fastest method to choose a random element

bukzor workitharder at gmail.com
Sat Jan 5 16:45:16 EST 2008


On Jan 5, 9:12 am, "Martin v. Löwis" <mar... at v.loewis.de> wrote:
> > Any other ideas?
>
> How about this:
>
> def random_pick(list, property):
>     L = len(list)
>     pos = start = random.randrange(L)
>     while 1:
>         x = list[pos]
>         if property(x): return x
>         pos = (pos + 1) % L
>         if pos == start:
>            raise ValueError, "no such item"
>
> Regards,
> Martin

I thought about this, but in the sequence "00012" (and property =
bool) the 1 will be returned four times as often as the 2. Maybe
that's ok...



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