1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
#
# Secret Labs' Regular Expression Engine
#
# re-compatible interface for the sre matching engine
#
# Copyright (c) 1998-2000 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.
#
# FIXME: change all FIXME's to XXX ;-)
import sre_compile
import sre_parse
import string
# flags
I = IGNORECASE = sre_compile.SRE_FLAG_IGNORECASE
L = LOCALE = sre_compile.SRE_FLAG_LOCALE
M = MULTILINE = sre_compile.SRE_FLAG_MULTILINE
S = DOTALL = sre_compile.SRE_FLAG_DOTALL
X = VERBOSE = sre_compile.SRE_FLAG_VERBOSE
# sre extensions (may or may not be in 1.6/2.0 final)
T = TEMPLATE = sre_compile.SRE_FLAG_TEMPLATE
U = UNICODE = sre_compile.SRE_FLAG_UNICODE
# sre exception
error = sre_compile.error
# --------------------------------------------------------------------
# public interface
# FIXME: add docstrings
def match(pattern, string, flags=0):
return _compile(pattern, flags).match(string)
def search(pattern, string, flags=0):
return _compile(pattern, flags).search(string)
def sub(pattern, repl, string, count=0):
return _compile(pattern).sub(repl, string, count)
def subn(pattern, repl, string, count=0):
return _compile(pattern).subn(repl, string, count)
def split(pattern, string, maxsplit=0):
return _compile(pattern).split(string, maxsplit)
def findall(pattern, string, maxsplit=0):
return _compile(pattern).findall(string, maxsplit)
def compile(pattern, flags=0):
return _compile(pattern, flags)
def purge():
_cache.clear()
def template(pattern, flags=0):
return _compile(pattern, flags|T)
def escape(pattern):
s = list(pattern)
for i in range(len(pattern)):
c = pattern[i]
if not ("a" <= c <= "z" or "A" <= c <= "Z" or "0" <= c <= "9"):
if c == "\000":
s[i] = "\\000"
else:
s[i] = "\\" + c
return _join(s, pattern)
# --------------------------------------------------------------------
# internals
_cache = {}
_MAXCACHE = 100
def _join(seq, sep):
# internal: join into string having the same type as sep
return string.join(seq, sep[:0])
def _compile(pattern, flags=0):
# internal: compile pattern
tp = type(pattern)
if tp not in sre_compile.STRING_TYPES:
return pattern
key = (tp, pattern, flags)
try:
return _cache[key]
except KeyError:
pass
p = sre_compile.compile(pattern, flags)
if len(_cache) >= _MAXCACHE:
_cache.clear()
_cache[key] = p
return p
def _sub(pattern, template, string, count=0):
# internal: pattern.sub implementation hook
return _subn(pattern, template, string, count)[0]
def _subn(pattern, template, string, count=0):
# internal: pattern.subn implementation hook
if callable(template):
filter = template
else:
template = sre_parse.parse_template(template, pattern)
def filter(match, template=template):
return sre_parse.expand_template(template, match)
n = i = 0
s = []
append = s.append
c = pattern.scanner(string)
while not count or n < count:
m = c.search()
if not m:
break
b, e = m.span()
if i < b:
append(string[i:b])
append(filter(m))
i = e
n = n + 1
append(string[i:])
return _join(s, string[:0]), n
def _split(pattern, string, maxsplit=0):
# internal: pattern.split implementation hook
n = i = 0
s = []
append = s.append
extend = s.extend
c = pattern.scanner(string)
g = pattern.groups
while not maxsplit or n < maxsplit:
m = c.search()
if not m:
break
b, e = m.span()
if b == e:
if i >= len(string):
break
continue
append(string[i:b])
if g and b != e:
extend(m.groups())
i = e
n = n + 1
append(string[i:])
return s
# register myself for pickling
import copy_reg
def _pickle(p):
return _compile, (p.pattern, p.flags)
copy_reg.pickle(type(_compile("")), _pickle, _compile)
# --------------------------------------------------------------------
# experimental stuff (see python-dev discussions for details)
class Scanner:
def __init__(self, lexicon):
from sre_constants import BRANCH, SUBPATTERN
self.lexicon = lexicon
# combine phrases into a compound pattern
p = []
s = sre_parse.Pattern()
for phrase, action in lexicon:
p.append(sre_parse.SubPattern(s, [
(SUBPATTERN, (len(p), sre_parse.parse(phrase))),
]))
p = sre_parse.SubPattern(s, [(BRANCH, (None, p))])
s.groups = len(p)
self.scanner = sre_compile.compile(p)
def scan(self, string):
result = []
append = result.append
match = self.scanner.match
i = 0
while 1:
m = match(string, i)
if not m:
break
j = m.end()
if i == j:
break
action = self.lexicon[m.lastindex][1]
if callable(action):
self.match = match
action = action(self, m.group())
if action is not None:
append(action)
i = j
return result, string[i:]
|
