[Python-Dev] Comparing closures and arguments (was Re: Scoping vs augmented assignment vs sets (Re: 'fast locals' in Python 2.5) (original) (raw)

Phillip J. Eby pje at telecommunity.com
Wed Jun 14 22:01:33 CEST 2006

At 01:00 PM 6/14/2006 -0700, Josiah Carlson wrote:

> That claim isn't necessarily supported by your benchmark, which includes > the time to define the nested function 10 times, but calls it only 45 > times! Try comparing fcn1(1000) and fcn2(1000) - I suspect the results > will be somewhat closer, but probably still in favor of fcn1.

Please re-read the code and test as I have specified. You seem to have misunderstood something in there, as in the example I provide, helper is called 1,000,000 times (and is defined only once for each call of fcn2) during each fcn1 or fcn2 call, and helper is only defined once inside of fcn2.

Oops. I misread "[fcn2(x) for i in xrange(10)]" as "[fcn2(x) for x in xrange(10)]". The latter is so much more common of a pattern that I guess I didn't even look at what the loop variable was. Weird. I guess the mind is a terrible thing. :)

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