[Python-ideas] data structures should have an .any() method

[Paul Moore]

2009/9/5 Steven D'Aprano <steve at pearwood.info>:
> On Fri, 4 Sep 2009 10:01:28 pm Matteo Dell'Amico wrote:
>
>> Why? next(iter(obj)) means, pretty explicitly to me, "iterate on obj
>> and give me one element".
>
> To me, it says "give me the first element", not "give me any (an
> arbitrary) element" or "give me a random element".

The original use as described was for picking an "arbitrary" element,
because all of the elements were effectively the same - "any of the
elements in a data structure because you know that they all contain
the same information". For a random element, use random.choice, for
the first, use next(iter()). Either option satisfies the original
requirement - but the first is bound to be faster, so it seems
appropriate.

> Does anyone have a use-case for retrieving a single arbitrary element of
> an arbitrary sequence, without caring about any other elements? Is this
> really such a common operation that we need to consider it part of the
> interface for all collections? I doubt it.

Agreed.

Paul.