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

[Georg Brandl]

Antoine Pitrou schrieb:
> Nick Coghlan <ncoghlan at ...> writes:
>> 
>> Because it overspecifies the semantics of what you're trying to do. It
>> just happens that when the requirement is "get me any object in this
>> container" the design of Python means that the easiest implementation is
>> "get me the first object in this container".
> 
> I don't agree.
> Since iteration is such a frequent operation, any container which doesn't
> provide cheap iteration could be considered badly designed and/or badly
> implemented. Therefore it makes sense to rely on iteration when implementing
> other primitives.
> 
> People worrying that it expresses implementation rather than intent can write
> the trivial abstraction by themselves:
> 
> def any_item(x):
>     return next(iter(x))

or

any_item = compose(next, iter)

;)

Georg

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