{, maxsplit}}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	668 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	669 \var{old} replaced by \var{new}. If the optional argument
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	670 \var{maxsplit} is given, only the first \var{maxsplit} occurrences are
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	671 replaced.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	672 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	673
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	674 \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	675 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	676 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	677 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	678 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	679 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	680
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	681 \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	682 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	683 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	684 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	685
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	686 \begin{methoddesc}[string]{rjust}{width}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	687 Return the string right justified in a string of length \var{width}.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	688 Padding is done using spaces. The original string is returned if
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	689 \var{width} is less than \code{len(\var{s})}.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	690 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	691
23017 44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string Fred Drake <fdrake@acm.org> parents: 22994 diff changeset	692 \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	693 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	694 \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	695 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	696 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	697 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	698 \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	699 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	700
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	701 \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	702 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	703 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	704 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	705 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	706 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	707
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	708 \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	709 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	710 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	711 \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	712 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	713
23017 44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string Fred Drake <fdrake@acm.org> parents: 22994 diff changeset	714 \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	715 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	716 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	717 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	718 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	719 position.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	720 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	721
23017 44637bd7f59b Document the optional argument to the .strip(), .rstrip(), .strip() string Fred Drake <fdrake@acm.org> parents: 22994 diff changeset	722 \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	723 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	724 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	725 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	726 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	727 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	728 \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	729 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	730
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	731 \begin{methoddesc}[string]{swapcase}{}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	732 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	733 lowercase and vice versa.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	734 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	735
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	736 \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	737 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	738 characters, all remaining cased characters are lowercase.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	739 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	740
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	741 \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	742 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	743 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	744 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	745 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	746
e9dddfd2a62f Discussion of signatures for unicode.translate() and str.translate() Raymond Hettinger <python@rcn.com> parents: 29590 diff changeset	747 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	748 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	749 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	750 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	751 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	752 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	753 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	754 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	755 \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	756 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	757
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	758 \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	759 Return a copy of the string converted to uppercase.
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	760 \end{methoddesc}
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	761
23045 8b1268bc371a Apply the second version of SF patch http://www.python.org/sf/536241 Walter Dörwald <walter@livinglogic.de> parents: 23017 diff changeset	762 \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	763 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	764 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	765 \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	766 \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	767 \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	768
13933 4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	769
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	770 \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	771
21177 7d1eac41ce3e Slightly improved indexing for the string-% operator, thanks to comments Fred Drake <fdrake@acm.org> parents: 21163 diff changeset	772 \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	773 \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	774 \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	775 \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	776 \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	777 \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	778 \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	779 \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	780
16285 15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	781 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	782 \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	783 \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	784 \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	785 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	786 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	787 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	788 \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	789 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	790 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	791
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	792 If \var{format} requires a single argument, \var{values} may be a
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	793 single non-tuple object. \footnote{To format only a tuple you
63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	794 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	795 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	796 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	797 single mapping object (for example, a dictionary).
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	798
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	799 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	800 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	801
16285 15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	802 \begin{enumerate}
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	803 \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	804 specifier.
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	805 \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	806 of characters (for example, \code{(somename)}).
16285 15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	807 \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	808 conversion types.
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	809 \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	810 \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	811 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	812 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	813 precision.
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	814 \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	815 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	816 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	817 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	818 the precision.
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	819 \item Length modifier (optional).
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	820 \item Conversion type.
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	821 \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	822
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	823 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	824 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	825 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	826 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	827 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	828
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	829 \begin{verbatim}
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	830 >>> 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	831 {'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	832 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	833 \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	834
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	835 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	836 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	837
16285 15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	838 The conversion flag characters are:
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	839
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	840 \begin{tableii}{c\|l}{character}{Flag}{Meaning}
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	841 \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	842 (where defined below).}
27919 4b5c2e025c5e Fix SF bug #687655, String formatting conversions misleading Neal Norwitz <nnorwitz@gmail.com> parents: 27225 diff changeset	843 \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	844 \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	845 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	846 \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	847 (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	848 \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	849 precede the conversion (overrides a "space" flag).}
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	850 \end{tableii}
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	851
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	852 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	853 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	854
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	855 The conversion types are:
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	856
25906 50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	857 \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	858 \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	859 \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	860 \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	861 \lineiii{u}{Unsigned decimal.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	862 \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	863 \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	864 \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	865 \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	866 \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	867 \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	868 \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	869 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	870 \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	871 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	872 \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	873 string).}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	874 \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	875 \function{repr()}).}{(3)}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	876 \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	877 \function{str()}).}{(4)}
25906 50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	878 \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	879 character in the result.}{}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	880 \end{tableiii}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	881
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	882 \noindent
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	883 Notes:
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	884 \begin{description}
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	885 \item[(1)]
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	886 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	887 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	888 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	889 zero.
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	890 \item[(2)]
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	891 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	892 (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	893 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	894 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	895 not already a zero.
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	896 \item[(3)]
50905db35da5 - The "-" format flag overrides the "0" flag, not the "-" flag. Fred Drake <fdrake@acm.org> parents: 25393 diff changeset	897 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	898 \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	899 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	900 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	901 \end{description}
16285 15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	902
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	903 % XXX Examples?
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	904
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	905 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	906 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	907
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	908 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	909 \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	910 are replaced by \code{\%g} conversions.\footnote{
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	911 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	912 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	913 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	914 point values on a particular machine.
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	915 } All other errors raise exceptions.
15e0c10092bb Massively improved documentation for string formatting operations, Fred Drake <fdrake@acm.org> parents: 15926 diff changeset	916
21163 7b6879714b74 Make no assumption about how modules are built when referring to them; this Fred Drake <fdrake@acm.org> parents: 21159 diff changeset	917 Additional string operations are defined in standard modules
7b6879714b74 Make no assumption about how modules are built when referring to them; this Fred Drake <fdrake@acm.org> parents: 21159 diff changeset	918 \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	919 \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	920
13967 7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach Fred Drake <fdrake@acm.org> parents: 13933 diff changeset	921
14044 a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange() Fred Drake <fdrake@acm.org> parents: 13967 diff changeset	922 \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	923
15005 0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	924 The xrange\obindex{xrange} type is an immutable sequence which is
14044 a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange() Fred Drake <fdrake@acm.org> parents: 13967 diff changeset	925 commonly used for looping. The advantage of the xrange type is that an
a905c5aa0691 As pointed out by Denis S. Otkidach <den@analyt.chem.msu.ru>, xrange() Fred Drake <fdrake@acm.org> parents: 13967 diff changeset	926 xrange object will always take the same amount of memory, no matter the
13967 7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach Fred Drake <fdrake@acm.org> parents: 13933 diff changeset	927 size of the range it represents. There are no consistent performance
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach Fred Drake <fdrake@acm.org> parents: 13933 diff changeset	928 advantages.
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach Fred Drake <fdrake@acm.org> parents: 13933 diff changeset	929
26592 0c646baeec58 Update comments about the performance of xrange(). Raymond Hettinger <python@rcn.com> parents: 26514 diff changeset	930 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	931 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	932
7b7ee58901fb Document the range type, as suggested by Denis S. Otkidach Fred Drake <fdrake@acm.org> parents: 13933 diff changeset	933
10156 0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	934 \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	935
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	936 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	937 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	938 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	939 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	940 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	941 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	942 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	943 \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	944 \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	945 \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	946
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	947 \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	948 \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	949 {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	950 \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	951 {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	952 \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	953 {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	954 \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	955 {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	956 \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	957 {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	958 \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	959 {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	960 \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	961 {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	962 \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	963 {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	964 \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	965 {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	966 \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	967 \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	968 {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	969 \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	970 {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	971 \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	972 {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	973 \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	974 {reverses the items of \var{s} in place}{(7)}
27036 41f7726e3e51 Allow list sort's comparison function to explicitly be None. See SF patch Skip Montanaro <skip@pobox.com> parents: 26816 diff changeset	975 \lineiii{\var{s}.sort(\optional{\var{cmpfunc=None}})}
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	976 {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	977 \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	978 \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	979 \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	980 \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	981 \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	982 \indexii{slice}{assignment}
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	983 \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	984 \stindex{del}
10156 0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	985 \withsubitem{(list method)}{
11183 1e0b1967be7f In note mentioning [].remove()'s exception, tell what exception is Fred Drake <fdrake@acm.org> parents: 11100 diff changeset	986 \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	987 \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	988 \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	989 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	990 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	991 \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	992 \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	993 replacing.
23778 245224d1b8c9 This is my nearly two year old patch Michael W. Hudson <mwh@python.net> parents: 23515 diff changeset	994
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	995 \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	996 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	997 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	998 deprecated since Python 1.4.
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	999
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1000 \item[(3)] Raises an exception when \var{x} is not a list object. The
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1001 \method{extend()} method is experimental and not supported by
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1002 mutable sequence types other than lists.
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1003
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1004 \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	1005 \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	1006 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	1007 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	1008 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	1009 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	1010
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1011 \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	1012 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	1013 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	1014 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	1015 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	1016
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1017 \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	1018 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	1019 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	1020
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1021 \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	1022 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	1023 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	1024 the sorted or reversed list.
12223 e82e82b3b9ad Merged changes from the 1.5.2p2 release. Fred Drake <fdrake@acm.org> parents: 11463 diff changeset	1025
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1026 \item[(8)] The \method{sort()} method takes an optional argument
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1027 specifying a comparison function of two arguments (list items) which
20173 f100793ca9af The list.sort() docs require a function that returns -1, 0 or +1. That's Tim Peters <tim.peters@gmail.com> parents: 20045 diff changeset	1028 should return a negative, zero or positive number depending on whether
11183 1e0b1967be7f In note mentioning [].remove()'s exception, tell what exception is Fred Drake <fdrake@acm.org> parents: 11100 diff changeset	1029 the first argument is considered smaller than, equal to, or larger
1e0b1967be7f In note mentioning [].remove()'s exception, tell what exception is Fred Drake <fdrake@acm.org> parents: 11100 diff changeset	1030 than the second argument. Note that this slows the sorting process
28337 90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1031 down considerably; for example to sort a list in reverse order it is much
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1032 faster to call \method{sort()} followed by \method{reverse()}
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1033 than to use \method{sort()} with a comparison function that
27036 41f7726e3e51 Allow list sort's comparison function to explicitly be None. See SF patch Skip Montanaro <skip@pobox.com> parents: 26816 diff changeset	1034 reverses the ordering of the elements. Passing \constant{None} as the
41f7726e3e51 Allow list sort's comparison function to explicitly be None. See SF patch Skip Montanaro <skip@pobox.com> parents: 26816 diff changeset	1035 comparison function is semantically equivalent to calling
41f7726e3e51 Allow list sort's comparison function to explicitly be None. See SF patch Skip Montanaro <skip@pobox.com> parents: 26816 diff changeset	1036 \method{sort()} with no comparison function.
28337 90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1037 \versionchanged[Support for \code{None} as an equivalent to omitting
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1038 \var{cmpfunc} was added]{2.3}
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1039
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1040 As an example of using the \var{cmpfunc} argument to the
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1041 \method{sort()} method, consider sorting a list of sequences by the
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1042 second element of that list:
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1043
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1044 \begin{verbatim}
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1045 def mycmp(a, b):
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1046 return cmp(a[1], b[1])
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1047
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1048 mylist.sort(mycmp)
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1049 \end{verbatim}
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1050
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1051 A more time-efficient approach for reasonably-sized data structures can
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1052 often be used:
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1053
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1054 \begin{verbatim}
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1055 tmplist = [(x[1], x) for x in mylist]
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1056 tmplist.sort()
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1057 mylist = [x for (key, x) in tmplist]
90f17c374f59 - added example of using a comparison function with list.sort(), and Fred Drake <fdrake@acm.org> parents: 28211 diff changeset	1058 \end{verbatim}
24459 189eb6fa9ded Added new footnote about list.sort() stability. Repaired footnote about Tim Peters <tim.peters@gmail.com> parents: 24253 diff changeset	1059
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1060 \item[(9)] Whether the \method{sort()} method is stable is not defined by
24459 189eb6fa9ded Added new footnote about list.sort() stability. Repaired footnote about Tim Peters <tim.peters@gmail.com> parents: 24253 diff changeset	1061 the language (a sort is stable if it guarantees not to change the
189eb6fa9ded Added new footnote about list.sort() stability. Repaired footnote about Tim Peters <tim.peters@gmail.com> parents: 24253 diff changeset	1062 relative order of elements that compare equal). In the C
189eb6fa9ded Added new footnote about list.sort() stability. Repaired footnote about Tim Peters <tim.peters@gmail.com> parents: 24253 diff changeset	1063 implementation of Python, sorts were stable only by accident through
189eb6fa9ded Added new footnote about list.sort() stability. Repaired footnote about Tim Peters <tim.peters@gmail.com> parents: 24253 diff changeset	1064 Python 2.2. The C implementation of Python 2.3 introduced a stable
189eb6fa9ded Added new footnote about list.sort() stability. Repaired footnote about Tim Peters <tim.peters@gmail.com> parents: 24253 diff changeset	1065 \method{sort()} method, but code that intends to be portable across
189eb6fa9ded Added new footnote about list.sort() stability. Repaired footnote about Tim Peters <tim.peters@gmail.com> parents: 24253 diff changeset	1066 implementations and versions must not rely on stability.
26161 dd10d97d329a SF patch 637176: list.sort crasher Tim Peters <tim.peters@gmail.com> parents: 25906 diff changeset	1067
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1068 \item[(10)] While a list is being sorted, the effect of attempting to
26161 dd10d97d329a SF patch 637176: list.sort crasher Tim Peters <tim.peters@gmail.com> parents: 25906 diff changeset	1069 mutate, or even inspect, the list is undefined. The C implementation
dd10d97d329a SF patch 637176: list.sort crasher Tim Peters <tim.peters@gmail.com> parents: 25906 diff changeset	1070 of Python 2.3 makes the list appear empty for the duration, and raises
dd10d97d329a SF patch 637176: list.sort crasher Tim Peters <tim.peters@gmail.com> parents: 25906 diff changeset	1071 \exception{ValueError} if it can detect that the list has been
dd10d97d329a SF patch 637176: list.sort crasher Tim Peters <tim.peters@gmail.com> parents: 25906 diff changeset	1072 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	1073 \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	1074
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1075
9083 bc41e86c938c Markup nits. Fred Drake <fdrake@acm.org> parents: 9034 diff changeset	1076 \subsection{Mapping Types \label{typesmapping}}
15005 0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	1077 \obindex{mapping}
0cf5111bf09c Use \obindex{...} instead of \indexii{...}{type} in many places; this is Fred Drake <fdrake@acm.org> parents: 14710 diff changeset	1078 \obindex{dictionary}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1079
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	1080 A \dfn{mapping} object maps immutable values to
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1081 arbitrary objects. Mappings are mutable objects. There is currently
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1082 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	1083 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	1084 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	1085 object identity) may not be used as keys.
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1086 Numeric types used for keys obey the normal rules for numeric
30414 e17c44c79b03 SF bug #804280: fromkeys is not listed in index Raymond Hettinger <python@rcn.com> parents: 30376 diff changeset	1087 comparison: if two numbers compare equal (such as \code{1} and
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1088 \code{1.0}) then they can be used interchangeably to index the same
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1089 dictionary entry.
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1090
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1091 Dictionaries are created by placing a comma-separated list of
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1092 \code{\var{key}: \var{value}} pairs within braces, for example:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1093 \code{\{'jack': 4098, 'sjoerd': 4127\}} or
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1094 \code{\{4098: 'jack', 4127: 'sjoerd'\}}.
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1095
10968 5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1096 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	1097 \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	1098 arbitrary objects):
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1099 \indexiii{operations on}{mapping}{types}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1100 \indexiii{operations on}{dictionary}{type}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1101 \stindex{del}
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1102 \bifuncindex{len}
10156 0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	1103 \withsubitem{(dictionary method)}{
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	1104 \ttindex{clear()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	1105 \ttindex{copy()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	1106 \ttindex{has_key()}
30414 e17c44c79b03 SF bug #804280: fromkeys is not listed in index Raymond Hettinger <python@rcn.com> parents: 30376 diff changeset	1107 \ttindex{fromkeys()}
10156 0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	1108 \ttindex{items()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	1109 \ttindex{keys()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	1110 \ttindex{update()}
0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	1111 \ttindex{values()}
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1112 \ttindex{get()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1113 \ttindex{setdefault()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1114 \ttindex{pop()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1115 \ttindex{popitem()}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1116 \ttindex{iteritems()}
29067 04065c4a1c6b Missing parenthesis found by texcheck.py Raymond Hettinger <python@rcn.com> parents: 29065 diff changeset	1117 \ttindex{iterkeys()}
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1118 \ttindex{itervalues()}}
10968 5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1119
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1120 \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	1121 \lineiii{len(\var{a})}{the number of items in \var{a}}{}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1122 \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	1123 \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	1124 {set \code{\var{a}[\var{k}]} to \var{v}}
10968 5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1125 {}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1126 \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	1127 {remove \code{\var{a}[\var{k}]} from \var{a}}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1128 {(1)}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1129 \lineiii{\var{a}.clear()}{remove all items from \code{a}}{}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1130 \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	1131 \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	1132 {\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	1133 {}
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	1134 \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	1135 {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	1136 {(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	1137 \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	1138 {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	1139 {(2)}
10968 5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1140 \lineiii{\var{a}.items()}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1141 {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	1142 {(3)}
18085 7e459fb3c332 Fixed reference to table notes for {}.keys() and {}.items() -- these Fred Drake <fdrake@acm.org> parents: 17966 diff changeset	1143 \lineiii{\var{a}.keys()}{a copy of \var{a}'s list of keys}{(3)}
10968 5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1144 \lineiii{\var{a}.update(\var{b})}
26437 57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class Raymond Hettinger <python@rcn.com> parents: 26260 diff changeset	1145 {\code{for \var{k} in \var{b}.keys(): \var{a}[\var{k}] = \var{b}[\var{k}]}}
18286 bc05a95242a3 Remove the restriction on a mapping's .update() method. Barry Warsaw <barry@python.org> parents: 18085 diff changeset	1146 {}
26437 57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class Raymond Hettinger <python@rcn.com> parents: 26260 diff changeset	1147 \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	1148 {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	1149 {(7)}
18085 7e459fb3c332 Fixed reference to table notes for {}.keys() and {}.items() -- these Fred Drake <fdrake@acm.org> parents: 17966 diff changeset	1150 \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	1151 \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	1152 {\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	1153 else \var{x}}
18286 bc05a95242a3 Remove the restriction on a mapping's .update() method. Barry Warsaw <barry@python.org> parents: 18085 diff changeset	1154 {(4)}
13894 77b9e041b595 Barry's patch to document the new setdefault() method. Slightly Guido van Rossum <guido@python.org> parents: 13780 diff changeset	1155 \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	1156 {\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	1157 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	1158 {(5)}
28211 92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop Raymond Hettinger <python@rcn.com> parents: 28171 diff changeset	1159 \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	1160 {\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	1161 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	1162 {(8)}
15522 aaa54752e4ba "Documentation" for {}.popitem(). Guido van Rossum <guido@python.org> parents: 15463 diff changeset	1163 \lineiii{\var{a}.popitem()}
aaa54752e4ba "Documentation" for {}.popitem(). Guido van Rossum <guido@python.org> parents: 15463 diff changeset	1164 {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	1165 {(6)}
17966 178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues() Fred Drake <fdrake@acm.org> parents: 17663 diff changeset	1166 \lineiii{\var{a}.iteritems()}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues() Fred Drake <fdrake@acm.org> parents: 17663 diff changeset	1167 {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	1168 {(2), (3)}
17966 178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues() Fred Drake <fdrake@acm.org> parents: 17663 diff changeset	1169 \lineiii{\var{a}.iterkeys()}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues() Fred Drake <fdrake@acm.org> parents: 17663 diff changeset	1170 {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	1171 {(2), (3)}
17966 178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues() Fred Drake <fdrake@acm.org> parents: 17663 diff changeset	1172 \lineiii{\var{a}.itervalues()}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues() Fred Drake <fdrake@acm.org> parents: 17663 diff changeset	1173 {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	1174 {(2), (3)}
10968 5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1175 \end{tableiii}
5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1176
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1177 \noindent
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1178 Notes:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1179 \begin{description}
10968 5ba2e4ce58cb Some clarifications on operations for mapping types, based on comments Fred Drake <fdrake@acm.org> parents: 10785 diff changeset	1180 \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	1181 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	1182
17966 178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues() Fred Drake <fdrake@acm.org> parents: 17663 diff changeset	1183 \item[(2)] \versionadded{2.2}
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues() Fred Drake <fdrake@acm.org> parents: 17663 diff changeset	1184
178bedf9536d Add descriptions of {}.iteritems(), {}.iterkeys(), and {}.itervalues() Fred Drake <fdrake@acm.org> parents: 17663 diff changeset	1185 \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	1186 \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	1187 \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	1188 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	1189 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	1190 \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	1191 \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	1192 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	1193 \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	1194 \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	1195 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	1196 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	1197
18286 bc05a95242a3 Remove the restriction on a mapping's .update() method. Barry Warsaw <barry@python.org> parents: 18085 diff changeset	1198 \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	1199 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	1200 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	1201
18286 bc05a95242a3 Remove the restriction on a mapping's .update() method. Barry Warsaw <barry@python.org> parents: 18085 diff changeset	1202 \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	1203 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	1204 the dictionary as the value of \var{k}.
15522 aaa54752e4ba "Documentation" for {}.popitem(). Guido van Rossum <guido@python.org> parents: 15463 diff changeset	1205
18286 bc05a95242a3 Remove the restriction on a mapping's .update() method. Barry Warsaw <barry@python.org> parents: 18085 diff changeset	1206 \item[(6)] \function{popitem()} is useful to destructively iterate
15522 aaa54752e4ba "Documentation" for {}.popitem(). Guido van Rossum <guido@python.org> parents: 15463 diff changeset	1207 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	1208
26437 57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class Raymond Hettinger <python@rcn.com> parents: 26260 diff changeset	1209 \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	1210 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	1211
92e3b611dc9f SF patch #693753: fix for bug 639806: default for dict.pop Raymond Hettinger <python@rcn.com> parents: 28171 diff changeset	1212 \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	1213 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	1214 \end{description}
57d03375aead SF Patch 643443. Added dict.fromkeys(iterable, value=None), a class Raymond Hettinger <python@rcn.com> parents: 26260 diff changeset	1215
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1216
20767 b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1217 \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	1218 \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	1219
20767 b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1220 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	1221 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	1222 \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	1223 \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	1224 is new in Python 2.2. The older built-in \function{open()} is an
37b8d92e12f5 Mention the new file() builtin in the section on file objects. Tim Peters <tim.peters@gmail.com> parents: 20701 diff changeset	1225 alias for \function{file()}.}
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	1226 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	1227 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	1228 \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	1229 \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	1230 \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	1231 \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	1232
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1233 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	1234 \exception{IOError} is raised. This includes situations where the
fa867d8ee7eb Remove some remaining {\rm ...} constructs. Fred Drake <fdrake@acm.org> parents: 9523 diff changeset	1235 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	1236 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	1237
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1238 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	1239
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1240
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1241 \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	1242 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	1243 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	1244 \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	1245 \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	1246 \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	1247
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1248 \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	1249 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	1250 \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	1251 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	1252 \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	1253
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1254 \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	1255 \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	1256 \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	1257 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	1258 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	1259 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	1260 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	1261 \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	1262 \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	1263 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	1264 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	1265 \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	1266
24599 d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and Guido van Rossum <guido@python.org> parents: 24598 diff changeset	1267 \begin{methoddesc}[file]{isatty}{}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and Guido van Rossum <guido@python.org> parents: 24598 diff changeset	1268 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	1269 \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	1270 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	1271 \end{methoddesc}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and Guido van Rossum <guido@python.org> parents: 24598 diff changeset	1272
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and Guido van Rossum <guido@python.org> parents: 24598 diff changeset	1273 \begin{methoddesc}[file]{next}{}
30414 e17c44c79b03 SF bug #804280: fromkeys is not listed in index Raymond Hettinger <python@rcn.com> parents: 30376 diff changeset	1274 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	1275 \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	1276 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	1277 \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	1278 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	1279 \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	1280 \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	1281 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	1282 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	1283 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	1284 \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	1285 \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	1286 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	1287 \versionadded{2.3}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and Guido van Rossum <guido@python.org> parents: 24598 diff changeset	1288 \end{methoddesc}
d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and Guido van Rossum <guido@python.org> parents: 24598 diff changeset	1289
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1290 \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	1291 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	1292 \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	1293 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	1294 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	1295 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	1296 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	1297 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	1298 C function \cfunction{fread()} more than once in an effort to
26672 8dd25a6f5913 Fixed bug Gustavo Niemeyer <gustavo@niemeyer.net> parents: 26592 diff changeset	1299 acquire as close to \var{size} bytes as possible. Also note that
8dd25a6f5913 Fixed bug Gustavo Niemeyer <gustavo@niemeyer.net> parents: 26592 diff changeset	1300 when in non-blocking mode, less data than what was requested may
8dd25a6f5913 Fixed bug Gustavo Niemeyer <gustavo@niemeyer.net> parents: 26592 diff changeset	1301 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	1302 \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	1303
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1304 \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	1305 Read one entire line from the file. A trailing newline character is
10520 7ee1e3134147 Fixed latex2html weirdness with footnotes. Fred Drake <fdrake@acm.org> parents: 10241 diff changeset	1306 kept in the string\footnote{
23860 63ee31bb25f3 Make a start at describing the results of class/type unification Steve Holden <steve@holdenweb.com> parents: 23847 diff changeset	1307 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	1308 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	1309 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	1310 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	1311 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	1312 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	1313 or not (yes this happens!).
4d14eef8ea07 Added Marc-Andre Lemburg's documentation for string methods, with some Fred Drake <fdrake@acm.org> parents: 13894 diff changeset	1314 } (but may be absent when a file ends with an
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1315 incomplete line). If the \var{size} argument is present and
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1316 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	1317 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	1318 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	1319 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	1320 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	1321 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	1322 \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	1323
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1324 \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	1325 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	1326 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	1327 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	1328 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	1329 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	1330 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	1331 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	1332 \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	1333
15926 ac13cef423c8 Document xreadlines() method. (Forgot to check this in before!) Guido van Rossum <guido@python.org> parents: 15896 diff changeset	1334 \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	1335 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	1336 \versionadded{2.1}
24599 d7ca0a2ce074 Document file.next(). Mark xreadlines obsolete (both method and Guido van Rossum <guido@python.org> parents: 24598 diff changeset	1337 \deprecated{2.3}{Use \code{for line in file} instead.}
15926 ac13cef423c8 Document xreadlines() method. (Forgot to check this in before!) Guido van Rossum <guido@python.org> parents: 15896 diff changeset	1338 \end{methoddesc}
ac13cef423c8 Document xreadlines() method. (Forgot to check this in before!) Guido van Rossum <guido@python.org> parents: 15896 diff changeset	1339
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1340 \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	1341 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	1342 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	1343 (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	1344 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	1345 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	1346 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	1347 \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	1348 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	1349 this method is essentially a no-op, but it remains useful for files
30704 04bcfdcf290a Patch #809535: Mention behaviour of seek on text files. Martin v. Löwis <martin@v.loewis.de> parents: 30414 diff changeset	1350 opened in append mode with reading enabled (mode \code{'a+'}). If the
04bcfdcf290a Patch #809535: Mention behaviour of seek on text files. Martin v. Löwis <martin@v.loewis.de> parents: 30414 diff changeset	1351 file is opened in text mode (mode \code{'t'}), only offsets returned
04bcfdcf290a Patch #809535: Mention behaviour of seek on text files. Martin v. Löwis <martin@v.loewis.de> parents: 30414 diff changeset	1352 by \method{tell()} are legal. Use of other offsets causes undefined
04bcfdcf290a Patch #809535: Mention behaviour of seek on text files. Martin v. Löwis <martin@v.loewis.de> parents: 30414 diff changeset	1353 behavior.
04bcfdcf290a Patch #809535: Mention behaviour of seek on text files. Martin v. Löwis <martin@v.loewis.de> parents: 30414 diff changeset	1354
04bcfdcf290a Patch #809535: Mention behaviour of seek on text files. Martin v. Löwis <martin@v.loewis.de> parents: 30414 diff changeset	1355 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	1356 \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	1357
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1358 \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	1359 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	1360 \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	1361 \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	1362
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1363 \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	1364 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	1365 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	1366 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	1367 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	1368 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	1369 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	1370 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	1371 undefined new content.
30376 3edcce0efc54 Fix spacing markup and other sundries. Raymond Hettinger <python@rcn.com> parents: 30251 diff changeset	1372 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	1373 \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	1374
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1375 \begin{methoddesc}[file]{write}{str}
20580 376ee174ecd0 Use the \note and \warning macros where appropriate. Fred Drake <fdrake@acm.org> parents: 20173 diff changeset	1376 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	1377 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	1378 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	1379 \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	1380
20045 7b8c11739714 Generalize file.writelines() to allow iterable objects. Tim Peters <tim.peters@gmail.com> parents: 20031 diff changeset	1381 \begin{methoddesc}[file]{writelines}{sequence}
7b8c11739714 Generalize file.writelines() to allow iterable objects. Tim Peters <tim.peters@gmail.com> parents: 20031 diff changeset	1382 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	1383 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	1384 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	1385 (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	1386 \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	1387 \end{methoddesc}
9e9556924b0a Added documentation for the xreadlines module & related changes. The Fred Drake <fdrake@acm.org> parents: 15731 diff changeset	1388
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
20031 e5a3f9d7766b Note that files are iterable; describe what the iterator returns. Fred Drake <fdrake@acm.org> parents: 19529 diff changeset	1390 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	1391 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	1392 \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	1393
e5a3f9d7766b Note that files are iterable; describe what the iterator returns. Fred Drake <fdrake@acm.org> parents: 19529 diff changeset	1394
14685 faf3e734254d Clarify a number of issues about the file-like object API based on Fred Drake <fdrake@acm.org> parents: 14557 diff changeset	1395 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	1396 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	1397 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	1398
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1399 \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	1400 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	1401 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	1402 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	1403 \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	1404
29065 bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine Martin v. Löwis <martin@v.loewis.de> parents: 28909 diff changeset	1405 \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	1406 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	1407 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	1408 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	1409 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	1410 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	1411 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	1412 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	1413 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	1414 strings.
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine Martin v. Löwis <martin@v.loewis.de> parents: 28909 diff changeset	1415
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine Martin v. Löwis <martin@v.loewis.de> parents: 28909 diff changeset	1416 \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	1417 \end{memberdesc}
bf1634b023d5 Patch #612627: Add encoding attribute to file objects, and determine Martin v. Löwis <martin@v.loewis.de> parents: 28909 diff changeset	1418
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1419 \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	1420 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	1421 \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	1422 \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	1423 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	1424 \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	1425
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1426 \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	1427 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	1428 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	1429 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	1430 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	1431 \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	1432
28171 24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1433 \begin{memberdesc}[file]{newlines}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1434 If Python was built with the \code{--with-universal-newlines} option
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1435 (the default) this read-only attribute exists, and for files opened in
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1436 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	1437 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	1438 \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	1439 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	1440 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	1441 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	1442 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	1443 \end{memberdesc}
24fe023901b0 Back in June in revision 1.98 Steve (accidentally, presumably) wiped Michael W. Hudson <mwh@python.net> parents: 27919 diff changeset	1444
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1445 \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	1446 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	1447 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	1448 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	1449 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	1450 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	1451 (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	1452 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	1453 \member{softspace} attribute.
20580 376ee174ecd0 Use the \note and \warning macros where appropriate. Fred Drake <fdrake@acm.org> parents: 20173 diff changeset	1454 \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	1455 \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	1456 \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	1457 \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	1458
15383 eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed Fred Drake <fdrake@acm.org> parents: 15332 diff changeset	1459
20767 b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1460 \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	1461
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1462 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	1463 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	1464
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1465
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1466 \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	1467
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1468 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	1469 \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	1470 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	1471 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	1472 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	1473 \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	1474 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	1475 \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	1476
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1477 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	1478 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	1479 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	1480 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	1481 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	1482 defines \code{\var{m}.a} to be \code{1}, but you can't write
29067 04065c4a1c6b Missing parenthesis found by texcheck.py Raymond Hettinger <python@rcn.com> parents: 29065 diff changeset	1483 \code{\var{m}.__dict__ = \{\}}).
20767 b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1484
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1485 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	1486 \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	1487 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	1488 '/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	1489
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1490
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1491 \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	1492 \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	1493
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1494 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	1495 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	1496
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1497
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1498 \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	1499
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1500 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	1501 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	1502 \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	1503
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1504 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	1505 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	1506 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	1507 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	1508
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1509 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	1510 \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	1511 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	1512 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	1513 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	1514 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	1515
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1516 Function objects also support getting and setting arbitrary
30414 e17c44c79b03 SF bug #804280: fromkeys is not listed in index Raymond Hettinger <python@rcn.com> parents: 30376 diff changeset	1517 attributes, which can be used, for example, to attach metadata to
e17c44c79b03 SF bug #804280: fromkeys is not listed in index Raymond Hettinger <python@rcn.com> parents: 30376 diff changeset	1518 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	1519 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	1520 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	1521 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	1522
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1523 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	1524 (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	1525 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	1526 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	1527 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	1528
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1529 \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	1530 \obindex{method}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1531
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1532 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	1533 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	1534 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	1535 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	1536
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1537 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	1538 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	1539 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	1540 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	1541 \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	1542 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	1543 \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	1544
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1545 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	1546 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	1547 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	1548 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	1549 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	1550 \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	1551 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	1552
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1553 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	1554 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	1555 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	1556 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	1557 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	1558 \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	1559 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	1560
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1561 \begin{verbatim}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1562 class C:
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1563 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	1564 pass
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1565
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1566 c = C()
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1567 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	1568 \end{verbatim}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1569
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1570 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	1571 information.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1572
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1573
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1574 \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	1575 \obindex{code}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1576
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1577 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	1578 ``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	1579 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	1580 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	1581 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	1582 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	1583 attribute.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1584 \bifuncindex{compile}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1585 \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	1586
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1587 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	1588 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	1589 \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	1590 \stindex{exec}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1591 \bifuncindex{eval}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1592
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1593 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	1594 information.
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1595
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1596
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1597 \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	1598
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1599 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	1600 accessed by the built-in function \function{type()}. There are no special
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1601 operations on types. The standard module \module{types} defines names
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1602 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	1603 \bifuncindex{type}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1604 \refstmodindex{types}
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1605
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1606 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	1607
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1608
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1609 \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	1610
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1611 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	1612 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	1613 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	1614
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1615 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	1616
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1617
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1618 \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	1619
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1620 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	1621 \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	1622 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	1623 \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	1624
b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1625 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	1626
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	1627 \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	1628
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in Guido van Rossum <guido@python.org> parents: 22241 diff changeset	1629 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	1630 \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	1631 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	1632 (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	1633 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	1634 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	1635 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	1636 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	1637
aa8d59823add Add the 'bool' type and its values 'False' and 'True', as described in Guido van Rossum <guido@python.org> parents: 22241 diff changeset	1638 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	1639 \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	1640 \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	1641 \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	1642
20767 b3f48c5d6e16 Promote file objects out of the "Other Objects" category, so they become Fred Drake <fdrake@acm.org> parents: 20764 diff changeset	1643
10156 0f7d694bc334 Make sure all HTML pages generated from this section have reasonable Fred Drake <fdrake@acm.org> parents: 10147 diff changeset	1644 \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	1645
11463 17e12305973e Use \citetitle and \programopt as appropriate. Fred Drake <fdrake@acm.org> parents: 11183 diff changeset	1646 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	1647 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	1648 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	1649
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1650
9083 bc41e86c938c Markup nits. Fred Drake <fdrake@acm.org> parents: 9034 diff changeset	1651 \subsection{Special Attributes \label{specialattrs}}
8730 8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1652
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1653 The implementation adds a few special read-only attributes to several
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1654 object types, where they are relevant:
8a306dfd9f33 Move files around to get the names to match the module names except for Fred Drake <fdrake@acm.org> parents: diff changeset	1655
15383 eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed Fred Drake <fdrake@acm.org> parents: 15332 diff changeset	1656 \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	1657 A dictionary or other mapping object used to store an
9083 bc41e86c938c Markup nits. Fred Drake <fdrake@acm.org> parents: 9034 diff changeset	1658 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	1659 \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	1660
15383 eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed Fred Drake <fdrake@acm.org> parents: 15332 diff changeset	1661 \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	1662 \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	1663 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	1664 \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	1665
15383 eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed Fred Drake <fdrake@acm.org> parents: 15332 diff changeset	1666 \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	1667 \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	1668 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	1669 \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	1670
15383 eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed Fred Drake <fdrake@acm.org> parents: 15332 diff changeset	1671 \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	1672 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	1673 \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	1674
eeb7c8a5b79f Document the proper exception to be raised by I/O operations on closed Fred Drake <fdrake@acm.org> parents: 15332 diff changeset	1675 \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	1676 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	1677 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	1678 \end{memberdesc}

Mercurial > cpython-lru_cache-weakref

annotate Doc/lib/libstdtypes.tex @ 30706:be0ca26ad574 2.3