cpython/Lib/re/__init__.py

428 lines
17 KiB
Python
Raw Normal View History

#
# Secret Labs' Regular Expression Engine
#
# re-compatible interface for the sre matching engine
#
# Copyright (c) 1998-2001 by Secret Labs AB. All rights reserved.
#
# This version of the SRE library can be redistributed under CNRI's
# Python 1.6 license. For any other use, please contact Secret Labs
# AB (info@pythonware.com).
#
# Portions of this engine have been developed in cooperation with
# CNRI. Hewlett-Packard provided funding for 1.6 integration and
# other compatibility work.
#
2001-09-04 16:20:06 -03:00
r"""Support for regular expressions (RE).
This module provides regular expression matching operations similar to
those found in Perl. It supports both 8-bit and Unicode strings; both
the pattern and the strings being processed can contain null bytes and
characters outside the US ASCII range.
Regular expressions can contain both special and ordinary characters.
Most ordinary characters, like "A", "a", or "0", are the simplest
regular expressions; they simply match themselves. You can
concatenate ordinary characters, so last matches the string 'last'.
The special characters are:
"." Matches any character except a newline.
"^" Matches the start of the string.
Merged revisions 60151-60159,60161-60168,60170,60172-60173,60175 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r60151 | christian.heimes | 2008-01-21 14:11:15 +0100 (Mon, 21 Jan 2008) | 1 line A bunch of header files were not listed as dependencies for object files. Changes to files like Parser/parser.h weren't picked up by make. ........ r60152 | georg.brandl | 2008-01-21 15:16:46 +0100 (Mon, 21 Jan 2008) | 3 lines #1087741: make mmap.mmap the type of mmap objects, not a factory function. Allow it to be subclassed. ........ r60153 | georg.brandl | 2008-01-21 15:18:14 +0100 (Mon, 21 Jan 2008) | 2 lines mmap is an extension module. ........ r60154 | georg.brandl | 2008-01-21 17:28:13 +0100 (Mon, 21 Jan 2008) | 2 lines Fix example. ........ r60155 | georg.brandl | 2008-01-21 17:34:07 +0100 (Mon, 21 Jan 2008) | 2 lines #1555501: document plistlib and move it to the general library. ........ r60156 | georg.brandl | 2008-01-21 17:36:00 +0100 (Mon, 21 Jan 2008) | 2 lines Add a stub for bundlebuilder documentation. ........ r60157 | georg.brandl | 2008-01-21 17:46:58 +0100 (Mon, 21 Jan 2008) | 2 lines Removing bundlebuilder docs again -- it's not to be used anymore (see #779825). ........ r60158 | georg.brandl | 2008-01-21 17:51:51 +0100 (Mon, 21 Jan 2008) | 2 lines #997912: acknowledge nested scopes in tutorial. ........ r60159 | vinay.sajip | 2008-01-21 18:02:26 +0100 (Mon, 21 Jan 2008) | 1 line Fix: #1836: Off-by-one bug in TimedRotatingFileHandler rollover calculation. Patch thanks to Kathryn M. Kowalski. ........ r60161 | georg.brandl | 2008-01-21 18:13:03 +0100 (Mon, 21 Jan 2008) | 2 lines Adapt pydoc to new doc URLs. ........ r60162 | georg.brandl | 2008-01-21 18:17:00 +0100 (Mon, 21 Jan 2008) | 2 lines Fix old link. ........ r60163 | georg.brandl | 2008-01-21 18:22:06 +0100 (Mon, 21 Jan 2008) | 2 lines #1726198: replace while 1: fp.readline() with file iteration. ........ r60164 | georg.brandl | 2008-01-21 18:29:23 +0100 (Mon, 21 Jan 2008) | 2 lines Clarify $ behavior in re docstring. #1631394. ........ r60165 | vinay.sajip | 2008-01-21 18:39:22 +0100 (Mon, 21 Jan 2008) | 1 line Minor documentation change - hyperlink tidied up. ........ r60166 | georg.brandl | 2008-01-21 18:42:40 +0100 (Mon, 21 Jan 2008) | 2 lines #1530959: change distutils build dir for --with-pydebug python builds. ........ r60167 | vinay.sajip | 2008-01-21 19:16:05 +0100 (Mon, 21 Jan 2008) | 1 line Updated to include news on recent logging fixes and documentation changes. ........ r60168 | georg.brandl | 2008-01-21 19:35:49 +0100 (Mon, 21 Jan 2008) | 3 lines Issue #1882: when compiling code from a string, encoding cookies in the second line of code were not always recognized correctly. ........ r60170 | georg.brandl | 2008-01-21 19:36:51 +0100 (Mon, 21 Jan 2008) | 2 lines Add NEWS entry for #1882. ........ r60172 | georg.brandl | 2008-01-21 19:41:24 +0100 (Mon, 21 Jan 2008) | 2 lines Use original location of document, which has translations. ........ r60173 | walter.doerwald | 2008-01-21 21:18:04 +0100 (Mon, 21 Jan 2008) | 2 lines Follow PEP 8 in module docstring. ........ r60175 | georg.brandl | 2008-01-21 21:20:53 +0100 (Mon, 21 Jan 2008) | 2 lines Adapt to latest doctools refactoring. ........
2008-01-21 16:36:10 -04:00
"$" Matches the end of the string or just before the newline at
the end of the string.
"*" Matches 0 or more (greedy) repetitions of the preceding RE.
Greedy means that it will match as many repetitions as possible.
"+" Matches 1 or more (greedy) repetitions of the preceding RE.
"?" Matches 0 or 1 (greedy) of the preceding RE.
*?,+?,?? Non-greedy versions of the previous three special characters.
{m,n} Matches from m to n repetitions of the preceding RE.
{m,n}? Non-greedy version of the above.
Merged revisions 60284-60349 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r60286 | christian.heimes | 2008-01-25 15:54:23 +0100 (Fri, 25 Jan 2008) | 1 line setup.py doesn't pick up changes to a header file ........ r60287 | christian.heimes | 2008-01-25 16:52:11 +0100 (Fri, 25 Jan 2008) | 2 lines Added the Python core headers Include/*.h and pyconfig.h as dependencies for the extensions in Modules/ It forces a rebuild of all extensions when a header files has been modified ........ r60291 | raymond.hettinger | 2008-01-25 20:24:46 +0100 (Fri, 25 Jan 2008) | 4 lines Changes 54857 and 54840 broke code and were reverted in Py2.5 just before it was released, but that reversion never made it to the Py2.6 head. ........ r60296 | guido.van.rossum | 2008-01-25 20:50:26 +0100 (Fri, 25 Jan 2008) | 2 lines Rewrite the list_inline_repeat overflow check slightly differently. ........ r60301 | thomas.wouters | 2008-01-25 22:09:34 +0100 (Fri, 25 Jan 2008) | 4 lines Use the right (portable) definition of the max of a Py_ssize_t. ........ r60303 | thomas.wouters | 2008-01-26 02:47:05 +0100 (Sat, 26 Jan 2008) | 5 lines Make 'testall' work again when building in a separate directory. test_distutils still fails when doing that. ........ r60305 | neal.norwitz | 2008-01-26 06:54:48 +0100 (Sat, 26 Jan 2008) | 3 lines Prevent this test from failing if there are transient network problems by retrying the host for up to 3 times. ........ r60306 | neal.norwitz | 2008-01-26 08:26:12 +0100 (Sat, 26 Jan 2008) | 12 lines Use a condition variable (threading.Event) rather than sleeps and checking a global to determine when the server is ready to be used. This slows the test down, but should make it correct. There was a race condition before where the server could have assigned a port, yet it wasn't ready to serve requests. If the client sent a request before the server was completely ready, it would get an exception. There was machinery to try to handle this condition. All of that should be unnecessary and removed if this change works. A NOTE was added as a comment about what needs to be fixed. The buildbots will tell us if there are more errors or if this test is now stable. ........ r60307 | neal.norwitz | 2008-01-26 08:38:03 +0100 (Sat, 26 Jan 2008) | 3 lines Fix exception in tearDown on ppc buildbot. If there's no directory, that shouldn't cause the test to fail. Just like it setUp. ........ r60308 | raymond.hettinger | 2008-01-26 09:19:06 +0100 (Sat, 26 Jan 2008) | 3 lines Make PySet_Add() work with frozensets. Works like PyTuple_SetItem() to build-up values in a brand new frozenset. ........ r60309 | neal.norwitz | 2008-01-26 09:26:00 +0100 (Sat, 26 Jan 2008) | 1 line The OS X buildbot had errors with the unavailable exceptions disabled. Restore it. ........ r60310 | raymond.hettinger | 2008-01-26 09:37:28 +0100 (Sat, 26 Jan 2008) | 4 lines Let marshal build-up sets and frozensets one element at a time. Saves the unnecessary creation of a tuple as intermediate container. ........ r60311 | raymond.hettinger | 2008-01-26 09:41:13 +0100 (Sat, 26 Jan 2008) | 1 line Update test code for change to PySet_Add(). ........ r60312 | raymond.hettinger | 2008-01-26 10:31:11 +0100 (Sat, 26 Jan 2008) | 1 line Revert PySet_Add() changes. ........ r60314 | georg.brandl | 2008-01-26 10:43:35 +0100 (Sat, 26 Jan 2008) | 2 lines #1934: fix os.path.isabs docs. ........ r60316 | georg.brandl | 2008-01-26 12:00:18 +0100 (Sat, 26 Jan 2008) | 2 lines Add missing things in re docstring. ........ r60317 | georg.brandl | 2008-01-26 12:02:22 +0100 (Sat, 26 Jan 2008) | 2 lines Slashes allowed on Windows. ........ r60319 | georg.brandl | 2008-01-26 14:41:21 +0100 (Sat, 26 Jan 2008) | 2 lines Fix markup again. ........ r60320 | andrew.kuchling | 2008-01-26 14:50:51 +0100 (Sat, 26 Jan 2008) | 1 line Add some items ........ r60321 | georg.brandl | 2008-01-26 15:02:38 +0100 (Sat, 26 Jan 2008) | 2 lines Clarify "b" mode under Unix. ........ r60322 | georg.brandl | 2008-01-26 15:03:47 +0100 (Sat, 26 Jan 2008) | 3 lines #1940: make it possible to use curses.filter() before curses.initscr() as the documentation says. ........ r60324 | georg.brandl | 2008-01-26 15:14:20 +0100 (Sat, 26 Jan 2008) | 3 lines #1473257: add generator.gi_code attribute that refers to the original code object backing the generator. Patch by Collin Winter. ........ r60325 | georg.brandl | 2008-01-26 15:19:22 +0100 (Sat, 26 Jan 2008) | 2 lines Move C API entries to the corresponding section. ........ r60326 | christian.heimes | 2008-01-26 17:43:35 +0100 (Sat, 26 Jan 2008) | 1 line Unit test fix from Giampaolo Rodola, #1938 ........ r60327 | gregory.p.smith | 2008-01-26 19:51:05 +0100 (Sat, 26 Jan 2008) | 2 lines Update docs for new callpack params added in r60188 ........ r60329 | neal.norwitz | 2008-01-26 21:24:36 +0100 (Sat, 26 Jan 2008) | 3 lines Cleanup the code a bit. test_rfind is failing on PPC and PPC64 buildbots, this might fix the problem. ........ r60330 | neal.norwitz | 2008-01-26 22:02:45 +0100 (Sat, 26 Jan 2008) | 1 line Always try to remove the test file even if close raises an exception ........ r60331 | neal.norwitz | 2008-01-26 22:21:59 +0100 (Sat, 26 Jan 2008) | 3 lines Reduce the race condition by signalling when the server is ready and not trying to connect before. ........ r60334 | neal.norwitz | 2008-01-27 00:13:46 +0100 (Sun, 27 Jan 2008) | 5 lines On some systems (e.g., Ubuntu on hppa) the flush() doesn't cause the exception, but the close() does. Will backport. ........ r60335 | neal.norwitz | 2008-01-27 00:14:17 +0100 (Sun, 27 Jan 2008) | 2 lines Consistently use tempfile.tempdir for the db_home directory. ........ r60338 | neal.norwitz | 2008-01-27 02:44:05 +0100 (Sun, 27 Jan 2008) | 4 lines Eliminate the sleeps that assume the server will start in .5 seconds. This should make the test less flaky. It also speeds up the test by about 75% on my box (20+ seconds -> ~4 seconds). ........ r60342 | neal.norwitz | 2008-01-27 06:02:34 +0100 (Sun, 27 Jan 2008) | 6 lines Try to prevent this test from being flaky. We might need a sleep in here which isn't as bad as it sounds. The close() *should* raise an exception, so if it didn't we should give more time to sync and really raise it. Will backport. ........ r60344 | jeffrey.yasskin | 2008-01-27 06:40:35 +0100 (Sun, 27 Jan 2008) | 3 lines Make rational.gcd() public and allow Rational to take decimal strings, per Raymond's advice. ........ r60345 | neal.norwitz | 2008-01-27 08:36:03 +0100 (Sun, 27 Jan 2008) | 3 lines Mostly reformat. Also set an error and return NULL if neither MS_WINDOWS nor UNIX is defined. This may have caused problems on cygwin. ........ r60346 | neal.norwitz | 2008-01-27 08:37:38 +0100 (Sun, 27 Jan 2008) | 3 lines Use int for the sign rather than a char. char can be signed or unsigned. It's system dependent. This might fix the problem with test_rfind failing. ........ r60347 | neal.norwitz | 2008-01-27 08:41:33 +0100 (Sun, 27 Jan 2008) | 1 line Add stdarg include for va_list to get this to compile on cygwin ........ r60348 | raymond.hettinger | 2008-01-27 11:13:57 +0100 (Sun, 27 Jan 2008) | 1 line Docstring nit ........ r60349 | raymond.hettinger | 2008-01-27 11:47:55 +0100 (Sun, 27 Jan 2008) | 1 line Removed an unnecessary and confusing paragraph from the namedtuple docs. ........
2008-01-27 11:18:18 -04:00
"\\" Either escapes special characters or signals a special sequence.
[] Indicates a set of characters.
A "^" as the first character indicates a complementing set.
"|" A|B, creates an RE that will match either A or B.
(...) Matches the RE inside the parentheses.
The contents can be retrieved or matched later in the string.
(?aiLmsux) The letters set the corresponding flags defined below.
(?:...) Non-grouping version of regular parentheses.
(?P<name>...) The substring matched by the group is accessible by name.
(?P=name) Matches the text matched earlier by the group named name.
(?#...) A comment; ignored.
(?=...) Matches if ... matches next, but doesn't consume the string.
(?!...) Matches if ... doesn't match next.
Merged revisions 60284-60349 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r60286 | christian.heimes | 2008-01-25 15:54:23 +0100 (Fri, 25 Jan 2008) | 1 line setup.py doesn't pick up changes to a header file ........ r60287 | christian.heimes | 2008-01-25 16:52:11 +0100 (Fri, 25 Jan 2008) | 2 lines Added the Python core headers Include/*.h and pyconfig.h as dependencies for the extensions in Modules/ It forces a rebuild of all extensions when a header files has been modified ........ r60291 | raymond.hettinger | 2008-01-25 20:24:46 +0100 (Fri, 25 Jan 2008) | 4 lines Changes 54857 and 54840 broke code and were reverted in Py2.5 just before it was released, but that reversion never made it to the Py2.6 head. ........ r60296 | guido.van.rossum | 2008-01-25 20:50:26 +0100 (Fri, 25 Jan 2008) | 2 lines Rewrite the list_inline_repeat overflow check slightly differently. ........ r60301 | thomas.wouters | 2008-01-25 22:09:34 +0100 (Fri, 25 Jan 2008) | 4 lines Use the right (portable) definition of the max of a Py_ssize_t. ........ r60303 | thomas.wouters | 2008-01-26 02:47:05 +0100 (Sat, 26 Jan 2008) | 5 lines Make 'testall' work again when building in a separate directory. test_distutils still fails when doing that. ........ r60305 | neal.norwitz | 2008-01-26 06:54:48 +0100 (Sat, 26 Jan 2008) | 3 lines Prevent this test from failing if there are transient network problems by retrying the host for up to 3 times. ........ r60306 | neal.norwitz | 2008-01-26 08:26:12 +0100 (Sat, 26 Jan 2008) | 12 lines Use a condition variable (threading.Event) rather than sleeps and checking a global to determine when the server is ready to be used. This slows the test down, but should make it correct. There was a race condition before where the server could have assigned a port, yet it wasn't ready to serve requests. If the client sent a request before the server was completely ready, it would get an exception. There was machinery to try to handle this condition. All of that should be unnecessary and removed if this change works. A NOTE was added as a comment about what needs to be fixed. The buildbots will tell us if there are more errors or if this test is now stable. ........ r60307 | neal.norwitz | 2008-01-26 08:38:03 +0100 (Sat, 26 Jan 2008) | 3 lines Fix exception in tearDown on ppc buildbot. If there's no directory, that shouldn't cause the test to fail. Just like it setUp. ........ r60308 | raymond.hettinger | 2008-01-26 09:19:06 +0100 (Sat, 26 Jan 2008) | 3 lines Make PySet_Add() work with frozensets. Works like PyTuple_SetItem() to build-up values in a brand new frozenset. ........ r60309 | neal.norwitz | 2008-01-26 09:26:00 +0100 (Sat, 26 Jan 2008) | 1 line The OS X buildbot had errors with the unavailable exceptions disabled. Restore it. ........ r60310 | raymond.hettinger | 2008-01-26 09:37:28 +0100 (Sat, 26 Jan 2008) | 4 lines Let marshal build-up sets and frozensets one element at a time. Saves the unnecessary creation of a tuple as intermediate container. ........ r60311 | raymond.hettinger | 2008-01-26 09:41:13 +0100 (Sat, 26 Jan 2008) | 1 line Update test code for change to PySet_Add(). ........ r60312 | raymond.hettinger | 2008-01-26 10:31:11 +0100 (Sat, 26 Jan 2008) | 1 line Revert PySet_Add() changes. ........ r60314 | georg.brandl | 2008-01-26 10:43:35 +0100 (Sat, 26 Jan 2008) | 2 lines #1934: fix os.path.isabs docs. ........ r60316 | georg.brandl | 2008-01-26 12:00:18 +0100 (Sat, 26 Jan 2008) | 2 lines Add missing things in re docstring. ........ r60317 | georg.brandl | 2008-01-26 12:02:22 +0100 (Sat, 26 Jan 2008) | 2 lines Slashes allowed on Windows. ........ r60319 | georg.brandl | 2008-01-26 14:41:21 +0100 (Sat, 26 Jan 2008) | 2 lines Fix markup again. ........ r60320 | andrew.kuchling | 2008-01-26 14:50:51 +0100 (Sat, 26 Jan 2008) | 1 line Add some items ........ r60321 | georg.brandl | 2008-01-26 15:02:38 +0100 (Sat, 26 Jan 2008) | 2 lines Clarify "b" mode under Unix. ........ r60322 | georg.brandl | 2008-01-26 15:03:47 +0100 (Sat, 26 Jan 2008) | 3 lines #1940: make it possible to use curses.filter() before curses.initscr() as the documentation says. ........ r60324 | georg.brandl | 2008-01-26 15:14:20 +0100 (Sat, 26 Jan 2008) | 3 lines #1473257: add generator.gi_code attribute that refers to the original code object backing the generator. Patch by Collin Winter. ........ r60325 | georg.brandl | 2008-01-26 15:19:22 +0100 (Sat, 26 Jan 2008) | 2 lines Move C API entries to the corresponding section. ........ r60326 | christian.heimes | 2008-01-26 17:43:35 +0100 (Sat, 26 Jan 2008) | 1 line Unit test fix from Giampaolo Rodola, #1938 ........ r60327 | gregory.p.smith | 2008-01-26 19:51:05 +0100 (Sat, 26 Jan 2008) | 2 lines Update docs for new callpack params added in r60188 ........ r60329 | neal.norwitz | 2008-01-26 21:24:36 +0100 (Sat, 26 Jan 2008) | 3 lines Cleanup the code a bit. test_rfind is failing on PPC and PPC64 buildbots, this might fix the problem. ........ r60330 | neal.norwitz | 2008-01-26 22:02:45 +0100 (Sat, 26 Jan 2008) | 1 line Always try to remove the test file even if close raises an exception ........ r60331 | neal.norwitz | 2008-01-26 22:21:59 +0100 (Sat, 26 Jan 2008) | 3 lines Reduce the race condition by signalling when the server is ready and not trying to connect before. ........ r60334 | neal.norwitz | 2008-01-27 00:13:46 +0100 (Sun, 27 Jan 2008) | 5 lines On some systems (e.g., Ubuntu on hppa) the flush() doesn't cause the exception, but the close() does. Will backport. ........ r60335 | neal.norwitz | 2008-01-27 00:14:17 +0100 (Sun, 27 Jan 2008) | 2 lines Consistently use tempfile.tempdir for the db_home directory. ........ r60338 | neal.norwitz | 2008-01-27 02:44:05 +0100 (Sun, 27 Jan 2008) | 4 lines Eliminate the sleeps that assume the server will start in .5 seconds. This should make the test less flaky. It also speeds up the test by about 75% on my box (20+ seconds -> ~4 seconds). ........ r60342 | neal.norwitz | 2008-01-27 06:02:34 +0100 (Sun, 27 Jan 2008) | 6 lines Try to prevent this test from being flaky. We might need a sleep in here which isn't as bad as it sounds. The close() *should* raise an exception, so if it didn't we should give more time to sync and really raise it. Will backport. ........ r60344 | jeffrey.yasskin | 2008-01-27 06:40:35 +0100 (Sun, 27 Jan 2008) | 3 lines Make rational.gcd() public and allow Rational to take decimal strings, per Raymond's advice. ........ r60345 | neal.norwitz | 2008-01-27 08:36:03 +0100 (Sun, 27 Jan 2008) | 3 lines Mostly reformat. Also set an error and return NULL if neither MS_WINDOWS nor UNIX is defined. This may have caused problems on cygwin. ........ r60346 | neal.norwitz | 2008-01-27 08:37:38 +0100 (Sun, 27 Jan 2008) | 3 lines Use int for the sign rather than a char. char can be signed or unsigned. It's system dependent. This might fix the problem with test_rfind failing. ........ r60347 | neal.norwitz | 2008-01-27 08:41:33 +0100 (Sun, 27 Jan 2008) | 1 line Add stdarg include for va_list to get this to compile on cygwin ........ r60348 | raymond.hettinger | 2008-01-27 11:13:57 +0100 (Sun, 27 Jan 2008) | 1 line Docstring nit ........ r60349 | raymond.hettinger | 2008-01-27 11:47:55 +0100 (Sun, 27 Jan 2008) | 1 line Removed an unnecessary and confusing paragraph from the namedtuple docs. ........
2008-01-27 11:18:18 -04:00
(?<=...) Matches if preceded by ... (must be fixed length).
(?<!...) Matches if not preceded by ... (must be fixed length).
(?(id/name)yes|no) Matches yes pattern if the group with id/name matched,
the (optional) no pattern otherwise.
The special sequences consist of "\\" and a character from the list
below. If the ordinary character is not on the list, then the
resulting RE will match the second character.
2001-09-04 16:20:06 -03:00
\number Matches the contents of the group of the same number.
\A Matches only at the start of the string.
\Z Matches only at the end of the string.
\b Matches the empty string, but only at the start or end of a word.
\B Matches the empty string, but not at the start or end of a word.
\d Matches any decimal digit; equivalent to the set [0-9] in
bytes patterns or string patterns with the ASCII flag.
In string patterns without the ASCII flag, it will match the whole
range of Unicode digits.
\D Matches any non-digit character; equivalent to [^\d].
\s Matches any whitespace character; equivalent to [ \t\n\r\f\v] in
bytes patterns or string patterns with the ASCII flag.
In string patterns without the ASCII flag, it will match the whole
range of Unicode whitespace characters.
2012-04-29 07:35:55 -03:00
\S Matches any non-whitespace character; equivalent to [^\s].
\w Matches any alphanumeric character; equivalent to [a-zA-Z0-9_]
in bytes patterns or string patterns with the ASCII flag.
In string patterns without the ASCII flag, it will match the
range of Unicode alphanumeric characters (letters plus digits
plus underscore).
With LOCALE, it will match the set [0-9_] plus characters defined
as letters for the current locale.
2001-09-04 16:20:06 -03:00
\W Matches the complement of \w.
\\ Matches a literal backslash.
This module exports the following functions:
match Match a regular expression pattern to the beginning of a string.
fullmatch Match a regular expression pattern to all of a string.
search Search a string for the presence of a pattern.
sub Substitute occurrences of a pattern found in a string.
subn Same as sub, but also return the number of substitutions made.
split Split a string by the occurrences of a pattern.
findall Find all occurrences of a pattern in a string.
finditer Return an iterator yielding a Match object for each match.
compile Compile a pattern into a Pattern object.
purge Clear the regular expression cache.
escape Backslash all non-alphanumerics in a string.
Each function other than purge and escape can take an optional 'flags' argument
consisting of one or more of the following module constants, joined by "|".
A, L, and U are mutually exclusive.
A ASCII For string patterns, make \w, \W, \b, \B, \d, \D
match the corresponding ASCII character categories
(rather than the whole Unicode categories, which is the
default).
For bytes patterns, this flag is the only available
behaviour and needn't be specified.
I IGNORECASE Perform case-insensitive matching.
L LOCALE Make \w, \W, \b, \B, dependent on the current locale.
Merged revisions 60151-60159,60161-60168,60170,60172-60173,60175 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r60151 | christian.heimes | 2008-01-21 14:11:15 +0100 (Mon, 21 Jan 2008) | 1 line A bunch of header files were not listed as dependencies for object files. Changes to files like Parser/parser.h weren't picked up by make. ........ r60152 | georg.brandl | 2008-01-21 15:16:46 +0100 (Mon, 21 Jan 2008) | 3 lines #1087741: make mmap.mmap the type of mmap objects, not a factory function. Allow it to be subclassed. ........ r60153 | georg.brandl | 2008-01-21 15:18:14 +0100 (Mon, 21 Jan 2008) | 2 lines mmap is an extension module. ........ r60154 | georg.brandl | 2008-01-21 17:28:13 +0100 (Mon, 21 Jan 2008) | 2 lines Fix example. ........ r60155 | georg.brandl | 2008-01-21 17:34:07 +0100 (Mon, 21 Jan 2008) | 2 lines #1555501: document plistlib and move it to the general library. ........ r60156 | georg.brandl | 2008-01-21 17:36:00 +0100 (Mon, 21 Jan 2008) | 2 lines Add a stub for bundlebuilder documentation. ........ r60157 | georg.brandl | 2008-01-21 17:46:58 +0100 (Mon, 21 Jan 2008) | 2 lines Removing bundlebuilder docs again -- it's not to be used anymore (see #779825). ........ r60158 | georg.brandl | 2008-01-21 17:51:51 +0100 (Mon, 21 Jan 2008) | 2 lines #997912: acknowledge nested scopes in tutorial. ........ r60159 | vinay.sajip | 2008-01-21 18:02:26 +0100 (Mon, 21 Jan 2008) | 1 line Fix: #1836: Off-by-one bug in TimedRotatingFileHandler rollover calculation. Patch thanks to Kathryn M. Kowalski. ........ r60161 | georg.brandl | 2008-01-21 18:13:03 +0100 (Mon, 21 Jan 2008) | 2 lines Adapt pydoc to new doc URLs. ........ r60162 | georg.brandl | 2008-01-21 18:17:00 +0100 (Mon, 21 Jan 2008) | 2 lines Fix old link. ........ r60163 | georg.brandl | 2008-01-21 18:22:06 +0100 (Mon, 21 Jan 2008) | 2 lines #1726198: replace while 1: fp.readline() with file iteration. ........ r60164 | georg.brandl | 2008-01-21 18:29:23 +0100 (Mon, 21 Jan 2008) | 2 lines Clarify $ behavior in re docstring. #1631394. ........ r60165 | vinay.sajip | 2008-01-21 18:39:22 +0100 (Mon, 21 Jan 2008) | 1 line Minor documentation change - hyperlink tidied up. ........ r60166 | georg.brandl | 2008-01-21 18:42:40 +0100 (Mon, 21 Jan 2008) | 2 lines #1530959: change distutils build dir for --with-pydebug python builds. ........ r60167 | vinay.sajip | 2008-01-21 19:16:05 +0100 (Mon, 21 Jan 2008) | 1 line Updated to include news on recent logging fixes and documentation changes. ........ r60168 | georg.brandl | 2008-01-21 19:35:49 +0100 (Mon, 21 Jan 2008) | 3 lines Issue #1882: when compiling code from a string, encoding cookies in the second line of code were not always recognized correctly. ........ r60170 | georg.brandl | 2008-01-21 19:36:51 +0100 (Mon, 21 Jan 2008) | 2 lines Add NEWS entry for #1882. ........ r60172 | georg.brandl | 2008-01-21 19:41:24 +0100 (Mon, 21 Jan 2008) | 2 lines Use original location of document, which has translations. ........ r60173 | walter.doerwald | 2008-01-21 21:18:04 +0100 (Mon, 21 Jan 2008) | 2 lines Follow PEP 8 in module docstring. ........ r60175 | georg.brandl | 2008-01-21 21:20:53 +0100 (Mon, 21 Jan 2008) | 2 lines Adapt to latest doctools refactoring. ........
2008-01-21 16:36:10 -04:00
M MULTILINE "^" matches the beginning of lines (after a newline)
as well as the string.
"$" matches the end of lines (before a newline) as well
as the end of the string.
S DOTALL "." matches any character at all, including the newline.
X VERBOSE Ignore whitespace and comments for nicer looking RE's.
U UNICODE For compatibility only. Ignored for string patterns (it
is the default), and forbidden for bytes patterns.
This module also defines an exception 'error'.
"""
import enum
from . import _compiler, _parser
import functools
import _sre
# public symbols
__all__ = [
"match", "fullmatch", "search", "sub", "subn", "split",
"findall", "finditer", "compile", "purge", "escape",
"error", "Pattern", "Match", "A", "I", "L", "M", "S", "X", "U",
"ASCII", "IGNORECASE", "LOCALE", "MULTILINE", "DOTALL", "VERBOSE",
"UNICODE", "NOFLAG", "RegexFlag",
]
__version__ = "2.2.1"
@enum.global_enum
@enum._simple_enum(enum.IntFlag, boundary=enum.KEEP)
class RegexFlag:
NOFLAG = 0
ASCII = A = _compiler.SRE_FLAG_ASCII # assume ascii "locale"
IGNORECASE = I = _compiler.SRE_FLAG_IGNORECASE # ignore case
LOCALE = L = _compiler.SRE_FLAG_LOCALE # assume current 8-bit locale
UNICODE = U = _compiler.SRE_FLAG_UNICODE # assume unicode "locale"
MULTILINE = M = _compiler.SRE_FLAG_MULTILINE # make anchors look for newline
DOTALL = S = _compiler.SRE_FLAG_DOTALL # make dot match newline
VERBOSE = X = _compiler.SRE_FLAG_VERBOSE # ignore whitespace and comments
# sre extensions (experimental, don't rely on these)
DEBUG = _compiler.SRE_FLAG_DEBUG # dump pattern after compilation
__str__ = object.__str__
_numeric_repr_ = hex
2000-06-29 05:58:44 -03:00
# sre exception
error = _compiler.error
2000-06-29 05:58:44 -03:00
# --------------------------------------------------------------------
# public interface
def match(pattern, string, flags=0):
"""Try to apply the pattern at the start of the string, returning
a Match object, or None if no match was found."""
return _compile(pattern, flags).match(string)
def fullmatch(pattern, string, flags=0):
"""Try to apply the pattern to all of the string, returning
a Match object, or None if no match was found."""
return _compile(pattern, flags).fullmatch(string)
def search(pattern, string, flags=0):
"""Scan through string looking for a match to the pattern, returning
a Match object, or None if no match was found."""
return _compile(pattern, flags).search(string)
class _ZeroSentinel(int):
pass
_zero_sentinel = _ZeroSentinel()
def sub(pattern, repl, string, *args, count=_zero_sentinel, flags=_zero_sentinel):
"""Return the string obtained by replacing the leftmost
non-overlapping occurrences of the pattern in string by the
replacement repl. repl can be either a string or a callable;
Merged revisions 68116-68119,68121,68123-68127 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r68116 | georg.brandl | 2009-01-01 05:46:51 -0600 (Thu, 01 Jan 2009) | 2 lines #4100: note that element children are not necessarily present on "start" events. ........ r68117 | georg.brandl | 2009-01-01 05:53:55 -0600 (Thu, 01 Jan 2009) | 2 lines #4156: make clear that "protocol" is to be replaced with the protocol name. ........ r68118 | georg.brandl | 2009-01-01 06:00:19 -0600 (Thu, 01 Jan 2009) | 2 lines #4185: clarify escape behavior of replacement strings. ........ r68119 | georg.brandl | 2009-01-01 06:09:40 -0600 (Thu, 01 Jan 2009) | 3 lines #4222: document dis.findlabels() and dis.findlinestarts() and put them into dis.__all__. ........ r68121 | georg.brandl | 2009-01-01 06:43:33 -0600 (Thu, 01 Jan 2009) | 2 lines Point to types module in new module deprecation notice. ........ r68123 | georg.brandl | 2009-01-01 06:52:29 -0600 (Thu, 01 Jan 2009) | 2 lines #4784: ... on three counts ... ........ r68124 | georg.brandl | 2009-01-01 06:53:19 -0600 (Thu, 01 Jan 2009) | 2 lines #4782: Fix markup error that hid load() and loads(). ........ r68125 | georg.brandl | 2009-01-01 07:02:09 -0600 (Thu, 01 Jan 2009) | 2 lines #4776: add data_files and package_dir arguments. ........ r68126 | georg.brandl | 2009-01-01 07:05:13 -0600 (Thu, 01 Jan 2009) | 2 lines Handlers are in the `logging.handlers` module. ........ r68127 | georg.brandl | 2009-01-01 07:14:49 -0600 (Thu, 01 Jan 2009) | 2 lines #4767: Use correct submodules for all MIME classes. ........
2009-01-01 11:05:06 -04:00
if a string, backslash escapes in it are processed. If it is
a callable, it's passed the Match object and must return
a replacement string to be used."""
if args:
if count is not _zero_sentinel:
raise TypeError("sub() got multiple values for argument 'count'")
count, *args = args
if args:
if flags is not _zero_sentinel:
raise TypeError("sub() got multiple values for argument 'flags'")
flags, *args = args
if args:
raise TypeError("sub() takes from 3 to 5 positional arguments "
"but %d were given" % (5 + len(args)))
import warnings
warnings.warn(
"'count' is passed as positional argument",
DeprecationWarning, stacklevel=2
)
return _compile(pattern, flags).sub(repl, string, count)
sub.__text_signature__ = '(pattern, repl, string, count=0, flags=0)'
def subn(pattern, repl, string, *args, count=_zero_sentinel, flags=_zero_sentinel):
"""Return a 2-tuple containing (new_string, number).
new_string is the string obtained by replacing the leftmost
non-overlapping occurrences of the pattern in the source
string by the replacement repl. number is the number of
substitutions that were made. repl can be either a string or a
Merged revisions 68116-68119,68121,68123-68127 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r68116 | georg.brandl | 2009-01-01 05:46:51 -0600 (Thu, 01 Jan 2009) | 2 lines #4100: note that element children are not necessarily present on "start" events. ........ r68117 | georg.brandl | 2009-01-01 05:53:55 -0600 (Thu, 01 Jan 2009) | 2 lines #4156: make clear that "protocol" is to be replaced with the protocol name. ........ r68118 | georg.brandl | 2009-01-01 06:00:19 -0600 (Thu, 01 Jan 2009) | 2 lines #4185: clarify escape behavior of replacement strings. ........ r68119 | georg.brandl | 2009-01-01 06:09:40 -0600 (Thu, 01 Jan 2009) | 3 lines #4222: document dis.findlabels() and dis.findlinestarts() and put them into dis.__all__. ........ r68121 | georg.brandl | 2009-01-01 06:43:33 -0600 (Thu, 01 Jan 2009) | 2 lines Point to types module in new module deprecation notice. ........ r68123 | georg.brandl | 2009-01-01 06:52:29 -0600 (Thu, 01 Jan 2009) | 2 lines #4784: ... on three counts ... ........ r68124 | georg.brandl | 2009-01-01 06:53:19 -0600 (Thu, 01 Jan 2009) | 2 lines #4782: Fix markup error that hid load() and loads(). ........ r68125 | georg.brandl | 2009-01-01 07:02:09 -0600 (Thu, 01 Jan 2009) | 2 lines #4776: add data_files and package_dir arguments. ........ r68126 | georg.brandl | 2009-01-01 07:05:13 -0600 (Thu, 01 Jan 2009) | 2 lines Handlers are in the `logging.handlers` module. ........ r68127 | georg.brandl | 2009-01-01 07:14:49 -0600 (Thu, 01 Jan 2009) | 2 lines #4767: Use correct submodules for all MIME classes. ........
2009-01-01 11:05:06 -04:00
callable; if a string, backslash escapes in it are processed.
If it is a callable, it's passed the Match object and must
return a replacement string to be used."""
if args:
if count is not _zero_sentinel:
raise TypeError("subn() got multiple values for argument 'count'")
count, *args = args
if args:
if flags is not _zero_sentinel:
raise TypeError("subn() got multiple values for argument 'flags'")
flags, *args = args
if args:
raise TypeError("subn() takes from 3 to 5 positional arguments "
"but %d were given" % (5 + len(args)))
import warnings
warnings.warn(
"'count' is passed as positional argument",
DeprecationWarning, stacklevel=2
)
return _compile(pattern, flags).subn(repl, string, count)
subn.__text_signature__ = '(pattern, repl, string, count=0, flags=0)'
def split(pattern, string, *args, maxsplit=_zero_sentinel, flags=_zero_sentinel):
"""Split the source string by the occurrences of the pattern,
returning a list containing the resulting substrings. If
capturing parentheses are used in pattern, then the text of all
groups in the pattern are also returned as part of the resulting
list. If maxsplit is nonzero, at most maxsplit splits occur,
and the remainder of the string is returned as the final element
of the list."""
if args:
if maxsplit is not _zero_sentinel:
raise TypeError("split() got multiple values for argument 'maxsplit'")
maxsplit, *args = args
if args:
if flags is not _zero_sentinel:
raise TypeError("split() got multiple values for argument 'flags'")
flags, *args = args
if args:
raise TypeError("split() takes from 2 to 4 positional arguments "
"but %d were given" % (4 + len(args)))
import warnings
warnings.warn(
"'maxsplit' is passed as positional argument",
DeprecationWarning, stacklevel=2
)
return _compile(pattern, flags).split(string, maxsplit)
split.__text_signature__ = '(pattern, string, maxsplit=0, flags=0)'
def findall(pattern, string, flags=0):
"""Return a list of all non-overlapping matches in the string.
If one or more capturing groups are present in the pattern, return
a list of groups; this will be a list of tuples if the pattern
has more than one group.
Empty matches are included in the result."""
return _compile(pattern, flags).findall(string)
def finditer(pattern, string, flags=0):
"""Return an iterator over all non-overlapping matches in the
string. For each match, the iterator returns a Match object.
Empty matches are included in the result."""
return _compile(pattern, flags).finditer(string)
def compile(pattern, flags=0):
"Compile a regular expression pattern, returning a Pattern object."
return _compile(pattern, flags)
def purge():
2010-08-13 13:27:38 -03:00
"Clear the regular expression caches"
_cache.clear()
_cache2.clear()
_compile_template.cache_clear()
# SPECIAL_CHARS
# closing ')', '}' and ']'
# '-' (a range in character set)
# '&', '~', (extended character set operations)
# '#' (comment) and WHITESPACE (ignored) in verbose mode
_special_chars_map = {i: '\\' + chr(i) for i in b'()[]{}?*+-|^$\\.&~# \t\n\r\v\f'}
2005-09-12 19:50:37 -03:00
def escape(pattern):
"""
Escape special characters in a string.
"""
if isinstance(pattern, str):
return pattern.translate(_special_chars_map)
else:
pattern = str(pattern, 'latin1')
return pattern.translate(_special_chars_map).encode('latin1')
Pattern = type(_compiler.compile('', 0))
Match = type(_compiler.compile('', 0).match(''))
# --------------------------------------------------------------------
# internals
# Use the fact that dict keeps the insertion order.
# _cache2 uses the simple FIFO policy which has better latency.
# _cache uses the LRU policy which has better hit rate.
_cache = {} # LRU
_cache2 = {} # FIFO
_MAXCACHE = 512
_MAXCACHE2 = 256
assert _MAXCACHE2 < _MAXCACHE
def _compile(pattern, flags):
# internal: compile pattern
if isinstance(flags, RegexFlag):
flags = flags.value
try:
return _cache2[type(pattern), pattern, flags]
except KeyError:
pass
key = (type(pattern), pattern, flags)
# Item in _cache should be moved to the end if found.
p = _cache.pop(key, None)
if p is None:
if isinstance(pattern, Pattern):
if flags:
raise ValueError(
"cannot process flags argument with a compiled pattern")
return pattern
if not _compiler.isstring(pattern):
raise TypeError("first argument must be string or compiled pattern")
p = _compiler.compile(pattern, flags)
if flags & DEBUG:
return p
if len(_cache) >= _MAXCACHE:
# Drop the least recently used item.
# next(iter(_cache)) is known to have linear amortized time,
# but it is used here to avoid a dependency from using OrderedDict.
# For the small _MAXCACHE value it doesn't make much of a difference.
try:
del _cache[next(iter(_cache))]
except (StopIteration, RuntimeError, KeyError):
pass
# Append to the end.
_cache[key] = p
if len(_cache2) >= _MAXCACHE2:
# Drop the oldest item.
try:
del _cache2[next(iter(_cache2))]
except (StopIteration, RuntimeError, KeyError):
pass
_cache2[key] = p
return p
@functools.lru_cache(_MAXCACHE)
def _compile_template(pattern, repl):
# internal: compile replacement pattern
return _sre.template(pattern, _parser.parse_template(repl, pattern))
# register myself for pickling
import copyreg
def _pickle(p):
return _compile, (p.pattern, p.flags)
copyreg.pickle(Pattern, _pickle, _compile)
# --------------------------------------------------------------------
# experimental stuff (see python-dev discussions for details)
class Scanner:
def __init__(self, lexicon, flags=0):
from ._constants import BRANCH, SUBPATTERN
if isinstance(flags, RegexFlag):
flags = flags.value
self.lexicon = lexicon
# combine phrases into a compound pattern
p = []
s = _parser.State()
s.flags = flags
for phrase, action in lexicon:
gid = s.opengroup()
p.append(_parser.SubPattern(s, [
(SUBPATTERN, (gid, 0, 0, _parser.parse(phrase, flags))),
]))
s.closegroup(gid, p[-1])
p = _parser.SubPattern(s, [(BRANCH, (None, p))])
self.scanner = _compiler.compile(p)
def scan(self, string):
result = []
append = result.append
match = self.scanner.scanner(string).match
i = 0
while True:
m = match()
if not m:
break
j = m.end()
if i == j:
break
action = self.lexicon[m.lastindex-1][1]
if callable(action):
self.match = m
action = action(self, m.group())
if action is not None:
append(action)
i = j
return result, string[i:]