From: tismer at appliedbiometrics.com (Christian Tismer)
Date: Sun, 25 Apr 1999 20:05:15 GMT
Subject: Python too slow for real world
References: <372068E6.16A4A90@icrf.icnet.uk>
		<3720A21B.9C62DDB9@icrf.icnet.uk>
		<3720C4DB.7FCF2AE@appliedbiometrics.com>
		<3720C6EE.33CA6494@appliedbiometrics.com>
		<y0jaevznhha.fsf@vier.idi.ntnu.no>
		<glmvhemn4zx.fsf@caffeine.mitre.org> <y0j7lr0obcs.fsf@vier.idi.ntnu.no>
Message-ID: <3723757B.CF96D973@appliedbiometrics.com>
Content-Length: 1723
X-UID: 357                                                  


"Magnus L. Hetland" wrote:
> 
> Justin Sheehy <justin at linus.mitre.org> writes:
> 
> > mlh at idt.ntnu.no (Magnus L. Hetland) writes:
> >
> > > (And... How about builtin regexes in P2?)
> >
> > Um, why?  I don't see any need at all for them to move from
> > module-status to core-language-status.
> [...]
> >
> > In all seriousness, what reason do you have for making that
> > suggestion?  I am willing to believe that there might be a good reason
> > to do so, but it certainly isn't immediately obvious.
> 
> Now, that's really simple -- because re.py is slow. I thought maybe
> some of the slowness might be improved by a c-implementation, that's
> all. Not too important to me...

Now, true for re.py, but if you just care about speed,
you can abuse the underlying pcre module which is compiled.
For simple cases where I just needed to match something,
the "code" attribute of a compiled re object can be used
instead of the re object.
I admit this is a hack, but it gave me a speedup of factor 3
for a simple matching case. pcre's speed seems to be
in the same order of magnitude as regex was.

In the long term, I think it makes sense to build the rest of
re.py also into pcre. Then I still would not see any reason
to embed its functionaliy into the language.

ciao - chris

-- 
Christian Tismer             :^)   <mailto:tismer at appliedbiometrics.com>
Applied Biometrics GmbH      :     Have a break! Take a ride on Python's
Kaiserin-Augusta-Allee 101   :    *Starship* http://starship.python.net
10553 Berlin                 :     PGP key -> http://wwwkeys.pgp.net
PGP Fingerprint       E182 71C7 1A9D 66E9 9D15  D3CC D4D7 93E2 1FAE F6DF
     we're tired of banana software - shipped green, ripens at home