blob: d772979f91e1af4f9a636c75f56a789b473376bb [file] [log] [blame]
Guido van Rossum7627c0d2000-03-31 14:58:54 +00001#
2# Secret Labs' Regular Expression Engine
Guido van Rossum7627c0d2000-03-31 14:58:54 +00003#
4# re-compatible interface for the sre matching engine
5#
Fredrik Lundh770617b2001-01-14 15:06:11 +00006# Copyright (c) 1998-2001 by Secret Labs AB. All rights reserved.
Guido van Rossum7627c0d2000-03-31 14:58:54 +00007#
Fredrik Lundh29c4ba92000-08-01 18:20:07 +00008# This version of the SRE library can be redistributed under CNRI's
9# Python 1.6 license. For any other use, please contact Secret Labs
10# AB (info@pythonware.com).
11#
Guido van Rossum7627c0d2000-03-31 14:58:54 +000012# Portions of this engine have been developed in cooperation with
Fredrik Lundh29c4ba92000-08-01 18:20:07 +000013# CNRI. Hewlett-Packard provided funding for 1.6 integration and
Guido van Rossum7627c0d2000-03-31 14:58:54 +000014# other compatibility work.
15#
16
Fred Drake9f5b8222001-09-04 19:20:06 +000017r"""Support for regular expressions (RE).
Fred Drakeb8f22742001-09-04 19:10:20 +000018
19This module provides regular expression matching operations similar to
Fredrik Lundhdac58492001-10-21 21:48:30 +000020those found in Perl. It supports both 8-bit and Unicode strings; both
21the pattern and the strings being processed can contain null bytes and
22characters outside the US ASCII range.
Fred Drakeb8f22742001-09-04 19:10:20 +000023
Fredrik Lundhdac58492001-10-21 21:48:30 +000024Regular expressions can contain both special and ordinary characters.
25Most ordinary characters, like "A", "a", or "0", are the simplest
26regular expressions; they simply match themselves. You can
Fred Drakeb8f22742001-09-04 19:10:20 +000027concatenate ordinary characters, so last matches the string 'last'.
28
29The special characters are:
30 "." Matches any character except a newline.
31 "^" Matches the start of the string.
Georg Brandl86def6c2008-01-21 20:36:10 +000032 "$" Matches the end of the string or just before the newline at
33 the end of the string.
Fred Drakeb8f22742001-09-04 19:10:20 +000034 "*" Matches 0 or more (greedy) repetitions of the preceding RE.
35 Greedy means that it will match as many repetitions as possible.
36 "+" Matches 1 or more (greedy) repetitions of the preceding RE.
37 "?" Matches 0 or 1 (greedy) of the preceding RE.
38 *?,+?,?? Non-greedy versions of the previous three special characters.
39 {m,n} Matches from m to n repetitions of the preceding RE.
40 {m,n}? Non-greedy version of the above.
Christian Heimesaf98da12008-01-27 15:18:18 +000041 "\\" Either escapes special characters or signals a special sequence.
Fred Drakeb8f22742001-09-04 19:10:20 +000042 [] Indicates a set of characters.
43 A "^" as the first character indicates a complementing set.
44 "|" A|B, creates an RE that will match either A or B.
45 (...) Matches the RE inside the parentheses.
46 The contents can be retrieved or matched later in the string.
Antoine Pitroufd036452008-08-19 17:56:33 +000047 (?aiLmsux) Set the A, I, L, M, S, U, or X flag for the RE (see below).
Fred Drakeb8f22742001-09-04 19:10:20 +000048 (?:...) Non-grouping version of regular parentheses.
49 (?P<name>...) The substring matched by the group is accessible by name.
50 (?P=name) Matches the text matched earlier by the group named name.
51 (?#...) A comment; ignored.
52 (?=...) Matches if ... matches next, but doesn't consume the string.
53 (?!...) Matches if ... doesn't match next.
Christian Heimesaf98da12008-01-27 15:18:18 +000054 (?<=...) Matches if preceded by ... (must be fixed length).
55 (?<!...) Matches if not preceded by ... (must be fixed length).
56 (?(id/name)yes|no) Matches yes pattern if the group with id/name matched,
57 the (optional) no pattern otherwise.
Fred Drakeb8f22742001-09-04 19:10:20 +000058
59The special sequences consist of "\\" and a character from the list
Fredrik Lundhdac58492001-10-21 21:48:30 +000060below. If the ordinary character is not on the list, then the
Fred Drakeb8f22742001-09-04 19:10:20 +000061resulting RE will match the second character.
Fred Drake9f5b8222001-09-04 19:20:06 +000062 \number Matches the contents of the group of the same number.
63 \A Matches only at the start of the string.
64 \Z Matches only at the end of the string.
65 \b Matches the empty string, but only at the start or end of a word.
66 \B Matches the empty string, but not at the start or end of a word.
Antoine Pitroufd036452008-08-19 17:56:33 +000067 \d Matches any decimal digit; equivalent to the set [0-9] in
68 bytes patterns or string patterns with the ASCII flag.
69 In string patterns without the ASCII flag, it will match the whole
70 range of Unicode digits.
71 \D Matches any non-digit character; equivalent to [^\d].
Ezio Melottie9900922012-04-29 08:23:25 +030072 \s Matches any whitespace character; equivalent to [ \t\n\r\f\v] in
73 bytes patterns or string patterns with the ASCII flag.
74 In string patterns without the ASCII flag, it will match the whole
75 range of Unicode whitespace characters.
Ezio Melotti38992832012-04-29 13:35:55 +030076 \S Matches any non-whitespace character; equivalent to [^\s].
Antoine Pitroufd036452008-08-19 17:56:33 +000077 \w Matches any alphanumeric character; equivalent to [a-zA-Z0-9_]
78 in bytes patterns or string patterns with the ASCII flag.
79 In string patterns without the ASCII flag, it will match the
80 range of Unicode alphanumeric characters (letters plus digits
81 plus underscore).
Fred Drakeb8f22742001-09-04 19:10:20 +000082 With LOCALE, it will match the set [0-9_] plus characters defined
83 as letters for the current locale.
Fred Drake9f5b8222001-09-04 19:20:06 +000084 \W Matches the complement of \w.
85 \\ Matches a literal backslash.
Fred Drakeb8f22742001-09-04 19:10:20 +000086
87This module exports the following functions:
Serhiy Storchaka32eddc12013-11-23 23:20:30 +020088 match Match a regular expression pattern to the beginning of a string.
89 fullmatch Match a regular expression pattern to all of a string.
90 search Search a string for the presence of a pattern.
91 sub Substitute occurrences of a pattern found in a string.
92 subn Same as sub, but also return the number of substitutions made.
93 split Split a string by the occurrences of a pattern.
94 findall Find all occurrences of a pattern in a string.
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +030095 finditer Return an iterator yielding a Match object for each match.
96 compile Compile a pattern into a Pattern object.
Serhiy Storchaka32eddc12013-11-23 23:20:30 +020097 purge Clear the regular expression cache.
98 escape Backslash all non-alphanumerics in a string.
Fred Drakeb8f22742001-09-04 19:10:20 +000099
100Some of the functions in this module takes flags as optional parameters:
Antoine Pitroufd036452008-08-19 17:56:33 +0000101 A ASCII For string patterns, make \w, \W, \b, \B, \d, \D
102 match the corresponding ASCII character categories
103 (rather than the whole Unicode categories, which is the
104 default).
105 For bytes patterns, this flag is the only available
106 behaviour and needn't be specified.
Fred Drakeb8f22742001-09-04 19:10:20 +0000107 I IGNORECASE Perform case-insensitive matching.
108 L LOCALE Make \w, \W, \b, \B, dependent on the current locale.
Georg Brandl86def6c2008-01-21 20:36:10 +0000109 M MULTILINE "^" matches the beginning of lines (after a newline)
110 as well as the string.
111 "$" matches the end of lines (before a newline) as well
112 as the end of the string.
Fred Drakeb8f22742001-09-04 19:10:20 +0000113 S DOTALL "." matches any character at all, including the newline.
114 X VERBOSE Ignore whitespace and comments for nicer looking RE's.
Antoine Pitroufd036452008-08-19 17:56:33 +0000115 U UNICODE For compatibility only. Ignored for string patterns (it
116 is the default), and forbidden for bytes patterns.
Fred Drakeb8f22742001-09-04 19:10:20 +0000117
118This module also defines an exception 'error'.
119
120"""
Fredrik Lundh21009b92001-09-18 18:47:09 +0000121
Victor Stinnerfb6a6592016-11-14 12:35:55 +0100122import enum
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000123import sre_compile
Fredrik Lundh436c3d582000-06-29 08:58:44 +0000124import sre_parse
Raymond Hettinger5820f3a2016-09-18 20:17:21 -0700125import functools
Serhiy Storchakacf7b1ca2014-10-31 01:34:45 +0200126try:
127 import _locale
128except ImportError:
129 _locale = None
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000130
Serhiy Storchaka114454e2017-09-26 19:47:36 +0300131# try _collections first to reduce startup cost
132try:
133 from _collections import OrderedDict
134except ImportError:
135 from collections import OrderedDict
136
137
Fredrik Lundhf2989b22001-02-18 12:05:16 +0000138# public symbols
Serhiy Storchakabe4de522014-09-28 15:36:18 +0300139__all__ = [
140 "match", "fullmatch", "search", "sub", "subn", "split",
141 "findall", "finditer", "compile", "purge", "template", "escape",
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300142 "error", "Pattern", "Match", "A", "I", "L", "M", "S", "X", "U",
Serhiy Storchakabe4de522014-09-28 15:36:18 +0300143 "ASCII", "IGNORECASE", "LOCALE", "MULTILINE", "DOTALL", "VERBOSE",
144 "UNICODE",
145]
Fredrik Lundhf2989b22001-02-18 12:05:16 +0000146
Fredrik Lundhbec95b92001-10-21 16:47:57 +0000147__version__ = "2.2.1"
Fredrik Lundhb25e1ad2001-03-22 15:50:10 +0000148
Victor Stinnerfb6a6592016-11-14 12:35:55 +0100149class RegexFlag(enum.IntFlag):
150 ASCII = sre_compile.SRE_FLAG_ASCII # assume ascii "locale"
151 IGNORECASE = sre_compile.SRE_FLAG_IGNORECASE # ignore case
152 LOCALE = sre_compile.SRE_FLAG_LOCALE # assume current 8-bit locale
153 UNICODE = sre_compile.SRE_FLAG_UNICODE # assume unicode "locale"
154 MULTILINE = sre_compile.SRE_FLAG_MULTILINE # make anchors look for newline
155 DOTALL = sre_compile.SRE_FLAG_DOTALL # make dot match newline
156 VERBOSE = sre_compile.SRE_FLAG_VERBOSE # ignore whitespace and comments
157 A = ASCII
158 I = IGNORECASE
159 L = LOCALE
160 U = UNICODE
161 M = MULTILINE
162 S = DOTALL
163 X = VERBOSE
164 # sre extensions (experimental, don't rely on these)
165 TEMPLATE = sre_compile.SRE_FLAG_TEMPLATE # disable backtracking
166 T = TEMPLATE
167 DEBUG = sre_compile.SRE_FLAG_DEBUG # dump pattern after compilation
168globals().update(RegexFlag.__members__)
Fredrik Lundh436c3d582000-06-29 08:58:44 +0000169
170# sre exception
Fredrik Lundhbe2211e2000-06-29 16:57:40 +0000171error = sre_compile.error
Fredrik Lundh436c3d582000-06-29 08:58:44 +0000172
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000173# --------------------------------------------------------------------
174# public interface
175
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000176def match(pattern, string, flags=0):
Fredrik Lundh770617b2001-01-14 15:06:11 +0000177 """Try to apply the pattern at the start of the string, returning
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300178 a Match object, or None if no match was found."""
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000179 return _compile(pattern, flags).match(string)
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000180
Serhiy Storchaka32eddc12013-11-23 23:20:30 +0200181def fullmatch(pattern, string, flags=0):
182 """Try to apply the pattern to all of the string, returning
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300183 a Match object, or None if no match was found."""
Serhiy Storchaka32eddc12013-11-23 23:20:30 +0200184 return _compile(pattern, flags).fullmatch(string)
185
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000186def search(pattern, string, flags=0):
Fredrik Lundh770617b2001-01-14 15:06:11 +0000187 """Scan through string looking for a match to the pattern, returning
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300188 a Match object, or None if no match was found."""
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000189 return _compile(pattern, flags).search(string)
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000190
Gregory P. Smithccc5ae72009-03-02 05:21:55 +0000191def sub(pattern, repl, string, count=0, flags=0):
Fredrik Lundh770617b2001-01-14 15:06:11 +0000192 """Return the string obtained by replacing the leftmost
193 non-overlapping occurrences of the pattern in string by the
Andrew M. Kuchling43ab0cd2004-08-07 17:41:54 +0000194 replacement repl. repl can be either a string or a callable;
Benjamin Peterson75edad02009-01-01 15:05:06 +0000195 if a string, backslash escapes in it are processed. If it is
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300196 a callable, it's passed the Match object and must return
Andrew M. Kuchling43ab0cd2004-08-07 17:41:54 +0000197 a replacement string to be used."""
Gregory P. Smithccc5ae72009-03-02 05:21:55 +0000198 return _compile(pattern, flags).sub(repl, string, count)
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000199
Gregory P. Smithccc5ae72009-03-02 05:21:55 +0000200def subn(pattern, repl, string, count=0, flags=0):
Fredrik Lundh770617b2001-01-14 15:06:11 +0000201 """Return a 2-tuple containing (new_string, number).
202 new_string is the string obtained by replacing the leftmost
203 non-overlapping occurrences of the pattern in the source
204 string by the replacement repl. number is the number of
Andrew M. Kuchling43ab0cd2004-08-07 17:41:54 +0000205 substitutions that were made. repl can be either a string or a
Benjamin Peterson75edad02009-01-01 15:05:06 +0000206 callable; if a string, backslash escapes in it are processed.
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300207 If it is a callable, it's passed the Match object and must
Andrew M. Kuchling43ab0cd2004-08-07 17:41:54 +0000208 return a replacement string to be used."""
Gregory P. Smithccc5ae72009-03-02 05:21:55 +0000209 return _compile(pattern, flags).subn(repl, string, count)
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000210
Gregory P. Smithccc5ae72009-03-02 05:21:55 +0000211def split(pattern, string, maxsplit=0, flags=0):
Fredrik Lundh770617b2001-01-14 15:06:11 +0000212 """Split the source string by the occurrences of the pattern,
Georg Brandle144c742012-03-10 09:26:53 +0100213 returning a list containing the resulting substrings. If
214 capturing parentheses are used in pattern, then the text of all
215 groups in the pattern are also returned as part of the resulting
216 list. If maxsplit is nonzero, at most maxsplit splits occur,
217 and the remainder of the string is returned as the final element
218 of the list."""
Gregory P. Smithccc5ae72009-03-02 05:21:55 +0000219 return _compile(pattern, flags).split(string, maxsplit)
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000220
Raymond Hettinger596ba4d2004-09-24 03:41:05 +0000221def findall(pattern, string, flags=0):
Fredrik Lundh770617b2001-01-14 15:06:11 +0000222 """Return a list of all non-overlapping matches in the string.
223
Georg Brandle144c742012-03-10 09:26:53 +0100224 If one or more capturing groups are present in the pattern, return
225 a list of groups; this will be a list of tuples if the pattern
Fredrik Lundh770617b2001-01-14 15:06:11 +0000226 has more than one group.
227
228 Empty matches are included in the result."""
Raymond Hettinger596ba4d2004-09-24 03:41:05 +0000229 return _compile(pattern, flags).findall(string)
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000230
Serhiy Storchakabe4de522014-09-28 15:36:18 +0300231def finditer(pattern, string, flags=0):
232 """Return an iterator over all non-overlapping matches in the
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300233 string. For each match, the iterator returns a Match object.
Fredrik Lundh703ce812001-10-24 22:16:30 +0000234
Serhiy Storchakabe4de522014-09-28 15:36:18 +0300235 Empty matches are included in the result."""
236 return _compile(pattern, flags).finditer(string)
Fredrik Lundh703ce812001-10-24 22:16:30 +0000237
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000238def compile(pattern, flags=0):
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300239 "Compile a regular expression pattern, returning a Pattern object."
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000240 return _compile(pattern, flags)
241
Fredrik Lundh8a3ebf82000-07-23 21:46:17 +0000242def purge():
Antoine Pitrou3060c452010-08-13 16:27:38 +0000243 "Clear the regular expression caches"
Serhiy Storchaka0f606a62013-03-16 22:52:09 +0200244 _cache.clear()
Raymond Hettinger5820f3a2016-09-18 20:17:21 -0700245 _compile_repl.cache_clear()
Fredrik Lundh8a3ebf82000-07-23 21:46:17 +0000246
Fredrik Lundh436c3d582000-06-29 08:58:44 +0000247def template(pattern, flags=0):
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300248 "Compile a template pattern, returning a Pattern object"
Fredrik Lundh436c3d582000-06-29 08:58:44 +0000249 return _compile(pattern, flags|T)
250
Serhiy Storchaka59083002017-04-13 21:06:43 +0300251# SPECIAL_CHARS
252# closing ')', '}' and ']'
253# '-' (a range in character set)
254# '#' (comment) and WHITESPACE (ignored) in verbose mode
255_special_chars_map = {i: '\\' + chr(i) for i in b'()[]{}?*+-|^$\\.# \t\n\r\v\f'}
Raymond Hettingerebb7f302005-09-12 22:50:37 +0000256
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000257def escape(pattern):
Ezio Melotti88fdeb42011-04-10 12:59:16 +0300258 """
Serhiy Storchaka59083002017-04-13 21:06:43 +0300259 Escape special characters in a string.
Ezio Melotti88fdeb42011-04-10 12:59:16 +0300260 """
Guido van Rossum698280d2008-09-10 17:44:35 +0000261 if isinstance(pattern, str):
Serhiy Storchaka59083002017-04-13 21:06:43 +0300262 return pattern.translate(_special_chars_map)
Guido van Rossum698280d2008-09-10 17:44:35 +0000263 else:
Serhiy Storchaka59083002017-04-13 21:06:43 +0300264 pattern = str(pattern, 'latin1')
265 return pattern.translate(_special_chars_map).encode('latin1')
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000266
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300267Pattern = type(sre_compile.compile('', 0))
268Match = type(sre_compile.compile('', 0).match(''))
269
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000270# --------------------------------------------------------------------
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000271# internals
Guido van Rossum7627c0d2000-03-31 14:58:54 +0000272
Serhiy Storchaka114454e2017-09-26 19:47:36 +0300273_cache = OrderedDict()
Serhiy Storchaka0f606a62013-03-16 22:52:09 +0200274
Serhiy Storchaka0f606a62013-03-16 22:52:09 +0200275_MAXCACHE = 512
Raymond Hettingerd9e8cc62010-08-14 21:17:48 +0000276def _compile(pattern, flags):
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000277 # internal: compile pattern
Serhiy Storchaka4d75a012014-09-29 18:13:02 +0300278 try:
Serhiy Storchaka898ff032017-05-05 08:53:40 +0300279 return _cache[type(pattern), pattern, flags]
Serhiy Storchaka4d75a012014-09-29 18:13:02 +0300280 except KeyError:
281 pass
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300282 if isinstance(pattern, Pattern):
Christian Heimes5fb7c2a2007-12-24 08:52:31 +0000283 if flags:
Guido van Rossum698280d2008-09-10 17:44:35 +0000284 raise ValueError(
Serhiy Storchaka632a77e2015-03-25 21:03:47 +0200285 "cannot process flags argument with a compiled pattern")
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000286 return pattern
Just van Rossum74902502003-07-02 21:37:16 +0000287 if not sre_compile.isstring(pattern):
Collin Winterce36ad82007-08-30 01:19:48 +0000288 raise TypeError("first argument must be string or compiled pattern")
Serhiy Storchaka0f606a62013-03-16 22:52:09 +0200289 p = sre_compile.compile(pattern, flags)
Serhiy Storchaka4d75a012014-09-29 18:13:02 +0300290 if not (flags & DEBUG):
Antoine Pitroud2cc7432014-02-03 20:59:59 +0100291 if len(_cache) >= _MAXCACHE:
Serhiy Storchaka114454e2017-09-26 19:47:36 +0300292 try:
Barry Warsawdb50ba72017-09-27 11:12:30 -0400293 _cache.popitem(last=False)
Serhiy Storchaka114454e2017-09-26 19:47:36 +0300294 except KeyError:
295 pass
Serhiy Storchaka898ff032017-05-05 08:53:40 +0300296 _cache[type(pattern), pattern, flags] = p
Serhiy Storchaka0f606a62013-03-16 22:52:09 +0200297 return p
Jeremy Hyltonb1aa1952000-06-01 17:39:12 +0000298
Raymond Hettinger5820f3a2016-09-18 20:17:21 -0700299@functools.lru_cache(_MAXCACHE)
Raymond Hettingerd9e8cc62010-08-14 21:17:48 +0000300def _compile_repl(repl, pattern):
Fredrik Lundhb25e1ad2001-03-22 15:50:10 +0000301 # internal: compile replacement pattern
Raymond Hettinger5820f3a2016-09-18 20:17:21 -0700302 return sre_parse.parse_template(repl, pattern)
Fredrik Lundhb25e1ad2001-03-22 15:50:10 +0000303
Fredrik Lundh5644b7f2000-09-21 17:03:25 +0000304def _expand(pattern, match, template):
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300305 # internal: Match.expand implementation hook
Fredrik Lundh5644b7f2000-09-21 17:03:25 +0000306 template = sre_parse.parse_template(template, pattern)
307 return sre_parse.expand_template(template, match)
308
Fredrik Lundhbec95b92001-10-21 16:47:57 +0000309def _subx(pattern, template):
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300310 # internal: Pattern.sub/subn implementation helper
Fredrik Lundhdac58492001-10-21 21:48:30 +0000311 template = _compile_repl(template, pattern)
312 if not template[0] and len(template[1]) == 1:
Fredrik Lundhbec95b92001-10-21 16:47:57 +0000313 # literal replacement
Fredrik Lundhdac58492001-10-21 21:48:30 +0000314 return template[1][0]
315 def filter(match, template=template):
316 return sre_parse.expand_template(template, match)
317 return filter
Fredrik Lundh0640e112000-06-30 13:55:15 +0000318
319# register myself for pickling
320
Alexandre Vassalottif7fa63d2008-05-11 08:55:36 +0000321import copyreg
Fredrik Lundh0640e112000-06-30 13:55:15 +0000322
323def _pickle(p):
324 return _compile, (p.pattern, p.flags)
325
Serhiy Storchaka0b5e61d2017-10-04 20:09:49 +0300326copyreg.pickle(Pattern, _pickle, _compile)
Fredrik Lundh7cafe4d2000-07-02 17:33:27 +0000327
328# --------------------------------------------------------------------
329# experimental stuff (see python-dev discussions for details)
330
331class Scanner:
Fredrik Lundh1296a8d2001-10-21 18:04:11 +0000332 def __init__(self, lexicon, flags=0):
Fredrik Lundh29c4ba92000-08-01 18:20:07 +0000333 from sre_constants import BRANCH, SUBPATTERN
Fredrik Lundh7cafe4d2000-07-02 17:33:27 +0000334 self.lexicon = lexicon
Fredrik Lundh8a3ebf82000-07-23 21:46:17 +0000335 # combine phrases into a compound pattern
Fredrik Lundh7cafe4d2000-07-02 17:33:27 +0000336 p = []
Fredrik Lundh8a3ebf82000-07-23 21:46:17 +0000337 s = sre_parse.Pattern()
Fredrik Lundh1296a8d2001-10-21 18:04:11 +0000338 s.flags = flags
Fredrik Lundh7cafe4d2000-07-02 17:33:27 +0000339 for phrase, action in lexicon:
Serhiy Storchaka4eea62f2015-02-21 10:07:35 +0200340 gid = s.opengroup()
Fredrik Lundh8a3ebf82000-07-23 21:46:17 +0000341 p.append(sre_parse.SubPattern(s, [
Serhiy Storchakabe9a4e52016-09-10 00:57:55 +0300342 (SUBPATTERN, (gid, 0, 0, sre_parse.parse(phrase, flags))),
Fredrik Lundh8a3ebf82000-07-23 21:46:17 +0000343 ]))
Serhiy Storchaka4eea62f2015-02-21 10:07:35 +0200344 s.closegroup(gid, p[-1])
Fredrik Lundh8a3ebf82000-07-23 21:46:17 +0000345 p = sre_parse.SubPattern(s, [(BRANCH, (None, p))])
Fredrik Lundh8a3ebf82000-07-23 21:46:17 +0000346 self.scanner = sre_compile.compile(p)
Fredrik Lundh7cafe4d2000-07-02 17:33:27 +0000347 def scan(self, string):
348 result = []
349 append = result.append
Fredrik Lundh1296a8d2001-10-21 18:04:11 +0000350 match = self.scanner.scanner(string).match
Fredrik Lundh7cafe4d2000-07-02 17:33:27 +0000351 i = 0
Serhiy Storchakaab140882014-11-11 21:13:28 +0200352 while True:
Fredrik Lundh1296a8d2001-10-21 18:04:11 +0000353 m = match()
Fredrik Lundh7cafe4d2000-07-02 17:33:27 +0000354 if not m:
355 break
356 j = m.end()
357 if i == j:
358 break
Fredrik Lundh1296a8d2001-10-21 18:04:11 +0000359 action = self.lexicon[m.lastindex-1][1]
Florent Xicluna5d1155c2011-10-28 14:45:05 +0200360 if callable(action):
Fredrik Lundh770617b2001-01-14 15:06:11 +0000361 self.match = m
Fredrik Lundh7cafe4d2000-07-02 17:33:27 +0000362 action = action(self, m.group())
363 if action is not None:
364 append(action)
365 i = j
366 return result, string[i:]