list.clear() missing?!?

Felipe Almeida Lessa felipe.lessa at gmail.com
Tue Apr 11 12:53:51 EDT 2006


Em Ter, 2006-04-11 às 10:42 -0600, Steven Bethard escreveu:
> one of::
> 
>      del lst[:]
> 
>      lst[:] = []
> 
> or if you don't need to modify the list in place,
> 
>      lst = []
> 
> Personally, I tend to go Fredrik's route and use the first.

I love benchmarks, so as I was testing the options, I saw something very
strange:

$ python2.4 -mtimeit 'x = range(100000); '
100 loops, best of 3: 6.7 msec per loop
$ python2.4 -mtimeit 'x = range(100000); del x[:]'
100 loops, best of 3: 6.35 msec per loop
$ python2.4 -mtimeit 'x = range(100000); x[:] = []'
100 loops, best of 3: 6.36 msec per loop
$ python2.4 -mtimeit 'x = range(100000); del x'
100 loops, best of 3: 6.46 msec per loop

Why the first benchmark is the slowest? I don't get it... could someone
test this, too?

Cheers,

-- 
Felipe.




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