Something

>>> s = 'foobar'
>>> m = re.compile('foo(baz)').search(s)
>>> if m.group(1) != None:
...   print m.group(1)
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'group'
>>>