[Python-ideas] __iter__ implies __contains__?

[Masklinn]

On 2011-10-01, at 20:33 , Antoine Pitrou wrote:
> Ah, thanks for the pointer.
> I think we should add a custom IOBase.__contains__ raising a TypeError,
> then. The current semantics don't match what most people would expect
> from a "file containment" predicate.

I think it'd also be nice to add them to some "chopping block" list for
Python 4: I've yet to see these fallbacks result in anything but pain
and suffering, and they can be genuinely destructive and cause hard-to-
track bug, especially with modern Python code's tendency to use
(non-restartable) iterators and generators (send a generator to a
function which seems to take them, it performs some sort of
containment check before processing, the containment consumes the
generator and proceeds to not do any processing…)