strip not working on strings?

[dan.j.weber at gmail.com]

I'm using Python 2.3.5 and when I type the following in the interactive
prompt I see that strip() is not working as advertised:

>>>s = 'p p:p'
>>>s.strip(' :')
'p p:p'

Is this just me or does it not work? I want to get rid of all ' ' and
':' in the string. I've checked the doc and from what I can tell this
is what strip() is supposed to do. Thanks for any help.