regular expression questions using module re

[Gribouillis]

For question 1, the match object will always have 5 groups, for example

>>> import re
>>> p = re.compile(r'(f)(o)(o)|(b)(a)r')
>>> match = p.search('This is a foo thing')
>>> match.groups()
('f', 'o', 'o', None, None)
>>> match = p.search('This is a bar thing')
>>> match.groups()
(None, None, None, 'b', 'a')

For question 2, I don't understand the question. An example would help.