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

annotate Doc/lib/libdifflib.tex @ 33462:5876636ca8c6 legacy-trunk

HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace.

author	Tim Peters <tim.peters@gmail.com>
date	Sun, 12 Sep 2004 03:21:00 +0000
parents	5570fae1f01c
children	10b25414628c

rev	line source
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	1 \section{\module{difflib} ---
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	2 Helpers for computing deltas}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	3
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	4 \declaremodule{standard}{difflib}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	5 \modulesynopsis{Helpers for computing differences between objects.}
31275 8c13ab69ba4f - update Tim's email address Fred Drake <fdrake@acm.org> parents: 29404 diff changeset	6 \moduleauthor{Tim Peters}{tim_one@users.sourceforge.net}
8c13ab69ba4f - update Tim's email address Fred Drake <fdrake@acm.org> parents: 29404 diff changeset	7 \sectionauthor{Tim Peters}{tim_one@users.sourceforge.net}
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	8 % LaTeXification by Fred L. Drake, Jr. <fdrake@acm.org>.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	9
17388 e4abe74bc973 Add note that difflib was added in Python 2.1. Fred Drake <fdrake@acm.org> parents: 17382 diff changeset	10 \versionadded{2.1}
e4abe74bc973 Add note that difflib was added in Python 2.1. Fred Drake <fdrake@acm.org> parents: 17382 diff changeset	11
e4abe74bc973 Add note that difflib was added in Python 2.1. Fred Drake <fdrake@acm.org> parents: 17382 diff changeset	12
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	13 \begin{classdesc*}{SequenceMatcher}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	14 This is a flexible class for comparing pairs of sequences of any
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	15 type, so long as the sequence elements are hashable. The basic
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	16 algorithm predates, and is a little fancier than, an algorithm
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	17 published in the late 1980's by Ratcliff and Obershelp under the
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	18 hyperbolic name ``gestalt pattern matching.'' The idea is to find
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	19 the longest contiguous matching subsequence that contains no
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	20 ``junk'' elements (the Ratcliff and Obershelp algorithm doesn't
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	21 address junk). The same idea is then applied recursively to the
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	22 pieces of the sequences to the left and to the right of the matching
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	23 subsequence. This does not yield minimal edit sequences, but does
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	24 tend to yield matches that ``look right'' to people.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	25
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	26 \strong{Timing:} The basic Ratcliff-Obershelp algorithm is cubic
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	27 time in the worst case and quadratic time in the expected case.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	28 \class{SequenceMatcher} is quadratic time for the worst case and has
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	29 expected-case behavior dependent in a complicated way on how many
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	30 elements the sequences have in common; best case time is linear.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	31 \end{classdesc*}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	32
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	33 \begin{classdesc*}{Differ}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	34 This is a class for comparing sequences of lines of text, and
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	35 producing human-readable differences or deltas. Differ uses
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	36 \class{SequenceMatcher} both to compare sequences of lines, and to
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	37 compare sequences of characters within similar (near-matching)
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	38 lines.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	39
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	40 Each line of a \class{Differ} delta begins with a two-letter code:
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	41
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	42 \begin{tableii}{l\|l}{code}{Code}{Meaning}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	43 \lineii{'- '}{line unique to sequence 1}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	44 \lineii{'+ '}{line unique to sequence 2}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	45 \lineii{' '}{line common to both sequences}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	46 \lineii{'? '}{line not present in either input sequence}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	47 \end{tableii}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	48
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	49 Lines beginning with `\code{?~}' attempt to guide the eye to
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	50 intraline differences, and were not present in either input
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	51 sequence. These lines can be confusing if the sequences contain tab
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	52 characters.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	53 \end{classdesc*}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	54
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	55 \begin{classdesc*}{HtmlDiff}
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	56
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	57 This class can be used to create an HTML table (or a complete HTML file
33448 5570fae1f01c Typo fix: 'comparisions' is not a word Andrew M. Kuchling <amk@amk.ca> parents: 33319 diff changeset	58 containing the table) showing a side by side, line by line comparison
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	59 of text with inter-line and intra-line change highlights. The table can
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	60 be generated in either full or contextual difference mode.
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	61
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	62 The constructor for this class is:
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	63
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	64 \begin{funcdesc}{__init__}{
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	65 \optional{, tabsize
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	66 \optional{, wrapcolumn
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	67 \optional{, linejunk
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	68 \optional{, charjunk}}}}}
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	69
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	70 Initializes instance of \class{HtmlDiff}.
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	71
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	72 \var{tabsize} is an optional keyword argument to specify tab stop spacing
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	73 and defaults to \code{8}.
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	74
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	75 \var{wrapcolumn} is an optional keyword to specify column number where
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	76 lines are broken and wrapped, defaults to \code{None} where lines are not
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	77 wrapped.
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	78
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	79 \var{linejunk} and \var{charjunk} are optional keyword arguments passed
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	80 into \code{ndiff()} (used by \class{HtmlDiff} to generate the
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	81 side by side HTML differences). See \code{ndiff()} documentation for
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	82 argument default values and descriptions.
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	83
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	84 \end{funcdesc}
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	85
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	86 The following methods are public:
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	87
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	88 \begin{funcdesc}{make_file}{fromlines, tolines
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	89 \optional{, fromdesc
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	90 \optional{, todesc
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	91 \optional{, context
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	92 \optional{, numlines}}}}}
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	93 Compares \var{fromlines} and \var{tolines} (lists of strings) and returns
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	94 a string which is a complete HTML file containing a table showing line by
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	95 line differences with inter-line and intra-line changes highlighted.
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	96
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	97 \var{fromdesc} and \var{todesc} are optional keyword arguments to specify
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	98 from/to file column header strings (both default to an empty string).
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	99
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	100 \var{context} and \var{numlines} are both optional keyword arguments.
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	101 Set \var{context} to \code{True} when contextual differences are to be
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	102 shown, else the default is \code{False} to show the full files.
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	103 \var{numlines} defaults to \code{5}. When \var{context} is \code{True}
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	104 \var{numlines} controls the number of context lines which surround the
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	105 difference highlights. When \var{context} is \code{False} \var{numlines}
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	106 controls the number of lines which are shown before a difference
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	107 highlight when using the "next" hyperlinks (setting to zero would cause
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	108 the "next" hyperlinks to place the next difference highlight at the top of
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	109 the browser without any leading context).
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	110 \end{funcdesc}
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	111
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	112 \begin{funcdesc}{make_table}{fromlines, tolines
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	113 \optional{, fromdesc
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	114 \optional{, todesc
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	115 \optional{, context}}}}
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	116 Compares \var{fromlines} and \var{tolines} (lists of strings) and returns
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	117 a string which is a complete HTML table showing line by line differences
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	118 with inter-line and intra-line changes highlighted.
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	119
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	120 The arguments of this method are a subset of those for the
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	121 \code{make_file} method. Refer to the \code{make_file} method
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	122 documentation.
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	123 \end{funcdesc}
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	124
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	125 \file{Tools/scripts/diff.py} is a command-line front-end to this class
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	126 and contains a good example of its use.
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	127
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	128 \versionadded{2.4}
33319 6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	129 \end{classdesc*}
6d3bdd19beeb Patch #914575: difflib side by side diff support, diff.py s/b/s HTML option. Martin v. Löwis <martin@v.loewis.de> parents: 31410 diff changeset	130
29398 e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	131 \begin{funcdesc}{context_diff}{a, b\optional{, fromfile\optional{, tofile
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	132 \optional{, fromfiledate\optional{, tofiledate\optional{, n
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	133 \optional{, lineterm}}}}}}}
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	134 Compare \var{a} and \var{b} (lists of strings); return a
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	135 delta (a generator generating the delta lines) in context diff
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	136 format.
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	137
29398 e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	138 Context diffs are a compact way of showing just the lines that have
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	139 changed plus a few lines of context. The changes are shown in a
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	140 before/after style. The number of context lines is set by \var{n}
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	141 which defaults to three.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	142
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	143 By default, the diff control lines (those with \code{***} or \code{---})
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	144 are created with a trailing newline. This is helpful so that inputs created
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	145 from \function{file.readlines()} result in diffs that are suitable for use
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	146 with \function{file.writelines()} since both the inputs and outputs have
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	147 trailing newlines.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	148
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	149 For inputs that do not have trailing newlines, set the \var{lineterm}
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	150 argument to \code{""} so that the output will be uniformly newline free.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	151
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	152 The context diff format normally has a header for filenames and
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	153 modification times. Any or all of these may be specified using strings for
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	154 \var{fromfile}, \var{tofile}, \var{fromfiledate}, and \var{tofiledate}.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	155 The modification times are normally expressed in the format returned by
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	156 \function{time.ctime()}. If not specified, the strings default to blanks.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	157
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	158 \file{Tools/scripts/diff.py} is a command-line front-end for this
29404 8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	159 function.
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	160
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	161 \versionadded{2.3}
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	162 \end{funcdesc}
29398 e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	163
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	164 \begin{funcdesc}{get_close_matches}{word, possibilities\optional{,
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	165 n\optional{, cutoff}}}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	166 Return a list of the best ``good enough'' matches. \var{word} is a
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	167 sequence for which close matches are desired (typically a string),
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	168 and \var{possibilities} is a list of sequences against which to
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	169 match \var{word} (typically a list of strings).
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	170
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	171 Optional argument \var{n} (default \code{3}) is the maximum number
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	172 of close matches to return; \var{n} must be greater than \code{0}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	173
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	174 Optional argument \var{cutoff} (default \code{0.6}) is a float in
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	175 the range [0, 1]. Possibilities that don't score at least that
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	176 similar to \var{word} are ignored.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	177
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	178 The best (no more than \var{n}) matches among the possibilities are
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	179 returned in a list, sorted by similarity score, most similar first.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	180
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	181 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	182 >>> get_close_matches('appel', ['ape', 'apple', 'peach', 'puppy'])
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	183 ['apple', 'ape']
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	184 >>> import keyword
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	185 >>> get_close_matches('wheel', keyword.kwlist)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	186 ['while']
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	187 >>> get_close_matches('apple', keyword.kwlist)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	188 []
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	189 >>> get_close_matches('accept', keyword.kwlist)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	190 ['except']
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	191 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	192 \end{funcdesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	193
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	194 \begin{funcdesc}{ndiff}{a, b\optional{, linejunk\optional{,
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	195 charjunk}}}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	196 Compare \var{a} and \var{b} (lists of strings); return a
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	197 \class{Differ}-style delta (a generator generating the delta lines).
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	198
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	199 Optional keyword parameters \var{linejunk} and \var{charjunk} are
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	200 for filter functions (or \code{None}):
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	201
23300 b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	202 \var{linejunk}: A function that accepts a single string
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	203 argument, and returns true if the string is junk, or false if not.
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	204 The default is (\code{None}), starting with Python 2.3. Before then,
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	205 the default was the module-level function
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	206 \function{IS_LINE_JUNK()}, which filters out lines without visible
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	207 characters, except for at most one pound character (\character{\#}).
23300 b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	208 As of Python 2.3, the underlying \class{SequenceMatcher} class
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	209 does a dynamic analysis of which lines are so frequent as to
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	210 constitute noise, and this usually works better than the pre-2.3
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	211 default.
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	212
23300 b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	213 \var{charjunk}: A function that accepts a character (a string of
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	214 length 1), and returns if the character is junk, or false if not.
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	215 The default is module-level function \function{IS_CHARACTER_JUNK()},
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	216 which filters out whitespace characters (a blank or tab; note: bad
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	217 idea to include newline in this!).
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	218
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	219 \file{Tools/scripts/ndiff.py} is a command-line front-end to this
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	220 function.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	221
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	222 \begin{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	223 >>> diff = ndiff('one\ntwo\nthree\n'.splitlines(1),
26556 242ad5c592cc Remove extra ")" in example. Fred Drake <fdrake@acm.org> parents: 23300 diff changeset	224 ... 'ore\ntree\nemu\n'.splitlines(1))
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	225 >>> print ''.join(diff),
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	226 - one
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	227 ? ^
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	228 + ore
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	229 ? ^
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	230 - two
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	231 - three
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	232 ? -
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	233 + tree
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	234 + emu
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	235 \end{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	236 \end{funcdesc}
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	237
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	238 \begin{funcdesc}{restore}{sequence, which}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	239 Return one of the two sequences that generated a delta.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	240
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	241 Given a \var{sequence} produced by \method{Differ.compare()} or
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	242 \function{ndiff()}, extract lines originating from file 1 or 2
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	243 (parameter \var{which}), stripping off line prefixes.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	244
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	245 Example:
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	246
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	247 \begin{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	248 >>> diff = ndiff('one\ntwo\nthree\n'.splitlines(1),
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	249 ... 'ore\ntree\nemu\n'.splitlines(1))
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	250 >>> diff = list(diff) # materialize the generated delta into a list
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	251 >>> print ''.join(restore(diff, 1)),
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	252 one
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	253 two
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	254 three
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	255 >>> print ''.join(restore(diff, 2)),
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	256 ore
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	257 tree
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	258 emu
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	259 \end{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	260
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	261 \end{funcdesc}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	262
29398 e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	263 \begin{funcdesc}{unified_diff}{a, b\optional{, fromfile\optional{, tofile
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	264 \optional{, fromfiledate\optional{, tofiledate\optional{, n
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	265 \optional{, lineterm}}}}}}}
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	266 Compare \var{a} and \var{b} (lists of strings); return a
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	267 delta (a generator generating the delta lines) in unified diff
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	268 format.
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	269
29398 e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	270 Unified diffs are a compact way of showing just the lines that have
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	271 changed plus a few lines of context. The changes are shown in a
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	272 inline style (instead of separate before/after blocks). The number
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	273 of context lines is set by \var{n} which defaults to three.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	274
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	275 By default, the diff control lines (those with \code{---}, \code{+++},
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	276 or \code{@@}) are created with a trailing newline. This is helpful so
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	277 that inputs created from \function{file.readlines()} result in diffs
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	278 that are suitable for use with \function{file.writelines()} since both
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	279 the inputs and outputs have trailing newlines.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	280
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	281 For inputs that do not have trailing newlines, set the \var{lineterm}
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	282 argument to \code{""} so that the output will be uniformly newline free.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	283
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	284 The context diff format normally has a header for filenames and
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	285 modification times. Any or all of these may be specified using strings for
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	286 \var{fromfile}, \var{tofile}, \var{fromfiledate}, and \var{tofiledate}.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	287 The modification times are normally expressed in the format returned by
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	288 \function{time.ctime()}. If not specified, the strings default to blanks.
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	289
e6b0a406dc31 Document context_diff() and unified_diff() Raymond Hettinger <python@rcn.com> parents: 26556 diff changeset	290 \file{Tools/scripts/diff.py} is a command-line front-end for this
29404 8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	291 function.
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	292
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	293 \versionadded{2.3}
5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	294 \end{funcdesc}
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	295
20677 f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	296 \begin{funcdesc}{IS_LINE_JUNK}{line}
f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	297 Return true for ignorable lines. The line \var{line} is ignorable
f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	298 if \var{line} is blank or contains a single \character{\#},
f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	299 otherwise it is not ignorable. Used as a default for parameter
23300 b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	300 \var{linejunk} in \function{ndiff()} before Python 2.3.
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	301 \end{funcdesc}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	302
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	303
20677 f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	304 \begin{funcdesc}{IS_CHARACTER_JUNK}{ch}
f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	305 Return true for ignorable characters. The character \var{ch} is
f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	306 ignorable if \var{ch} is a space or tab, otherwise it is not
f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	307 ignorable. Used as a default for parameter \var{charjunk} in
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	308 \function{ndiff()}.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	309 \end{funcdesc}
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	310
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	311
17382 d368552c2b72 Add reference to the DDJ article discussing a similar algorithm. Fred Drake <fdrake@acm.org> parents: 16758 diff changeset	312 \begin{seealso}
31410 6e3758ed1ef4 add direct link to the article in DDJ Fred Drake <fdrake@acm.org> parents: 31275 diff changeset	313 \seetitle[http://www.ddj.com/documents/s=1103/ddj8807c/]
6e3758ed1ef4 add direct link to the article in DDJ Fred Drake <fdrake@acm.org> parents: 31275 diff changeset	314 {Pattern Matching: The Gestalt Approach}{Discussion of a
17382 d368552c2b72 Add reference to the DDJ article discussing a similar algorithm. Fred Drake <fdrake@acm.org> parents: 16758 diff changeset	315 similar algorithm by John W. Ratcliff and D. E. Metzener.
d368552c2b72 Add reference to the DDJ article discussing a similar algorithm. Fred Drake <fdrake@acm.org> parents: 16758 diff changeset	316 This was published in
d368552c2b72 Add reference to the DDJ article discussing a similar algorithm. Fred Drake <fdrake@acm.org> parents: 16758 diff changeset	317 \citetitle[http://www.ddj.com/]{Dr. Dobb's Journal} in
d368552c2b72 Add reference to the DDJ article discussing a similar algorithm. Fred Drake <fdrake@acm.org> parents: 16758 diff changeset	318 July, 1988.}
d368552c2b72 Add reference to the DDJ article discussing a similar algorithm. Fred Drake <fdrake@acm.org> parents: 16758 diff changeset	319 \end{seealso}
d368552c2b72 Add reference to the DDJ article discussing a similar algorithm. Fred Drake <fdrake@acm.org> parents: 16758 diff changeset	320
d368552c2b72 Add reference to the DDJ article discussing a similar algorithm. Fred Drake <fdrake@acm.org> parents: 16758 diff changeset	321
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	322 \subsection{SequenceMatcher Objects \label{sequence-matcher}}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	323
17780 a1575dbf7d81 Replace "\begin{classdesc}{SomeClass}{\unspecified}" with Fred Drake <fdrake@acm.org> parents: 17388 diff changeset	324 The \class{SequenceMatcher} class has this constructor:
a1575dbf7d81 Replace "\begin{classdesc}{SomeClass}{\unspecified}" with Fred Drake <fdrake@acm.org> parents: 17388 diff changeset	325
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	326 \begin{classdesc}{SequenceMatcher}{\optional{isjunk\optional{,
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	327 a\optional{, b}}}}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	328 Optional argument \var{isjunk} must be \code{None} (the default) or
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	329 a one-argument function that takes a sequence element and returns
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	330 true if and only if the element is ``junk'' and should be ignored.
20677 f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	331 Passing \code{None} for \var{b} is equivalent to passing
f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	332 \code{lambda x: 0}; in other words, no elements are ignored. For
f614825d326a Enforce a bit of markup consistency. Fred Drake <fdrake@acm.org> parents: 20038 diff changeset	333 example, pass:
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	334
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	335 \begin{verbatim}
16758 8996288a8873 Fix extra backslash in example. Fred Drake <fdrake@acm.org> parents: 16703 diff changeset	336 lambda x: x in " \t"
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	337 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	338
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	339 if you're comparing lines as sequences of characters, and don't want
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	340 to synch up on blanks or hard tabs.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	341
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	342 The optional arguments \var{a} and \var{b} are sequences to be
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	343 compared; both default to empty strings. The elements of both
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	344 sequences must be hashable.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	345 \end{classdesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	346
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	347
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	348 \class{SequenceMatcher} objects have the following methods:
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	349
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	350 \begin{methoddesc}{set_seqs}{a, b}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	351 Set the two sequences to be compared.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	352 \end{methoddesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	353
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	354 \class{SequenceMatcher} computes and caches detailed information about
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	355 the second sequence, so if you want to compare one sequence against
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	356 many sequences, use \method{set_seq2()} to set the commonly used
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	357 sequence once and call \method{set_seq1()} repeatedly, once for each
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	358 of the other sequences.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	359
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	360 \begin{methoddesc}{set_seq1}{a}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	361 Set the first sequence to be compared. The second sequence to be
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	362 compared is not changed.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	363 \end{methoddesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	364
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	365 \begin{methoddesc}{set_seq2}{b}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	366 Set the second sequence to be compared. The first sequence to be
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	367 compared is not changed.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	368 \end{methoddesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	369
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	370 \begin{methoddesc}{find_longest_match}{alo, ahi, blo, bhi}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	371 Find longest matching block in \code{\var{a}[\var{alo}:\var{ahi}]}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	372 and \code{\var{b}[\var{blo}:\var{bhi}]}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	373
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	374 If \var{isjunk} was omitted or \code{None},
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	375 \method{get_longest_match()} returns \code{(\var{i}, \var{j},
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	376 \var{k})} such that \code{\var{a}[\var{i}:\var{i}+\var{k}]} is equal
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	377 to \code{\var{b}[\var{j}:\var{j}+\var{k}]}, where
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	378 \code{\var{alo} <= \var{i} <= \var{i}+\var{k} <= \var{ahi}} and
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	379 \code{\var{blo} <= \var{j} <= \var{j}+\var{k} <= \var{bhi}}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	380 For all \code{(\var{i'}, \var{j'}, \var{k'})} meeting those
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	381 conditions, the additional conditions
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	382 \code{\var{k} >= \var{k'}},
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	383 \code{\var{i} <= \var{i'}},
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	384 and if \code{\var{i} == \var{i'}}, \code{\var{j} <= \var{j'}}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	385 are also met.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	386 In other words, of all maximal matching blocks, return one that
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	387 starts earliest in \var{a}, and of all those maximal matching blocks
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	388 that start earliest in \var{a}, return the one that starts earliest
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	389 in \var{b}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	390
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	391 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	392 >>> s = SequenceMatcher(None, " abcd", "abcd abcd")
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	393 >>> s.find_longest_match(0, 5, 0, 9)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	394 (0, 4, 5)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	395 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	396
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	397 If \var{isjunk} was provided, first the longest matching block is
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	398 determined as above, but with the additional restriction that no
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	399 junk element appears in the block. Then that block is extended as
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	400 far as possible by matching (only) junk elements on both sides.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	401 So the resulting block never matches on junk except as identical
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	402 junk happens to be adjacent to an interesting match.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	403
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	404 Here's the same example as before, but considering blanks to be junk.
16703 8172906c6dc8 Improve accuracy. In the .tex file, note the new "% BUG:" comments: an Tim Peters <tim.peters@gmail.com> parents: 16682 diff changeset	405 That prevents \code{' abcd'} from matching the \code{' abcd'} at the
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	406 tail end of the second sequence directly. Instead only the
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	407 \code{'abcd'} can match, and matches the leftmost \code{'abcd'} in
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	408 the second sequence:
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	409
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	410 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	411 >>> s = SequenceMatcher(lambda x: x==" ", " abcd", "abcd abcd")
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	412 >>> s.find_longest_match(0, 5, 0, 9)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	413 (1, 0, 4)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	414 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	415
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	416 If no blocks match, this returns \code{(\var{alo}, \var{blo}, 0)}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	417 \end{methoddesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	418
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	419 \begin{methoddesc}{get_matching_blocks}{}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	420 Return list of triples describing matching subsequences.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	421 Each triple is of the form \code{(\var{i}, \var{j}, \var{n})}, and
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	422 means that \code{\var{a}[\var{i}:\var{i}+\var{n}] ==
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	423 \var{b}[\var{j}:\var{j}+\var{n}]}. The triples are monotonically
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	424 increasing in \var{i} and \var{j}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	425
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	426 The last triple is a dummy, and has the value \code{(len(\var{a}),
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	427 len(\var{b}), 0)}. It is the only triple with \code{\var{n} == 0}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	428 % Explain why a dummy is used!
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	429
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	430 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	431 >>> s = SequenceMatcher(None, "abxcd", "abcd")
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	432 >>> s.get_matching_blocks()
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	433 [(0, 0, 2), (3, 2, 2), (5, 4, 0)]
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	434 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	435 \end{methoddesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	436
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	437 \begin{methoddesc}{get_opcodes}{}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	438 Return list of 5-tuples describing how to turn \var{a} into \var{b}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	439 Each tuple is of the form \code{(\var{tag}, \var{i1}, \var{i2},
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	440 \var{j1}, \var{j2})}. The first tuple has \code{\var{i1} ==
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	441 \var{j1} == 0}, and remaining tuples have \var{i1} equal to the
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	442 \var{i2} from the preceeding tuple, and, likewise, \var{j1} equal to
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	443 the previous \var{j2}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	444
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	445 The \var{tag} values are strings, with these meanings:
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	446
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	447 \begin{tableii}{l\|l}{code}{Value}{Meaning}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	448 \lineii{'replace'}{\code{\var{a}[\var{i1}:\var{i2}]} should be
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	449 replaced by \code{\var{b}[\var{j1}:\var{j2}]}.}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	450 \lineii{'delete'}{\code{\var{a}[\var{i1}:\var{i2}]} should be
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	451 deleted. Note that \code{\var{j1} == \var{j2}} in
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	452 this case.}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	453 \lineii{'insert'}{\code{\var{b}[\var{j1}:\var{j2}]} should be
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	454 inserted at \code{\var{a}[\var{i1}:\var{i1}]}.
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	455 Note that \code{\var{i1} == \var{i2}} in this
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	456 case.}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	457 \lineii{'equal'}{\code{\var{a}[\var{i1}:\var{i2}] ==
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	458 \var{b}[\var{j1}:\var{j2}]} (the sub-sequences are
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	459 equal).}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	460 \end{tableii}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	461
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	462 For example:
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	463
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	464 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	465 >>> a = "qabxcd"
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	466 >>> b = "abycdf"
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	467 >>> s = SequenceMatcher(None, a, b)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	468 >>> for tag, i1, i2, j1, j2 in s.get_opcodes():
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	469 ... print ("%7s a[%d:%d] (%s) b[%d:%d] (%s)" %
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	470 ... (tag, i1, i2, a[i1:i2], j1, j2, b[j1:j2]))
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	471 delete a[0:1] (q) b[0:0] ()
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	472 equal a[1:3] (ab) b[0:2] (ab)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	473 replace a[3:4] (x) b[2:3] (y)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	474 equal a[4:6] (cd) b[3:5] (cd)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	475 insert a[6:6] () b[5:6] (f)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	476 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	477 \end{methoddesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	478
29404 8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	479 \begin{methoddesc}{get_grouped_opcodes}{\optional{n}}
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	480 Return a generator of groups with up to \var{n} lines of context.
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	481
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	482 Starting with the groups returned by \method{get_opcodes()},
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	483 this method splits out smaller change clusters and eliminates
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	484 intervening ranges which have no changes.
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	485
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	486 The groups are returned in the same format as \method{get_opcodes()}.
33462 5876636ca8c6 HtmlDiff corrections from Dan Gass, + trimmed trailing whitespace. Tim Peters <tim.peters@gmail.com> parents: 33448 diff changeset	487 \versionadded{2.3}
29404 8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	488 \end{methoddesc}
8c5a6853a02a Add docs for get_grouped_opcodes(). Raymond Hettinger <python@rcn.com> parents: 29398 diff changeset	489
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	490 \begin{methoddesc}{ratio}{}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	491 Return a measure of the sequences' similarity as a float in the
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	492 range [0, 1].
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	493
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	494 Where T is the total number of elements in both sequences, and M is
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	495 the number of matches, this is 2.0*M / T. Note that this is
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	496 \code{1.0} if the sequences are identical, and \code{0.0} if they
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	497 have nothing in common.
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	498
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	499 This is expensive to compute if \method{get_matching_blocks()} or
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	500 \method{get_opcodes()} hasn't already been called, in which case you
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	501 may want to try \method{quick_ratio()} or
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	502 \method{real_quick_ratio()} first to get an upper bound.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	503 \end{methoddesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	504
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	505 \begin{methoddesc}{quick_ratio}{}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	506 Return an upper bound on \method{ratio()} relatively quickly.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	507
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	508 This isn't defined beyond that it is an upper bound on
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	509 \method{ratio()}, and is faster to compute.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	510 \end{methoddesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	511
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	512 \begin{methoddesc}{real_quick_ratio}{}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	513 Return an upper bound on \method{ratio()} very quickly.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	514
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	515 This isn't defined beyond that it is an upper bound on
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	516 \method{ratio()}, and is faster to compute than either
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	517 \method{ratio()} or \method{quick_ratio()}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	518 \end{methoddesc}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	519
16703 8172906c6dc8 Improve accuracy. In the .tex file, note the new "% BUG:" comments: an Tim Peters <tim.peters@gmail.com> parents: 16682 diff changeset	520 The three methods that return the ratio of matching to total characters
8172906c6dc8 Improve accuracy. In the .tex file, note the new "% BUG:" comments: an Tim Peters <tim.peters@gmail.com> parents: 16682 diff changeset	521 can give different results due to differing levels of approximation,
8172906c6dc8 Improve accuracy. In the .tex file, note the new "% BUG:" comments: an Tim Peters <tim.peters@gmail.com> parents: 16682 diff changeset	522 although \method{quick_ratio()} and \method{real_quick_ratio()} are always
8172906c6dc8 Improve accuracy. In the .tex file, note the new "% BUG:" comments: an Tim Peters <tim.peters@gmail.com> parents: 16682 diff changeset	523 at least as large as \method{ratio()}:
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	524
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	525 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	526 >>> s = SequenceMatcher(None, "abcd", "bcde")
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	527 >>> s.ratio()
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	528 0.75
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	529 >>> s.quick_ratio()
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	530 0.75
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	531 >>> s.real_quick_ratio()
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	532 1.0
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	533 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	534
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	535
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	536 \subsection{SequenceMatcher Examples \label{sequencematcher-examples}}
16682 3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	537
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	538
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	539 This example compares two strings, considering blanks to be ``junk:''
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	540
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	541 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	542 >>> s = SequenceMatcher(lambda x: x == " ",
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	543 ... "private Thread currentThread;",
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	544 ... "private volatile Thread currentThread;")
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	545 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	546
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	547 \method{ratio()} returns a float in [0, 1], measuring the similarity
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	548 of the sequences. As a rule of thumb, a \method{ratio()} value over
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	549 0.6 means the sequences are close matches:
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	550
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	551 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	552 >>> print round(s.ratio(), 3)
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	553 0.866
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	554 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	555
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	556 If you're only interested in where the sequences match,
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	557 \method{get_matching_blocks()} is handy:
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	558
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	559 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	560 >>> for block in s.get_matching_blocks():
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	561 ... print "a[%d] and b[%d] match for %d elements" % block
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	562 a[0] and b[0] match for 8 elements
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	563 a[8] and b[17] match for 6 elements
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	564 a[14] and b[23] match for 15 elements
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	565 a[29] and b[38] match for 0 elements
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	566 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	567
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	568 Note that the last tuple returned by \method{get_matching_blocks()} is
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	569 always a dummy, \code{(len(\var{a}), len(\var{b}), 0)}, and this is
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	570 the only case in which the last tuple element (number of elements
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	571 matched) is \code{0}.
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	572
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	573 If you want to know how to change the first sequence into the second,
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	574 use \method{get_opcodes()}:
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	575
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	576 \begin{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	577 >>> for opcode in s.get_opcodes():
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	578 ... print "%6s a[%d:%d] b[%d:%d]" % opcode
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	579 equal a[0:8] b[0:8]
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	580 insert a[8:8] b[8:17]
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	581 equal a[8:14] b[17:23]
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	582 equal a[14:29] b[23:38]
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	583 \end{verbatim}
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	584
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	585 See also the function \function{get_close_matches()} in this module,
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	586 which shows how simple code building on \class{SequenceMatcher} can be
3cb00cbe7455 Documentation for the difflib module, converted from the module docstrings. Fred Drake <fdrake@acm.org> parents: diff changeset	587 used to do useful work.
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	588
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	589
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	590 \subsection{Differ Objects \label{differ-objects}}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	591
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	592 Note that \class{Differ}-generated deltas make no claim to be
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	593 \strong{minimal} diffs. To the contrary, minimal diffs are often
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	594 counter-intuitive, because they synch up anywhere possible, sometimes
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	595 accidental matches 100 pages apart. Restricting synch points to
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	596 contiguous matches preserves some notion of locality, at the
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	597 occasional cost of producing a longer diff.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	598
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	599 The \class{Differ} class has this constructor:
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	600
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	601 \begin{classdesc}{Differ}{\optional{linejunk\optional{, charjunk}}}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	602 Optional keyword parameters \var{linejunk} and \var{charjunk} are
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	603 for filter functions (or \code{None}):
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	604
23300 b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	605 \var{linejunk}: A function that accepts a single string
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	606 argument, and returns true if the string is junk. The default is
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	607 \code{None}, meaning that no line is considered junk.
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	608
23300 b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	609 \var{charjunk}: A function that accepts a single character argument
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	610 (a string of length 1), and returns true if the character is junk.
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	611 The default is \code{None}, meaning that no character is
b5f6e9f6e7f4 Mostly in SequenceMatcher.{__chain_b, find_longest_match}: Tim Peters <tim.peters@gmail.com> parents: 21106 diff changeset	612 considered junk.
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	613 \end{classdesc}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	614
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	615 \class{Differ} objects are used (deltas generated) via a single
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	616 method:
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	617
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	618 \begin{methoddesc}{compare}{a, b}
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	619 Compare two sequences of lines, and generate the delta (a sequence
8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	620 of lines).
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	621
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	622 Each sequence must contain individual single-line strings ending
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	623 with newlines. Such sequences can be obtained from the
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	624 \method{readlines()} method of file-like objects. The delta generated
8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	625 also consists of newline-terminated strings, ready to be printed as-is
21106 3827f136e0d6 writeline() --> writelines() Fred Drake <fdrake@acm.org> parents: 20677 diff changeset	626 via the \method{writelines()} method of a file-like object.
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	627 \end{methoddesc}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	628
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	629
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	630 \subsection{Differ Example \label{differ-examples}}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	631
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	632 This example compares two texts. First we set up the texts, sequences
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	633 of individual single-line strings ending with newlines (such sequences
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	634 can also be obtained from the \method{readlines()} method of file-like
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	635 objects):
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	636
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	637 \begin{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	638 >>> text1 = ''' 1. Beautiful is better than ugly.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	639 ... 2. Explicit is better than implicit.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	640 ... 3. Simple is better than complex.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	641 ... 4. Complex is better than complicated.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	642 ... '''.splitlines(1)
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	643 >>> len(text1)
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	644 4
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	645 >>> text1[0][-1]
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	646 '\n'
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	647 >>> text2 = ''' 1. Beautiful is better than ugly.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	648 ... 3. Simple is better than complex.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	649 ... 4. Complicated is better than complex.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	650 ... 5. Flat is better than nested.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	651 ... '''.splitlines(1)
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	652 \end{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	653
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	654 Next we instantiate a Differ object:
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	655
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	656 \begin{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	657 >>> d = Differ()
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	658 \end{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	659
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	660 Note that when instantiating a \class{Differ} object we may pass
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	661 functions to filter out line and character ``junk.'' See the
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	662 \method{Differ()} constructor for details.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	663
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	664 Finally, we compare the two:
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	665
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	666 \begin{verbatim}
20038 8a6f2ee6eaba Make difflib.ndiff() and difflib.Differ.compare() generators. This Tim Peters <tim.peters@gmail.com> parents: 19232 diff changeset	667 >>> result = list(d.compare(text1, text2))
19232 65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	668 \end{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	669
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	670 \code{result} is a list of strings, so let's pretty-print it:
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	671
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	672 \begin{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	673 >>> from pprint import pprint
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	674 >>> pprint(result)
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	675 [' 1. Beautiful is better than ugly.\n',
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	676 '- 2. Explicit is better than implicit.\n',
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	677 '- 3. Simple is better than complex.\n',
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	678 '+ 3. Simple is better than complex.\n',
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	679 '? ++ \n',
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	680 '- 4. Complex is better than complicated.\n',
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	681 '? ^ ---- ^ \n',
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	682 '+ 4. Complicated is better than complex.\n',
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	683 '? ++++ ^ ^ \n',
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	684 '+ 5. Flat is better than nested.\n']
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	685 \end{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	686
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	687 As a single multi-line string it looks like this:
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	688
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	689 \begin{verbatim}
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	690 >>> import sys
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	691 >>> sys.stdout.writelines(result)
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	692 1. Beautiful is better than ugly.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	693 - 2. Explicit is better than implicit.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	694 - 3. Simple is better than complex.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	695 + 3. Simple is better than complex.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	696 ? ++
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	697 - 4. Complex is better than complicated.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	698 ? ^ ---- ^
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	699 + 4. Complicated is better than complex.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	700 ? ++++ ^ ^
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	701 + 5. Flat is better than nested.
65885ea76c37 David Goodger <dgoodger@atsautomation.com>: Fred Drake <fdrake@acm.org> parents: 17785 diff changeset	702 \end{verbatim}

Mercurial > cpython-lru_cache-weakref

annotate Doc/lib/libdifflib.tex @ 33462:5876636ca8c6 legacy-trunk