This should work (but doesn't):

Python 2.7.8+ (2.7:63dc1e32b715, Sep 30 2014, 19:24:46) 
[GCC 4.2.1 Compatible Clang 3.5.0 (207381)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import re
>>> re.match('(foo)', 'foo').group(1L)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IndexError: no such group
>>> 

I *think* the attached patch fixes it (but I'm not quite sure).

Here's the relevant mailing list thread: https://mail.python.org/pipermail/python-ideas/2014-September/029590.html.