Best way to extract an item from a set of len 1

Fredrik Lundh fredrik at
Wed Jan 25 10:05:31 EST 2006

Tim Chase wrote:

> I suppose I was looking for something like
> >>> item = s.aslist()[0]
> which feels a little more pythonic (IMHO).  Is one solution
> preferred for speed over others (as this is happening in a fairly
> deeply nested loop)?

the obvious solution is

    item = list(s)[0]

but that seems to be nearly twice as slow as [x for x in s][0]
under 2.4.  hmm.

here's a faster variant:

    item = iter(s).next()

but at least on my machine, your two-step solution

    item = s.pop(); s.add(item)

seems to be even faster.


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