I read through the 3.3 regex howto and have made various edits in the attached patch. * describe how \w is different when used in bytes and Unicode patterns. * describe re.ASCII flag to change that behaviour. * remove a personal reference ('I generally prefer...') * some small edits and re-wording.
Slightly revised version that modifies the discussion of when to pre-compile a regex and when to not bother. I don't think this is a very important issue, so I don't think it needs a long discussion.
Well, this is already too long IMO. Two sentences should suffice. If you are calling a regex very often in a loop, then it makes sense to compile it. Otherwise, don't bother.