[Python] Alternative to the `match = re.match(); if match: ...` idiom?

If you want to check if something matches a regex, if so, print the first group, you do..

import re
match = re.match("(\d+)g", "123g")
if match is not None:
print match.group(1)


This is completely pedantic, but the intermediate match variable is a bit annoying..

Languages like Perl do this by creating new $1..$9 variables for match groups, like..

if($blah ~= /(\d+)g/){
print $1
}


From this reddit comment,

with re_context.match('^blah', s) as match:
if match:
...
else:
...


..which I thought was an interesting idea, so I wrote a simple implementation of it:

#!/usr/bin/env python2.6
import re

class SRE_Match_Wrapper:
def __init__(self, match):
self.match = match

def __exit__(self, type, value, tb):
pass

def __enter__(self):
return self.match

def __getattr__(self, name):
if name == "__exit__":
return self.__exit__
elif name == "__enter__":
return self.__name__
else:
return getattr(self.match, name)

def rematch(pattern, inp):
matcher = re.compile(pattern)
x = SRE_Match_Wrapper(matcher.match(inp))
return x
return match

if __name__ == '__main__':
# Example:
with rematch("(\d+)g", "123g") as m:
if m:
print(m.group(1))

with rematch("(\d+)g", "123") as m:
if m:
print(m.group(1))


(This functionality could theoretically be patched into the _sre.SRE_Match object)

It would be nice if you could skip the execution of the with statement's code block, if there was no match, which would simplify this to..

with rematch("(\d+)g", "123") as m:
print(m.group(1)) # only executed if the match occurred


..but this seems impossible based of what I can deduce from PEP 343

Any ideas? As I said, this is really trivial annoyance, almost to the point of being code-golf..

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