[Python-Dev] Re: PEP 282 comments (original) (raw)

Jeremy Hylton jeremy@zope.com
Thu, 21 Mar 2002 19:13:48 -0500

"KB" == Kevin Butler <kbutler@campuspipeline.com> writes:

KB> [Jeremy]

Why do you need **kwargs at all?

KB> So we can postpone formatting the optional arguments into a KB> message until after we test if we're going to log the message or KB> not.

Aha! I must have gone out of my way to miss this. This is certainly a good thing. In the case of the ZEO server, we put all the trace and debug level logging calls inside "if debug:" We see a 20% speedup on compute intensive benchmarks when running with -O. So avoiding the string formatting is a nice savings.

On the other hand, extended calls -- where the caller passes *args or **args -- are a lot slower than regular calls. It would be interesting to benchmark both approaches. I expect that no-formatting is faster, but wouldn't bet too much on it. Apps probably still benefit from exploting if debug.

Jeremy