[Python-ideas] Introduce collections.Reiterable

Tim Delaney timothy.c.delaney at gmail.com
Sat Sep 21 02:18:26 CEST 2013

On 21 September 2013 10:05, Tim Delaney <timothy.c.delaney at gmail.com> wrote:

>> Dismissing legal code as 'pathological', as more than one person has,
>> does not cut it as a design principle.
> To me, that is a reiterable. It might not give the same results each time
> through, but you can iterate, it stops, then you can iterate over it again
> - it won't raise an exception trying to do so. So not what I would consider
> a pathological case - though definitely an unusual case and one that
> obviously wouldn't work in many situations that require reiterables to
> return the same values in the same order each time through.
> So we've got two classes of reiterables here
> - anything that can be iterated through, and then iterated through again,
> for which obj is not iter(obj) will work in all but what I consider to be
> pathological cases;
> - iterables that can be iterated through multiple times, returning the
> same objects in the same order each time through, for which I don't think a
> test is possible.

Also, pathological is probably not the best term to use. Instead,
substitute "deliberately breaks a well-established protocol". It may make
sense to do so in certain circumstances, but you can't expect anyone else
to play nice with you if you don't play nice with them.

Tim Delaney
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