291 lines
7.6 KiB
Python
291 lines
7.6 KiB
Python
#!/usr/bin/env python
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# -*- mode: python -*-
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import sys
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import string
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from pcre import *
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#
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# First, the public part of the interface:
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#
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# pcre.error and re.error should be the same, since exceptions can be
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# raised from either module.
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# compilation flags
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I = IGNORECASE
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L = LOCALE
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M = MULTILINE
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S = DOTALL
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X = VERBOSE
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#
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#
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#
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_cache = {}
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_MAXCACHE = 20
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def _cachecompile(pattern, flags=0):
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key = (pattern, flags)
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try:
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return _cache[key]
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except KeyError:
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pass
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value = compile(pattern, flags)
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if len(_cache) >= _MAXCACHE:
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_cache.clear()
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_cache[key] = value
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return value
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def match(pattern, string, flags=0):
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return _cachecompile(pattern, flags).match(string)
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def search(pattern, string, flags=0):
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return _cachecompile(pattern, flags).search(string)
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def sub(pattern, repl, string, count=0):
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if type(pattern) == type(''):
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pattern = _cachecompile(pattern)
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return pattern.sub(repl, string, count)
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def subn(pattern, repl, string, count=0):
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if type(pattern) == type(''):
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pattern = _cachecompile(pattern)
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return pattern.subn(repl, string, count)
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def split(pattern, string, maxsplit=0):
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if type(pattern) == type(''):
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pattern = _cachecompile(pattern)
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return pattern.split(string, maxsplit)
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def escape(pattern):
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"Escape all non-alphanumeric characters in pattern."
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result = []
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alphanum=string.letters+'_'+string.digits
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for char in pattern:
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if char not in alphanum:
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result.append('\\')
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result.append(char)
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return string.join(result, '')
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def compile(pattern, flags=0):
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"Compile a regular expression pattern, returning a RegexObject."
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groupindex={}
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code=pcre_compile(pattern, flags, groupindex)
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return RegexObject(pattern, flags, code, groupindex)
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#
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# Class definitions
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#
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class RegexObject:
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def __init__(self, pattern, flags, code, groupindex):
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self.code = code
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self.flags = flags
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self.pattern = pattern
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self.groupindex = groupindex
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def search(self, string, pos=0, endpos=None):
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"""Scan through string looking for a match to the pattern, returning
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a MatchObject instance, or None if no match was found."""
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if endpos is None or endpos>len(string):
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endpos=len(string)
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if endpos<pos: endpos=pos
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regs = self.code.match(string, pos, endpos, 0)
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if regs is None:
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return None
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self._num_regs=len(regs)
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return MatchObject(self,
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string,
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pos, endpos,
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regs)
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def match(self, string, pos=0, endpos=None):
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"""Try to apply the pattern at the start of the string, returning
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a MatchObject instance, or None if no match was found."""
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if endpos is None or endpos>len(string):
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endpos=len(string)
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if endpos<pos: endpos=pos
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regs = self.code.match(string, pos, endpos, ANCHORED)
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if regs is None:
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return None
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self._num_regs=len(regs)
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return MatchObject(self,
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string,
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pos, endpos,
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regs)
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def sub(self, repl, string, count=0):
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"""Return the string obtained by replacing the leftmost
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non-overlapping occurrences of the pattern in string by the
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replacement repl"""
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return self.subn(repl, string, count)[0]
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def subn(self, repl, source, count=0):
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"""Return a 2-tuple containing (new_string, number).
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new_string is the string obtained by replacing the leftmost
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non-overlapping occurrences of the pattern in string by the
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replacement repl. number is the number of substitutions that
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were made."""
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if count < 0:
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raise error, "negative substitution count"
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if count == 0:
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import sys
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count = sys.maxint
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if type(repl) == type(''):
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if '\\' in repl:
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repl = lambda m, r=repl: pcre_expand(m, r)
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else:
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repl = lambda m, r=repl: r
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n = 0 # Number of matches
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pos = 0 # Where to start searching
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lastmatch = -1 # End of last match
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results = [] # Substrings making up the result
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end = len(source)
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while n < count and pos <= end:
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m = self.search(source, pos)
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if not m:
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break
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i, j = m.span(0)
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if i == j == lastmatch:
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# Empty match adjacent to previous match
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pos = pos + 1
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results.append(source[lastmatch:pos])
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continue
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if pos < i:
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results.append(source[pos:i])
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results.append(repl(m))
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pos = lastmatch = j
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if i == j:
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# Last match was empty; don't try here again
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pos = pos + 1
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results.append(source[lastmatch:pos])
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n = n + 1
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results.append(source[pos:])
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return (string.join(results, ''), n)
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def split(self, source, maxsplit=0):
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"""Split \var{string} by the occurrences of the pattern,
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returning a list containing the resulting substrings."""
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if maxsplit < 0:
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raise error, "negative split count"
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if maxsplit == 0:
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import sys
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maxsplit = sys.maxint
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n = 0
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pos = 0
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lastmatch = 0
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results = []
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end = len(source)
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while n < maxsplit:
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m = self.search(source, pos)
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if not m:
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break
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i, j = m.span(0)
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if i == j:
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# Empty match
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if pos >= end:
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break
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pos = pos+1
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continue
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results.append(source[lastmatch:i])
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g = m.groups()
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if g:
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if type(g)==type( "" ): g = [g]
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results[len(results):] = list(g)
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pos = lastmatch = j
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results.append(source[lastmatch:])
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return results
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# The following 3 functions were contributed by Mike Fletcher, and
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# allow pickling and unpickling of RegexObject instances.
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def __getinitargs__(self):
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return (None,None,None,None) # any 4 elements, to work around
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# problems with the
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# pickle/cPickle modules not yet
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# ignoring the __init__ function
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def __getstate__(self):
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return self.pattern, self.flags, self.groupindex
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def __setstate__(self, statetuple):
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self.pattern = statetuple[0]
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self.flags = statetuple[1]
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self.groupindex = statetuple[2]
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self.code = apply(pcre_compile, statetuple)
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class MatchObject:
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def __init__(self, re, string, pos, endpos, regs):
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self.re = re
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self.string = string
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self.pos = pos
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self.endpos = endpos
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self.regs = regs
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def start(self, g = 0):
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"Return the start of the substring matched by group g"
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if type(g) == type(''):
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try:
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g = self.re.groupindex[g]
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except (KeyError, TypeError):
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raise IndexError, ('group "' + g + '" is undefined')
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return self.regs[g][0]
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def end(self, g = 0):
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"Return the end of the substring matched by group g"
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if type(g) == type(''):
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try:
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g = self.re.groupindex[g]
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except (KeyError, TypeError):
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raise IndexError, ('group "' + g + '" is undefined')
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return self.regs[g][1]
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def span(self, g = 0):
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"""Return a tuple containing the start,end of the substring
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matched by group g"""
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if type(g) == type(''):
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try:
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g = self.re.groupindex[g]
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except (KeyError, TypeError):
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raise IndexError, ('group "' + g + '" is undefined')
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return self.regs[g]
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def groups(self):
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"Return a tuple containing all subgroups of the match object"
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# If _num_regs==1, we don't want to call self.group with an
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# empty tuple.
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if self.re._num_regs == 1: return ()
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return apply(self.group, tuple(range(1, self.re._num_regs) ) )
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def group(self, *groups):
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"Return one or more groups of the match."
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if len(groups) == 0:
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groups = (0,)
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result = []
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for g in groups:
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if type(g) == type(''):
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try:
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g = self.re.groupindex[g]
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except (KeyError, TypeError):
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raise IndexError, ('group "' + g + '" is undefined')
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if len(self.regs)<=g: raise IndexError, ('group "' + str(g) + '" is undefined')
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elif (self.regs[g][0] == -1) or (self.regs[g][1] == -1):
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result.append(None)
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else:
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result.append(self.string[self.regs[g][0]:self.regs[g][1]])
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if len(result) > 1:
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return tuple(result)
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elif len(result) == 1:
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return result[0]
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else:
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return ()
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