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

annotate Doc/library/difflib.rst @ 58765:2ba7677bfa95 legacy-trunk

testCopysign was defined twice in test_math; combine the definitions

author	Mark Dickinson <dickinsm@gmail.com>
date	Sat, 06 Feb 2010 23:11:25 +0000
parents	2b3945d755a7
children	713f1f6bf339

rev	line source
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	1 :mod:`difflib` --- Helpers for computing deltas
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	2 ===============================================
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 .. module:: difflib
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	5 :synopsis: Helpers for computing differences between objects.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	6 .. moduleauthor:: Tim Peters <tim_one@users.sourceforge.net>
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	7 .. sectionauthor:: Tim Peters <tim_one@users.sourceforge.net>
44383 3625234bf3d2 Some cleanup in the docs. Georg Brandl <georg@python.org> parents: 43753 diff changeset	8 .. Markup by Fred L. Drake, Jr. <fdrake@acm.org>
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	9
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	10 .. testsetup::
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	11
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	12 import sys
31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	13 from difflib import *
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	14
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	15 .. versionadded:: 2.1
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	16
43598 96af41e50e56 Added a cross-ref to each other. Mark Summerfield <list@qtrac.plus.com> parents: 42604 diff changeset	17 This module provides classes and functions for comparing sequences. It
96af41e50e56 Added a cross-ref to each other. Mark Summerfield <list@qtrac.plus.com> parents: 42604 diff changeset	18 can be used for example, for comparing files, and can produce difference
96af41e50e56 Added a cross-ref to each other. Mark Summerfield <list@qtrac.plus.com> parents: 42604 diff changeset	19 information in various formats, including HTML and context and unified
96af41e50e56 Added a cross-ref to each other. Mark Summerfield <list@qtrac.plus.com> parents: 42604 diff changeset	20 diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	21
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	22 .. class:: SequenceMatcher
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	23
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	24 This is a flexible class for comparing pairs of sequences of any type, so long
43753 4b3623568e6c Make "hashable" a glossary entry and clarify docs on __cmp__, __eq__ and __hash__. Georg Brandl <georg@python.org> parents: 43629 diff changeset	25 as the sequence elements are :term:`hashable`. The basic algorithm predates, and is a
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	26 little fancier than, an algorithm published in the late 1980's by Ratcliff and
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	27 Obershelp under the hyperbolic name "gestalt pattern matching." The idea is to
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	28 find the longest contiguous matching subsequence that contains no "junk"
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	29 elements (the Ratcliff and Obershelp algorithm doesn't address junk). The same
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	30 idea is then applied recursively to the pieces of the sequences to the left and
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	31 to the right of the matching subsequence. This does not yield minimal edit
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	32 sequences, but does tend to yield matches that "look right" to people.
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 Timing: The basic Ratcliff-Obershelp algorithm is cubic time in the worst
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	35 case and quadratic time in the expected case. :class:`SequenceMatcher` is
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	36 quadratic time for the worst case and has expected-case behavior dependent in a
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	37 complicated way on how many elements the sequences have in common; best case
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	38 time is linear.
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
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	41 .. class:: Differ
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 This is a class for comparing sequences of lines of text, and producing
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	44 human-readable differences or deltas. Differ uses :class:`SequenceMatcher`
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	45 both to compare sequences of lines, and to compare sequences of characters
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	46 within similar (near-matching) lines.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	47
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	48 Each line of a :class:`Differ` delta begins with a two-letter code:
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 \| Code \| Meaning \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	52 +==========+===========================================+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	53 \| ``'- '`` \| line unique to sequence 1 \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	54 +----------+-------------------------------------------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	55 \| ``'+ '`` \| line unique to sequence 2 \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	56 +----------+-------------------------------------------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	57 \| ``' '`` \| line common to both sequences \|
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	58 +----------+-------------------------------------------+
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	59 \| ``'? '`` \| line not present in either input sequence \|
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
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	62 Lines beginning with '``?``' attempt to guide the eye to intraline differences,
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	63 and were not present in either input sequence. These lines can be confusing if
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	64 the sequences contain tab characters.
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
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	67 .. class:: HtmlDiff
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 This class can be used to create an HTML table (or a complete HTML file
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	70 containing the table) showing a side by side, line by line comparison of text
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	71 with inter-line and intra-line change highlights. The table can be generated in
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	72 either full or contextual difference mode.
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 The constructor for this class is:
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
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	77 .. function:: __init__([tabsize][, wrapcolumn][, linejunk][, charjunk])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	78
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	79 Initializes instance of :class:`HtmlDiff`.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	80
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	81 tabsize is an optional keyword argument to specify tab stop spacing and
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	82 defaults to ``8``.
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 wrapcolumn is an optional keyword to specify column number where lines are
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	85 broken and wrapped, defaults to ``None`` where lines are not wrapped.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	86
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	87 linejunk and charjunk are optional keyword arguments passed into ``ndiff()``
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	88 (used by :class:`HtmlDiff` to generate the side by side HTML differences). See
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	89 ``ndiff()`` documentation for argument default values and descriptions.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	90
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	91 The following methods are public:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	92
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 .. function:: make_file(fromlines, tolines [, fromdesc][, todesc][, context][, numlines])
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 Compares fromlines and tolines (lists of strings) and returns a string which
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	97 is a complete HTML file containing a table showing line by line differences with
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	98 inter-line and intra-line changes highlighted.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	99
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	100 fromdesc and todesc are optional keyword arguments to specify from/to file
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	101 column header strings (both default to an empty string).
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 context and numlines are both optional keyword arguments. Set context to
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	104 ``True`` when contextual differences are to be shown, else the default is
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	105 ``False`` to show the full files. numlines defaults to ``5``. When context
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	106 is ``True`` numlines controls the number of context lines which surround the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	107 difference highlights. When context is ``False`` numlines controls the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	108 number of lines which are shown before a difference highlight when using the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	109 "next" hyperlinks (setting to zero would cause the "next" hyperlinks to place
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	110 the next difference highlight at the top of the browser without any leading
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	111 context).
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	112
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	113
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	114 .. function:: make_table(fromlines, tolines [, fromdesc][, todesc][, context][, numlines])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	115
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	116 Compares fromlines and tolines (lists of strings) and returns a string which
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	117 is a complete HTML table showing line by line differences with inter-line and
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	118 intra-line changes highlighted.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	119
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	120 The arguments for this method are the same as those for the :meth:`make_file`
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	121 method.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	122
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	123 :file:`Tools/scripts/diff.py` is a command-line front-end to this class and
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	124 contains a good example of its use.
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 .. versionadded:: 2.4
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	127
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 .. function:: context_diff(a, b[, fromfile][, tofile][, fromfiledate][, tofiledate][, n][, lineterm])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	130
43629 4f662ba09f1f Add :term: for generators. Georg Brandl <georg@python.org> parents: 43598 diff changeset	131 Compare a and b (lists of strings); return a delta (a :term:`generator`
4f662ba09f1f Add :term: for generators. Georg Brandl <georg@python.org> parents: 43598 diff changeset	132 generating the delta lines) in context diff format.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	133
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	134 Context diffs are a compact way of showing just the lines that have changed plus
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	135 a few lines of context. The changes are shown in a before/after style. The
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	136 number of context lines is set by n which defaults to three.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	137
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	138 By default, the diff control lines (those with ``***`` or ``---``) are created
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	139 with a trailing newline. This is helpful so that inputs created from
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	140 :func:`file.readlines` result in diffs that are suitable for use with
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	141 :func:`file.writelines` since both the inputs and outputs have trailing
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	142 newlines.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	143
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	144 For inputs that do not have trailing newlines, set the lineterm argument to
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	145 ``""`` so that the output will be uniformly newline free.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	146
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	147 The context diff format normally has a header for filenames and modification
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	148 times. Any or all of these may be specified using strings for fromfile,
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	149 tofile, fromfiledate, and tofiledate. The modification times are normally
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	150 expressed in the format returned by :func:`time.ctime`. If not specified, the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	151 strings default to blanks.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	152
45454 d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	153 >>> s1 = ['bacon\n', 'eggs\n', 'ham\n', 'guido\n']
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	154 >>> s2 = ['python\n', 'eggy\n', 'hamster\n', 'guido\n']
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	155 >>> for line in context_diff(s1, s2, fromfile='before.py', tofile='after.py'):
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	156 ... sys.stdout.write(line) # doctest: +NORMALIZE_WHITESPACE
45454 d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	157 *** before.py
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	158 --- after.py
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	159 ***************
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	160 * 1,4 **
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	161 ! bacon
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	162 ! eggs
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	163 ! ham
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	164 guido
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	165 --- 1,4 ----
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	166 ! python
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	167 ! eggy
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	168 ! hamster
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	169 guido
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	170
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	171 See :ref:`difflib-interface` for a more detailed example.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	172
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	173 .. versionadded:: 2.3
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
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	176 .. function:: get_close_matches(word, possibilities[, n][, cutoff])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	177
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	178 Return a list of the best "good enough" matches. word is a sequence for which
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	179 close matches are desired (typically a string), and possibilities is a list of
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	180 sequences against which to match word (typically a list of strings).
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	181
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	182 Optional argument n (default ``3``) is the maximum number of close matches to
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	183 return; n must be greater than ``0``.
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 Optional argument cutoff (default ``0.6``) is a float in the range [0, 1].
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	186 Possibilities that don't score at least that similar to word are ignored.
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 The best (no more than n) matches among the possibilities are returned in a
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	189 list, sorted by similarity score, most similar first.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	190
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	191 >>> get_close_matches('appel', ['ape', 'apple', 'peach', 'puppy'])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	192 ['apple', 'ape']
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	193 >>> import keyword
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	194 >>> get_close_matches('wheel', keyword.kwlist)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	195 ['while']
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	196 >>> get_close_matches('apple', keyword.kwlist)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	197 []
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	198 >>> get_close_matches('accept', keyword.kwlist)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	199 ['except']
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	200
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	201
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	202 .. function:: ndiff(a, b[, linejunk][, charjunk])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	203
43629 4f662ba09f1f Add :term: for generators. Georg Brandl <georg@python.org> parents: 43598 diff changeset	204 Compare a and b (lists of strings); return a :class:`Differ`\ -style
4f662ba09f1f Add :term: for generators. Georg Brandl <georg@python.org> parents: 43598 diff changeset	205 delta (a :term:`generator` generating the delta lines).
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	206
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	207 Optional keyword parameters linejunk and charjunk are for filter functions
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	208 (or ``None``):
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	209
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	210 linejunk: A function that accepts a single string argument, and returns true
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	211 if the string is junk, or false if not. The default is (``None``), starting with
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	212 Python 2.3. Before then, the default was the module-level function
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	213 :func:`IS_LINE_JUNK`, which filters out lines without visible characters, except
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	214 for at most one pound character (``'#'``). As of Python 2.3, the underlying
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	215 :class:`SequenceMatcher` class does a dynamic analysis of which lines are so
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	216 frequent as to constitute noise, and this usually works better than the pre-2.3
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	217 default.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	218
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	219 charjunk: A function that accepts a character (a string of length 1), and
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	220 returns if the character is junk, or false if not. The default is module-level
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	221 function :func:`IS_CHARACTER_JUNK`, which filters out whitespace characters (a
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	222 blank or tab; note: bad idea to include newline in this!).
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	223
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	224 :file:`Tools/scripts/ndiff.py` is a command-line front-end to this function.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	225
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	226 >>> diff = ndiff('one\ntwo\nthree\n'.splitlines(1),
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	227 ... 'ore\ntree\nemu\n'.splitlines(1))
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	228 >>> print ''.join(diff),
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	229 - one
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	230 ? ^
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	231 + ore
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	232 ? ^
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	233 - two
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	234 - three
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	235 ? -
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	236 + tree
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	237 + emu
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	238
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	239
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	240 .. function:: restore(sequence, which)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	241
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	242 Return one of the two sequences that generated a delta.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	243
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	244 Given a sequence produced by :meth:`Differ.compare` or :func:`ndiff`, extract
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	245 lines originating from file 1 or 2 (parameter which), stripping off line
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	246 prefixes.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	247
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	248 Example:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	249
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	250 >>> diff = ndiff('one\ntwo\nthree\n'.splitlines(1),
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	251 ... 'ore\ntree\nemu\n'.splitlines(1))
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	252 >>> diff = list(diff) # materialize the generated delta into a list
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	253 >>> print ''.join(restore(diff, 1)),
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	254 one
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	255 two
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	256 three
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	257 >>> print ''.join(restore(diff, 2)),
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	258 ore
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	259 tree
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	260 emu
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	261
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 .. function:: unified_diff(a, b[, fromfile][, tofile][, fromfiledate][, tofiledate][, n][, lineterm])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	264
43629 4f662ba09f1f Add :term: for generators. Georg Brandl <georg@python.org> parents: 43598 diff changeset	265 Compare a and b (lists of strings); return a delta (a :term:`generator`
4f662ba09f1f Add :term: for generators. Georg Brandl <georg@python.org> parents: 43598 diff changeset	266 generating the delta lines) in unified diff format.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	267
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	268 Unified diffs are a compact way of showing just the lines that have changed plus
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	269 a few lines of context. The changes are shown in a inline style (instead of
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	270 separate before/after blocks). The number of context lines is set by n which
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	271 defaults to three.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	272
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	273 By default, the diff control lines (those with ``---``, ``+++``, or ``@@``) are
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	274 created with a trailing newline. This is helpful so that inputs created from
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	275 :func:`file.readlines` result in diffs that are suitable for use with
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	276 :func:`file.writelines` since both the inputs and outputs have trailing
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	277 newlines.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	278
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	279 For inputs that do not have trailing newlines, set the lineterm argument to
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	280 ``""`` so that the output will be uniformly newline free.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	281
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	282 The context diff format normally has a header for filenames and modification
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	283 times. Any or all of these may be specified using strings for fromfile,
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	284 tofile, fromfiledate, and tofiledate. The modification times are normally
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	285 expressed in the format returned by :func:`time.ctime`. If not specified, the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	286 strings default to blanks.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	287
45454 d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	288 >>> s1 = ['bacon\n', 'eggs\n', 'ham\n', 'guido\n']
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	289 >>> s2 = ['python\n', 'eggy\n', 'hamster\n', 'guido\n']
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	290 >>> for line in unified_diff(s1, s2, fromfile='before.py', tofile='after.py'):
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	291 ... sys.stdout.write(line) # doctest: +NORMALIZE_WHITESPACE
45454 d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	292 --- before.py
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	293 +++ after.py
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	294 @@ -1,4 +1,4 @@
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	295 -bacon
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	296 -eggs
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	297 -ham
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	298 +python
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	299 +eggy
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	300 +hamster
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	301 guido
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	302
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	303 See :ref:`difflib-interface` for a more detailed example.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	304
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	305 .. versionadded:: 2.3
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	306
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	307
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	308 .. function:: IS_LINE_JUNK(line)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	309
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	310 Return true for ignorable lines. The line line is ignorable if line is
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	311 blank or contains a single ``'#'``, otherwise it is not ignorable. Used as a
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	312 default for parameter linejunk in :func:`ndiff` before Python 2.3.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	313
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	314
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	315 .. function:: IS_CHARACTER_JUNK(ch)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	316
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	317 Return true for ignorable characters. The character ch is ignorable if ch
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	318 is a space or tab, otherwise it is not ignorable. Used as a default for
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	319 parameter charjunk in :func:`ndiff`.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	320
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	321
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	322 .. seealso::
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	323
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	324 `Pattern Matching: The Gestalt Approach <http://www.ddj.com/184407970?pgno=5>`_
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	325 Discussion of a similar algorithm by John W. Ratcliff and D. E. Metzener. This
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	326 was published in `Dr. Dobb's Journal <http://www.ddj.com/>`_ in July, 1988.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	327
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	328
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	329 .. _sequence-matcher:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	330
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	331 SequenceMatcher Objects
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	332 -----------------------
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	333
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	334 The :class:`SequenceMatcher` class has this constructor:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	335
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	336
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	337 .. class:: SequenceMatcher([isjunk[, a[, b]]])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	338
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	339 Optional argument isjunk must be ``None`` (the default) or a one-argument
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	340 function that takes a sequence element and returns true if and only if the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	341 element is "junk" and should be ignored. Passing ``None`` for isjunk is
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	342 equivalent to passing ``lambda x: 0``; in other words, no elements are ignored.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	343 For example, pass::
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	344
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	345 lambda x: x in " \t"
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	346
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	347 if you're comparing lines as sequences of characters, and don't want to synch up
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	348 on blanks or hard tabs.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	349
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	350 The optional arguments a and b are sequences to be compared; both default to
43753 4b3623568e6c Make "hashable" a glossary entry and clarify docs on __cmp__, __eq__ and __hash__. Georg Brandl <georg@python.org> parents: 43629 diff changeset	351 empty strings. The elements of both sequences must be :term:`hashable`.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	352
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	353 :class:`SequenceMatcher` objects have the following methods:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	354
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	355
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	356 .. method:: set_seqs(a, b)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	357
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	358 Set the two sequences to be compared.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	359
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	360 :class:`SequenceMatcher` computes and caches detailed information about the
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	361 second sequence, so if you want to compare one sequence against many
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	362 sequences, use :meth:`set_seq2` to set the commonly used sequence once and
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	363 call :meth:`set_seq1` repeatedly, once for each of the other sequences.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	364
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	365
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	366 .. method:: set_seq1(a)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	367
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	368 Set the first sequence to be compared. The second sequence to be compared
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	369 is not changed.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	370
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	371
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	372 .. method:: set_seq2(b)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	373
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	374 Set the second sequence to be compared. The first sequence to be compared
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	375 is not changed.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	376
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	377
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	378 .. method:: find_longest_match(alo, ahi, blo, bhi)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	379
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	380 Find longest matching block in ``a[alo:ahi]`` and ``b[blo:bhi]``.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	381
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	382 If isjunk was omitted or ``None``, :meth:`find_longest_match` returns
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	383 ``(i, j, k)`` such that ``a[i:i+k]`` is equal to ``b[j:j+k]``, where ``alo
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	384 <= i <= i+k <= ahi`` and ``blo <= j <= j+k <= bhi``. For all ``(i', j',
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	385 k')`` meeting those conditions, the additional conditions ``k >= k'``, ``i
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	386 <= i'``, and if ``i == i'``, ``j <= j'`` are also met. In other words, of
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	387 all maximal matching blocks, return one that starts earliest in a, and
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	388 of all those maximal matching blocks that start earliest in a, return
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	389 the one that starts earliest in b.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	390
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	391 >>> s = SequenceMatcher(None, " abcd", "abcd abcd")
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	392 >>> s.find_longest_match(0, 5, 0, 9)
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	393 Match(a=0, b=4, size=5)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	394
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	395 If isjunk was provided, first the longest matching block is determined
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	396 as above, but with the additional restriction that no junk element appears
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	397 in the block. Then that block is extended as far as possible by matching
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	398 (only) junk elements on both sides. So the resulting block never matches
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	399 on junk except as identical junk happens to be adjacent to an interesting
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	400 match.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	401
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	402 Here's the same example as before, but considering blanks to be junk. That
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	403 prevents ``' abcd'`` from matching the ``' abcd'`` at the tail end of the
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	404 second sequence directly. Instead only the ``'abcd'`` can match, and
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	405 matches the leftmost ``'abcd'`` in the second sequence:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	406
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	407 >>> s = SequenceMatcher(lambda x: x==" ", " abcd", "abcd abcd")
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	408 >>> s.find_longest_match(0, 5, 0, 9)
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	409 Match(a=1, b=0, size=4)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	410
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	411 If no blocks match, this returns ``(alo, blo, 0)``.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	412
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	413 .. versionchanged:: 2.6
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	414 This method returns a :term:`named tuple` ``Match(a, b, size)``.
44638 62f6d780a11d Documentation for r5990[3567]. Georg Brandl <georg@python.org> parents: 44383 diff changeset	415
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	416
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	417 .. method:: get_matching_blocks()
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	418
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	419 Return list of triples describing matching subsequences. Each triple is of
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	420 the form ``(i, j, n)``, and means that ``a[i:i+n] == b[j:j+n]``. The
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	421 triples are monotonically increasing in i and j.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	422
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	423 The last triple is a dummy, and has the value ``(len(a), len(b), 0)``. It
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	424 is the only triple with ``n == 0``. If ``(i, j, n)`` and ``(i', j', n')``
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	425 are adjacent triples in the list, and the second is not the last triple in
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	426 the list, then ``i+n != i'`` or ``j+n != j'``; in other words, adjacent
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	427 triples always describe non-adjacent equal blocks.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	428
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	429 .. XXX Explain why a dummy is used!
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	430
50522 ee9ced92843a Merged revisions 68133-68134,68141-68142,68145-68146,68148-68149,68159-68162,68166,68171-68174,68179,68195-68196,68210,68214-68215,68217-68222 via svnmerge from Georg Brandl <georg@python.org> parents: 46555 diff changeset	431 .. versionchanged:: 2.5
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	432 The guarantee that adjacent triples always describe non-adjacent blocks
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	433 was implemented.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	434
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	435 .. doctest::
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	436
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	437 >>> s = SequenceMatcher(None, "abxcd", "abcd")
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	438 >>> s.get_matching_blocks()
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	439 [Match(a=0, b=0, size=2), Match(a=3, b=2, size=2), Match(a=5, b=4, size=0)]
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	440
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	441
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	442 .. method:: get_opcodes()
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	443
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	444 Return list of 5-tuples describing how to turn a into b. Each tuple is
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	445 of the form ``(tag, i1, i2, j1, j2)``. The first tuple has ``i1 == j1 ==
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	446 0``, and remaining tuples have i1 equal to the i2 from the preceding
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	447 tuple, and, likewise, j1 equal to the previous j2.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	448
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	449 The tag values are strings, with these meanings:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	450
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	451 +---------------+---------------------------------------------+
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	452 \| Value \| Meaning \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	453 +===============+=============================================+
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	454 \| ``'replace'`` \| ``a[i1:i2]`` should be replaced by \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	455 \| \| ``b[j1:j2]``. \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	456 +---------------+---------------------------------------------+
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	457 \| ``'delete'`` \| ``a[i1:i2]`` should be deleted. Note that \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	458 \| \| ``j1 == j2`` in this case. \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	459 +---------------+---------------------------------------------+
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	460 \| ``'insert'`` \| ``b[j1:j2]`` should be inserted at \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	461 \| \| ``a[i1:i1]``. Note that ``i1 == i2`` in \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	462 \| \| this case. \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	463 +---------------+---------------------------------------------+
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	464 \| ``'equal'`` \| ``a[i1:i2] == b[j1:j2]`` (the sub-sequences \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	465 \| \| are equal). \|
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	466 +---------------+---------------------------------------------+
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	467
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	468 For example:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	469
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	470 >>> a = "qabxcd"
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	471 >>> b = "abycdf"
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	472 >>> s = SequenceMatcher(None, a, b)
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	473 >>> for tag, i1, i2, j1, j2 in s.get_opcodes():
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	474 ... print ("%7s a[%d:%d] (%s) b[%d:%d] (%s)" %
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	475 ... (tag, i1, i2, a[i1:i2], j1, j2, b[j1:j2]))
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	476 delete a[0:1] (q) b[0:0] ()
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	477 equal a[1:3] (ab) b[0:2] (ab)
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	478 replace a[3:4] (x) b[2:3] (y)
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	479 equal a[4:6] (cd) b[3:5] (cd)
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	480 insert a[6:6] () b[5:6] (f)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	481
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	482
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	483 .. method:: get_grouped_opcodes([n])
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	484
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	485 Return a :term:`generator` of groups with up to n lines of context.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	486
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	487 Starting with the groups returned by :meth:`get_opcodes`, this method
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	488 splits out smaller change clusters and eliminates intervening ranges which
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	489 have no changes.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	490
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	491 The groups are returned in the same format as :meth:`get_opcodes`.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	492
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	493 .. versionadded:: 2.3
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	494
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	495
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	496 .. method:: ratio()
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	497
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	498 Return a measure of the sequences' similarity as a float in the range [0,
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	499 1].
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	500
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	501 Where T is the total number of elements in both sequences, and M is the
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	502 number of matches, this is 2.0\*M / T. Note that this is ``1.0`` if the
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	503 sequences are identical, and ``0.0`` if they have nothing in common.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	504
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	505 This is expensive to compute if :meth:`get_matching_blocks` or
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	506 :meth:`get_opcodes` hasn't already been called, in which case you may want
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	507 to try :meth:`quick_ratio` or :meth:`real_quick_ratio` first to get an
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	508 upper bound.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	509
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	510
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	511 .. method:: quick_ratio()
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	512
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	513 Return an upper bound on :meth:`ratio` relatively quickly.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	514
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	515 This isn't defined beyond that it is an upper bound on :meth:`ratio`, and
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	516 is faster to compute.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	517
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	518
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	519 .. method:: real_quick_ratio()
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	520
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	521 Return an upper bound on :meth:`ratio` very quickly.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	522
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	523 This isn't defined beyond that it is an upper bound on :meth:`ratio`, and
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	524 is faster to compute than either :meth:`ratio` or :meth:`quick_ratio`.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	525
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	526 The three methods that return the ratio of matching to total characters can give
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	527 different results due to differing levels of approximation, although
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	528 :meth:`quick_ratio` and :meth:`real_quick_ratio` are always at least as large as
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	529 :meth:`ratio`:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	530
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	531 >>> s = SequenceMatcher(None, "abcd", "bcde")
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	532 >>> s.ratio()
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	533 0.75
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	534 >>> s.quick_ratio()
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	535 0.75
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	536 >>> s.real_quick_ratio()
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	537 1.0
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	538
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	539
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	540 .. _sequencematcher-examples:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	541
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	542 SequenceMatcher Examples
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	543 ------------------------
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	544
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	545 This example compares two strings, considering blanks to be "junk:"
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	546
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	547 >>> s = SequenceMatcher(lambda x: x == " ",
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	548 ... "private Thread currentThread;",
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	549 ... "private volatile Thread currentThread;")
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	550
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	551 :meth:`ratio` returns a float in [0, 1], measuring the similarity of the
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	552 sequences. As a rule of thumb, a :meth:`ratio` value over 0.6 means the
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	553 sequences are close matches:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	554
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	555 >>> print round(s.ratio(), 3)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	556 0.866
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	557
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	558 If you're only interested in where the sequences match,
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	559 :meth:`get_matching_blocks` is handy:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	560
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	561 >>> for block in s.get_matching_blocks():
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	562 ... print "a[%d] and b[%d] match for %d elements" % block
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	563 a[0] and b[0] match for 8 elements
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	564 a[8] and b[17] match for 21 elements
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	565 a[29] and b[38] match for 0 elements
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	566
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	567 Note that the last tuple returned by :meth:`get_matching_blocks` is always a
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	568 dummy, ``(len(a), len(b), 0)``, and this is the only case in which the last
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	569 tuple element (number of elements matched) is ``0``.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	570
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	571 If you want to know how to change the first sequence into the second, use
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	572 :meth:`get_opcodes`:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	573
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	574 >>> for opcode in s.get_opcodes():
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	575 ... print "%6s a[%d:%d] b[%d:%d]" % opcode
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	576 equal a[0:8] b[0:8]
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	577 insert a[8:8] b[8:17]
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	578 equal a[8:29] b[17:38]
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	579
53552 2b3945d755a7 Add example to the seealso section. Raymond Hettinger <python@rcn.com> parents: 51745 diff changeset	580 .. seealso::
2b3945d755a7 Add example to the seealso section. Raymond Hettinger <python@rcn.com> parents: 51745 diff changeset	581
2b3945d755a7 Add example to the seealso section. Raymond Hettinger <python@rcn.com> parents: 51745 diff changeset	582 * The :func:`get_close_matches` function in this module which shows how
2b3945d755a7 Add example to the seealso section. Raymond Hettinger <python@rcn.com> parents: 51745 diff changeset	583 simple code building on :class:`SequenceMatcher` can be used to do useful
2b3945d755a7 Add example to the seealso section. Raymond Hettinger <python@rcn.com> parents: 51745 diff changeset	584 work.
2b3945d755a7 Add example to the seealso section. Raymond Hettinger <python@rcn.com> parents: 51745 diff changeset	585
2b3945d755a7 Add example to the seealso section. Raymond Hettinger <python@rcn.com> parents: 51745 diff changeset	586 * `Simple version control recipe
2b3945d755a7 Add example to the seealso section. Raymond Hettinger <python@rcn.com> parents: 51745 diff changeset	587 <http://code.activestate.com/recipes/576729/>`_ for a small application
2b3945d755a7 Add example to the seealso section. Raymond Hettinger <python@rcn.com> parents: 51745 diff changeset	588 built with :class:`SequenceMatcher`.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	589
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	590
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	591 .. _differ-objects:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	592
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	593 Differ Objects
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	594 --------------
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	595
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	596 Note that :class:`Differ`\ -generated deltas make no claim to be minimal
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	597 diffs. To the contrary, minimal diffs are often counter-intuitive, because they
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	598 synch up anywhere possible, sometimes accidental matches 100 pages apart.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	599 Restricting synch points to contiguous matches preserves some notion of
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	600 locality, at the occasional cost of producing a longer diff.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	601
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	602 The :class:`Differ` class has this constructor:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	603
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	604
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	605 .. class:: Differ([linejunk[, charjunk]])
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	606
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	607 Optional keyword parameters linejunk and charjunk are for filter functions
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	608 (or ``None``):
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	609
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	610 linejunk: A function that accepts a single string argument, and returns true
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	611 if the string is junk. The default is ``None``, meaning that no line is
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	612 considered junk.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	613
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	614 charjunk: A function that accepts a single character argument (a string of
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	615 length 1), and returns true if the character is junk. The default is ``None``,
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	616 meaning that no character is considered junk.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	617
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	618 :class:`Differ` objects are used (deltas generated) via a single method:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	619
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	620
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	621 .. method:: Differ.compare(a, b)
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	622
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	623 Compare two sequences of lines, and generate the delta (a sequence of lines).
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	624
46555 66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	625 Each sequence must contain individual single-line strings ending with newlines.
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	626 Such sequences can be obtained from the :meth:`readlines` method of file-like
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	627 objects. The delta generated also consists of newline-terminated strings, ready
66c8bd1bedf3 reformat some documentation of classes so methods and attributes are under the class directive Benjamin Peterson <benjamin@python.org> parents: 46014 diff changeset	628 to be printed as-is via the :meth:`writelines` method of a file-like object.
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	629
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	630
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	631 .. _differ-examples:
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	632
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	633 Differ Example
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	634 --------------
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	635
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	636 This example compares two texts. First we set up the texts, sequences of
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	637 individual single-line strings ending with newlines (such sequences can also be
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	638 obtained from the :meth:`readlines` method of file-like objects):
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	639
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	640 >>> text1 = ''' 1. Beautiful is better than ugly.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	641 ... 2. Explicit is better than implicit.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	642 ... 3. Simple is better than complex.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	643 ... 4. Complex is better than complicated.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	644 ... '''.splitlines(1)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	645 >>> len(text1)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	646 4
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	647 >>> text1[0][-1]
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	648 '\n'
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	649 >>> text2 = ''' 1. Beautiful is better than ugly.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	650 ... 3. Simple is better than complex.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	651 ... 4. Complicated is better than complex.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	652 ... 5. Flat is better than nested.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	653 ... '''.splitlines(1)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	654
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	655 Next we instantiate a Differ object:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	656
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	657 >>> d = Differ()
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	658
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	659 Note that when instantiating a :class:`Differ` object we may pass functions to
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	660 filter out line and character "junk." See the :meth:`Differ` constructor for
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	661 details.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	662
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	663 Finally, we compare the two:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	664
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	665 >>> result = list(d.compare(text1, text2))
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	666
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	667 ``result`` is a list of strings, so let's pretty-print it:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	668
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	669 >>> from pprint import pprint
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	670 >>> pprint(result)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	671 [' 1. Beautiful is better than ugly.\n',
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	672 '- 2. Explicit is better than implicit.\n',
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	673 '- 3. Simple is better than complex.\n',
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	674 '+ 3. Simple is better than complex.\n',
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	675 '? ++\n',
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	676 '- 4. Complex is better than complicated.\n',
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	677 '? ^ ---- ^\n',
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	678 '+ 4. Complicated is better than complex.\n',
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	679 '? ++++ ^ ^\n',
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	680 '+ 5. Flat is better than nested.\n']
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	681
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	682 As a single multi-line string it looks like this:
42604 9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	683
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	684 >>> import sys
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	685 >>> sys.stdout.writelines(result)
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	686 1. Beautiful is better than ugly.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	687 - 2. Explicit is better than implicit.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	688 - 3. Simple is better than complex.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	689 + 3. Simple is better than complex.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	690 ? ++
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	691 - 4. Complex is better than complicated.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	692 ? ^ ---- ^
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	693 + 4. Complicated is better than complex.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	694 ? ++++ ^ ^
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	695 + 5. Flat is better than nested.
9e1529bf0442 Move the 3k reST doc tree in place. Georg Brandl <georg@python.org> parents: diff changeset	696
45454 d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	697
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	698 .. _difflib-interface:
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	699
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	700 A command-line interface to difflib
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	701 -----------------------------------
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	702
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	703 This example shows how to use difflib to create a ``diff``-like utility.
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	704 It is also contained in the Python source distribution, as
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	705 :file:`Tools/scripts/diff.py`.
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	706
46014 31cf38bdaac0 Enable doctest running for several other documents. Georg Brandl <georg@python.org> parents: 45454 diff changeset	707 .. testcode::
45454 d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	708
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	709 """ Command line interface to difflib.py providing diffs in four formats:
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	710
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	711 * ndiff: lists every line and highlights interline changes.
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	712 * context: highlights clusters of changes in a before/after format.
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	713 * unified: highlights clusters of changes in an inline format.
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	714 * html: generates side by side comparison with change highlights.
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	715
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	716 """
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	717
51745 9815da43a1ce revert r69777 since all the experts agree that extra import lines distract from the code Benjamin Peterson <benjamin@python.org> parents: 51742 diff changeset	718 import sys, os, time, difflib, optparse
45454 d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	719
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	720 def main():
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	721 # Configure the option parser
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	722 usage = "usage: %prog [options] fromfile tofile"
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	723 parser = optparse.OptionParser(usage)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	724 parser.add_option("-c", action="store_true", default=False,
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	725 help='Produce a context format diff (default)')
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	726 parser.add_option("-u", action="store_true", default=False,
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	727 help='Produce a unified format diff')
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	728 hlp = 'Produce HTML side by side diff (can use -c and -l in conjunction)'
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	729 parser.add_option("-m", action="store_true", default=False, help=hlp)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	730 parser.add_option("-n", action="store_true", default=False,
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	731 help='Produce a ndiff format diff')
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	732 parser.add_option("-l", "--lines", type="int", default=3,
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	733 help='Set number of context lines (default 3)')
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	734 (options, args) = parser.parse_args()
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	735
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	736 if len(args) == 0:
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	737 parser.print_help()
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	738 sys.exit(1)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	739 if len(args) != 2:
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	740 parser.error("need to specify both a fromfile and tofile")
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	741
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	742 n = options.lines
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	743 fromfile, tofile = args # as specified in the usage string
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	744
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	745 # we're passing these as arguments to the diff function
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	746 fromdate = time.ctime(os.stat(fromfile).st_mtime)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	747 todate = time.ctime(os.stat(tofile).st_mtime)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	748 fromlines = open(fromfile, 'U').readlines()
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	749 tolines = open(tofile, 'U').readlines()
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	750
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	751 if options.u:
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	752 diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile,
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	753 fromdate, todate, n=n)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	754 elif options.n:
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	755 diff = difflib.ndiff(fromlines, tolines)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	756 elif options.m:
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	757 diff = difflib.HtmlDiff().make_file(fromlines, tolines, fromfile,
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	758 tofile, context=options.c,
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	759 numlines=n)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	760 else:
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	761 diff = difflib.context_diff(fromlines, tolines, fromfile, tofile,
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	762 fromdate, todate, n=n)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	763
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	764 # we're using writelines because diff is a generator
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	765 sys.stdout.writelines(diff)
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	766
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	767 if __name__ == '__main__':
d7e232e9f1a1 More difflib examples. Written for GHOP by Josip Dzolonga. Georg Brandl <georg@python.org> parents: 44638 diff changeset	768 main()

Mercurial > cpython-lru_cache-weakref

annotate Doc/library/difflib.rst @ 58765:2ba7677bfa95 legacy-trunk