NEWBIE: ishexdigit revisited

[Paul Rubin]

Kirk Strauser <kirk at strauser.com> writes:
> For production use, I'd factor out the 're' stuff (for performance) and add
> descriptive variable names (it doesn't cost anything) like so:
> 
>     import re
>     hexpattern = re.compile(r'[0123456789abcdefABCDEF]*$')
> ...
> That way, the pattern is only compiled once.

It normally only gets compiled once anyway, then cached.  If you
have a really large number of different regexps I guess the cache
can overflow and recompilation happens.