cpython-lru_cache-weakref: Doc/library/struct.rst annotate

annotate Doc/library/struct.rst @ 58925:eecf1bef052d 2.6

Merged revisions 78207 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r78207 | ezio.melotti | 2010-02-17 01:26:09 +0200 (Wed, 17 Feb 2010) | 1 line #7930: fix stripid ........

author	Ezio Melotti <ezio.melotti@gmail.com>
date	Tue, 16 Feb 2010 23:29:44 +0000
parents	c8630f730907
children	c254e54ac856

rev	line source
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	1
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	2 :mod:`struct` --- Interpret strings as packed binary data
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	3 =========================================================
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	4
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	5 .. module:: struct
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	6 :synopsis: Interpret strings as packed binary data.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	7
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	8 .. index::
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	9 pair: C; structures
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	10 triple: packing; binary; data
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	11
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	12 This module performs conversions between Python values and C structs represented
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	13 as Python strings. It uses :dfn:`format strings` (explained below) as compact
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	14 descriptions of the lay-out of the C structs and the intended conversion to/from
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	15 Python values. This can be used in handling binary data stored in files or from
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	16 network connections, among other sources.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	17
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	18 The module defines the following exception and functions:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	19
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	20
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	21 .. exception:: error
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	22
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	23 Exception raised on various occasions; argument is a string describing what is
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	24 wrong.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	25
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	26
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	27 .. function:: pack(fmt, v1, v2, ...)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	28
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	29 Return a string containing the values ``v1, v2, ...`` packed according to the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	30 given format. The arguments must match the values required by the format
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	31 exactly.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	32
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	33
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	34 .. function:: pack_into(fmt, buffer, offset, v1, v2, ...)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	35
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	36 Pack the values ``v1, v2, ...`` according to the given format, write the packed
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	37 bytes into the writable buffer starting at offset. Note that the offset is
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	38 a required argument.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	39
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	40 .. versionadded:: 2.5
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	41
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	42
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	43 .. function:: unpack(fmt, string)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	44
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	45 Unpack the string (presumably packed by ``pack(fmt, ...)``) according to the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	46 given format. The result is a tuple even if it contains exactly one item. The
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	47 string must contain exactly the amount of data required by the format
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	48 (``len(string)`` must equal ``calcsize(fmt)``).
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	49
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	50
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	51 .. function:: unpack_from(fmt, buffer[,offset=0])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	52
56805 c8630f730907 Merged revisions 70171,70183,70290,70292,70315,70438,70464 via svnmerge from Georg Brandl <georg@python.org> parents: 47229 diff changeset	53 Unpack the buffer according to the given format. The result is a tuple even
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	54 if it contains exactly one item. The buffer must contain at least the amount
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	55 of data required by the format (``len(buffer[offset:])`` must be at least
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	56 ``calcsize(fmt)``).
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	57
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	58 .. versionadded:: 2.5
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	59
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	60
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	61 .. function:: calcsize(fmt)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	62
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	63 Return the size of the struct (and hence of the string) corresponding to the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	64 given format.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	65
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	66 Format characters have the following meaning; the conversion between C and
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	67 Python values should be obvious given their types:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	68
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	69 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	70 \| Format \| C Type \| Python \| Notes \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	71 +========+=========================+====================+=======+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	72 \| ``x`` \| pad byte \| no value \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	73 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	74 \| ``c`` \| :ctype:`char` \| string of length 1 \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	75 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	76 \| ``b`` \| :ctype:`signed char` \| integer \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	77 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	78 \| ``B`` \| :ctype:`unsigned char` \| integer \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	79 +--------+-------------------------+--------------------+-------+
45672 d41a4206405c Issue 1872: Changed the struct module typecode from 't' to '?', for Thomas Heller <theller@ctypes.org> parents: 44904 diff changeset	80 \| ``?`` \| :ctype:`_Bool` \| bool \| \(1) \|
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	81 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	82 \| ``h`` \| :ctype:`short` \| integer \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	83 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	84 \| ``H`` \| :ctype:`unsigned short` \| integer \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	85 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	86 \| ``i`` \| :ctype:`int` \| integer \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	87 +--------+-------------------------+--------------------+-------+
44904 063ed377fd3d Fix issue1789: The tutorial contained a misuse of the struct module. Gregory P. Smith <greg@mad-scientist.com> parents: 44383 diff changeset	88 \| ``I`` \| :ctype:`unsigned int` \| integer or long \| \|
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	89 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	90 \| ``l`` \| :ctype:`long` \| integer \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	91 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	92 \| ``L`` \| :ctype:`unsigned long` \| long \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	93 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	94 \| ``q`` \| :ctype:`long long` \| long \| \(2) \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	95 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	96 \| ``Q`` \| :ctype:`unsigned long \| long \| \(2) \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	97 \| \| long` \| \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	98 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	99 \| ``f`` \| :ctype:`float` \| float \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	100 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	101 \| ``d`` \| :ctype:`double` \| float \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	102 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	103 \| ``s`` \| :ctype:`char[]` \| string \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	104 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	105 \| ``p`` \| :ctype:`char[]` \| string \| \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	106 +--------+-------------------------+--------------------+-------+
44904 063ed377fd3d Fix issue1789: The tutorial contained a misuse of the struct module. Gregory P. Smith <greg@mad-scientist.com> parents: 44383 diff changeset	107 \| ``P`` \| :ctype:`void \*` \| long \| \|
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	108 +--------+-------------------------+--------------------+-------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	109
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	110 Notes:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	111
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	112 (1)
45672 d41a4206405c Issue 1872: Changed the struct module typecode from 't' to '?', for Thomas Heller <theller@ctypes.org> parents: 44904 diff changeset	113 The ``'?'`` conversion code corresponds to the :ctype:`_Bool` type defined by
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	114 C99. If this type is not available, it is simulated using a :ctype:`char`. In
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	115 standard mode, it is always represented by one byte.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	116
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	117 .. versionadded:: 2.6
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	118
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	119 (2)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	120 The ``'q'`` and ``'Q'`` conversion codes are available in native mode only if
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	121 the platform C compiler supports C :ctype:`long long`, or, on Windows,
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	122 :ctype:`__int64`. They are always available in standard modes.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	123
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	124 .. versionadded:: 2.2
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	125
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	126 A format character may be preceded by an integral repeat count. For example,
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	127 the format string ``'4h'`` means exactly the same as ``'hhhh'``.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	128
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	129 Whitespace characters between formats are ignored; a count and its format must
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	130 not contain whitespace though.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	131
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	132 For the ``'s'`` format character, the count is interpreted as the size of the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	133 string, not a repeat count like for the other format characters; for example,
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	134 ``'10s'`` means a single 10-byte string, while ``'10c'`` means 10 characters.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	135 For packing, the string is truncated or padded with null bytes as appropriate to
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	136 make it fit. For unpacking, the resulting string always has exactly the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	137 specified number of bytes. As a special case, ``'0s'`` means a single, empty
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	138 string (while ``'0c'`` means 0 characters).
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	139
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	140 The ``'p'`` format character encodes a "Pascal string", meaning a short
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	141 variable-length string stored in a fixed number of bytes. The count is the total
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	142 number of bytes stored. The first byte stored is the length of the string, or
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	143 255, whichever is smaller. The bytes of the string follow. If the string
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	144 passed in to :func:`pack` is too long (longer than the count minus 1), only the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	145 leading count-1 bytes of the string are stored. If the string is shorter than
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	146 count-1, it is padded with null bytes so that exactly count bytes in all are
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	147 used. Note that for :func:`unpack`, the ``'p'`` format character consumes count
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	148 bytes, but that the string returned can never contain more than 255 characters.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	149
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	150 For the ``'I'``, ``'L'``, ``'q'`` and ``'Q'`` format characters, the return
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	151 value is a Python long integer.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	152
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	153 For the ``'P'`` format character, the return value is a Python integer or long
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	154 integer, depending on the size needed to hold a pointer when it has been cast to
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	155 an integer type. A NULL pointer will always be returned as the Python integer
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	156 ``0``. When packing pointer-sized values, Python integer or long integer objects
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	157 may be used. For example, the Alpha and Merced processors use 64-bit pointer
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	158 values, meaning a Python long integer will be used to hold the pointer; other
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	159 platforms use 32-bit pointers and will use a Python integer.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	160
45672 d41a4206405c Issue 1872: Changed the struct module typecode from 't' to '?', for Thomas Heller <theller@ctypes.org> parents: 44904 diff changeset	161 For the ``'?'`` format character, the return value is either :const:`True` or
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	162 :const:`False`. When packing, the truth value of the argument object is used.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	163 Either 0 or 1 in the native or standard bool representation will be packed, and
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	164 any non-zero value will be True when unpacking.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	165
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	166 By default, C numbers are represented in the machine's native format and byte
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	167 order, and properly aligned by skipping pad bytes if necessary (according to the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	168 rules used by the C compiler).
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	169
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	170 Alternatively, the first character of the format string can be used to indicate
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	171 the byte order, size and alignment of the packed data, according to the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	172 following table:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	173
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	174 +-----------+------------------------+--------------------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	175 \| Character \| Byte order \| Size and alignment \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	176 +===========+========================+====================+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	177 \| ``@`` \| native \| native \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	178 +-----------+------------------------+--------------------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	179 \| ``=`` \| native \| standard \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	180 +-----------+------------------------+--------------------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	181 \| ``<`` \| little-endian \| standard \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	182 +-----------+------------------------+--------------------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	183 \| ``>`` \| big-endian \| standard \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	184 +-----------+------------------------+--------------------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	185 \| ``!`` \| network (= big-endian) \| standard \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	186 +-----------+------------------------+--------------------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	187
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	188 If the first character is not one of these, ``'@'`` is assumed.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	189
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	190 Native byte order is big-endian or little-endian, depending on the host system.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	191 For example, Motorola and Sun processors are big-endian; Intel and DEC
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	192 processors are little-endian.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	193
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	194 Native size and alignment are determined using the C compiler's
44383 3625234bf3d2 Some cleanup in the docs. Georg Brandl <georg@python.org> parents: 42775 diff changeset	195 ``sizeof`` expression. This is always combined with native byte order.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	196
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	197 Standard size and alignment are as follows: no alignment is required for any
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	198 type (so you have to use pad bytes); :ctype:`short` is 2 bytes; :ctype:`int` and
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	199 :ctype:`long` are 4 bytes; :ctype:`long long` (:ctype:`__int64` on Windows) is 8
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	200 bytes; :ctype:`float` and :ctype:`double` are 32-bit and 64-bit IEEE floating
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	201 point numbers, respectively. :ctype:`_Bool` is 1 byte.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	202
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	203 Note the difference between ``'@'`` and ``'='``: both use native byte order, but
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	204 the size and alignment of the latter is standardized.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	205
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	206 The form ``'!'`` is available for those poor souls who claim they can't remember
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	207 whether network byte order is big-endian or little-endian.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	208
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	209 There is no way to indicate non-native byte order (force byte-swapping); use the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	210 appropriate choice of ``'<'`` or ``'>'``.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	211
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	212 The ``'P'`` format character is only available for the native byte ordering
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	213 (selected as the default or with the ``'@'`` byte order character). The byte
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	214 order character ``'='`` chooses to use little- or big-endian ordering based on
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	215 the host system. The struct module does not interpret this as native ordering,
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	216 so the ``'P'`` format is not available.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	217
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	218 Examples (all using native byte order, size and alignment, on a big-endian
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	219 machine)::
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	220
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	221 >>> from struct import *
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	222 >>> pack('hhl', 1, 2, 3)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	223 '\x00\x01\x00\x02\x00\x00\x00\x03'
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	224 >>> unpack('hhl', '\x00\x01\x00\x02\x00\x00\x00\x03')
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	225 (1, 2, 3)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	226 >>> calcsize('hhl')
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	227 8
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	228
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	229 Hint: to align the end of a structure to the alignment requirement of a
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	230 particular type, end the format with the code for that type with a repeat count
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	231 of zero. For example, the format ``'llh0l'`` specifies two pad bytes at the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	232 end, assuming longs are aligned on 4-byte boundaries. This only works when
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	233 native size and alignment are in effect; standard size and alignment does not
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	234 enforce any alignment.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	235
47229 c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	236 Unpacked fields can be named by assigning them to variables or by wrapping
c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	237 the result in a named tuple::
c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	238
c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	239 >>> record = 'raymond \x32\x12\x08\x01\x08'
c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	240 >>> name, serialnum, school, gradelevel = unpack('<10sHHb', record)
c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	241
c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	242 >>> from collections import namedtuple
c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	243 >>> Student = namedtuple('Student', 'name serialnum school gradelevel')
c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	244 >>> Student._make(unpack('<10sHHb', s))
c5a85e4f9e86 Issue 2909: show how to name unpacked fields. Raymond Hettinger <python@rcn.com> parents: 46555 diff changeset	245 Student(name='raymond ', serialnum=4658, school=264, gradelevel=8)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	246
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	247 .. seealso::
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	248
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	249 Module :mod:`array`
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	250 Packed binary storage of homogeneous data.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	251
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	252 Module :mod:`xdrlib`
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	253 Packing and unpacking of XDR data.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	254
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	255
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	256 .. _struct-objects:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	257
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	258 Struct Objects
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	259 --------------
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	260
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	261 The :mod:`struct` module also defines the following type:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	262
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	263
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	264 .. class:: Struct(format)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	265
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	266 Return a new Struct object which writes and reads binary data according to the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	267 format string format. Creating a Struct object once and calling its methods
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	268 is more efficient than calling the :mod:`struct` functions with the same format
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	269 since the format string only needs to be compiled once.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	270
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	271 .. versionadded:: 2.5
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	272
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	273 Compiled Struct objects support the following methods and attributes:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	274
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	275
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	276 .. method:: pack(v1, v2, ...)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	277
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	278 Identical to the :func:`pack` function, using the compiled format.
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	279 (``len(result)`` will equal :attr:`self.size`.)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	280
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	281
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	282 .. method:: pack_into(buffer, offset, v1, v2, ...)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	283
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	284 Identical to the :func:`pack_into` function, using the compiled format.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	285
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	286
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	287 .. method:: unpack(string)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	288
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	289 Identical to the :func:`unpack` function, using the compiled format.
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	290 (``len(string)`` must equal :attr:`self.size`).
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	291
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	292
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	293 .. method:: unpack_from(buffer[, offset=0])
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	294
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	295 Identical to the :func:`unpack_from` function, using the compiled format.
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	296 (``len(buffer[offset:])`` must be at least :attr:`self.size`).
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	297
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	298
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	299 .. attribute:: format
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	300
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	301 The format string used to construct this Struct object.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	302
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	303 .. attribute:: size
42775 d7517c306791 Merged revisions 57221-57391 via svnmerge from Guido van Rossum <guido@python.org> parents: 42604 diff changeset	304
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	305 The calculated size of the struct (and hence of the string) corresponding
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 45672 diff changeset	306 to :attr:`format`.
42775 d7517c306791 Merged revisions 57221-57391 via svnmerge from Guido van Rossum <guido@python.org> parents: 42604 diff changeset	307

Mercurial > cpython-lru_cache-weakref

annotate Doc/library/struct.rst @ 58925:eecf1bef052d 2.6