This little helper function returns True if called with a punctuation character and False with any other:
>>> from xlutils.margins import ispunc
>>> ispunc('u')
False
>>> ispunc(',')
True
It also works fine with unicode characters:
>>> ispunc(u',')
True
>>> ispunc(u'w')
False
It does not, however, return sensible answers if called with more than one character:
>>> ispunc(',,,')
False