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map-like function on dict values?

Carel Fellinger cfelling at iae.nl
Thu Feb 28 18:03:38 EST 2002 
Skip Montanaro <skip at pobox.com> wrote:
...
> Don't assume for loop iteration is your only culprit... ;-) List creation
> overhead can be as big a problem.  I added another test function called iter

yep, see my other posting:)

> which relies on 2.2's new "for k in dict" capability to completely avoid
> list creation.  (I also changed your range() to an xrange() to avoid the
> extra list allocation, and called clock() instead of time() to measure CPU
> time instead of elapsed time.  This is on a Linux system) Here's what I get
> on my laptop:

Ah a new contestent, double fun, better algoritme better timing (linux
too), but the real iter still wins, although by a very slight margin:)

>     iter 6.69
>     iteritems 28.36
>     mapvalue 8.12
...
  def iteriteritems(f, d):
          for k, v in d.iteritems():
                  d[k] = f(v)
...
>         timeit(iter, f, d)
          timeit(iteriteritems, f, d)
          timeit(iteritems, f, d)
>         timeit(mapvalue, f, d)

iter 10.95
iteriteritems 10.43
iteritems 52.15
mapvalue 12.88
-- 
groetjes, carel
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