import re
class MultiRegex(object):
flags = re.DOTALL
regexes = ()
def __init__(self):
'''
compile a disjunction of regexes, in order
'''
self._regex = re.compile("|".join(self.regexes), self.flags)
def sub(self, s):
return self._regex.sub(self._sub, s)
def _sub(self, mo):
'''
determine which partial regex matched, and
dispatch on self accordingly.
'''
for k,v in mo.groupdict().iteritems():
if v:
sub = getattr(self, k)
if callable(sub):
return sub(mo)
return sub
raise AttributeError, \
'nothing captured, matching sub-regex could not be identified'
class TrivialExample(MultiRegex):
regexes = (
r'(?P<lower>[a-z]{2,})',
r'(?P<upper>[A-Z]{2,})',
r'(?P<mixed>[A-Za-z]+)'
)
def lower(self, mo):
return 'lower:' + mo.group()
upper = lambda self, mo: 'upper:' + mo.group()
mixed = 'stuff'
class TrivialExample2(TrivialExample):
'''
this illustrates that the order of regexes is important
'''
regexes = (
r'(?P<mixed>[a-zA-Z]+)',
r'(?P<lower>[a-z]{2,})',
r'(?P<upper>[A-Z]{2,})'
)
a = 'That cake was AWESOME, dude!'
print TrivialExample().sub(a)
print TrivialExample2().sub(a)
'''
produces:
stuff lower:cake lower:was upper:AWESOME, lower:dude!
stuff stuff stuff stuff, stuff!
'''
