[Python-Dev] 2.3 startup speed?
Guido van Rossum
guido@python.org
Fri, 11 Jul 2003 12:45:51 -0400
> I've got a plan, which I'll implement today unless someone can find a
> hole in it. The warnings module stores 5-tuples of filter information,
> including two compiled regular expressions. There are two filters
> installed by default, which is why we load re during startup.
>
> The two default filters use the regular expression "". So we're getting
> absolutely no benefit from those regular expressions. I propose to
> modify the two regex slots in the filter tuple to also store None, where
> None means matching anything.
>
> If we make that change, then we can install the default filters without
> importing re. A quick test of this change improved startup time by 20%.
It seems you already implemented this; I approve (though I hope some
other folks will carefully review the changes to warnings.py, which
are a bit more extensive than I feel comfortable with this close to a
release).
> Unfortunately, even with a 20% boost, it still takes twice as long to do
> python -c "pass".
There's a little time for more research into this.
--Guido van Rossum (home page: http://www.python.org/~guido/)