Message257056
As Guido pointed out on -ideas, hashing already uses the convention of `__hash__ is None` to declare a type unhashable, and `collections.abc.Hashable.__subclasshook__` already checks for that.
Meanwhile, setting `__iter__` and `__reversed__` to `None` already raises a `TypeError` on `iter` and `reversed` (although not with the most helpful description).
So, maybe that should be documented as the standard way to unimplement `__iter__` and `__reversed__`, and `collections.abc.Iterable` should check that the looked-up `__iter__` is not `None` (and presumably typecheckers doing the equivalent for both `Iterable` and `Reversible`)? |
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2015-12-26 23:28:34 | abarnert | set | recipients:
+ abarnert |
2015-12-26 23:28:34 | abarnert | set | messageid: <1451172514.85.0.291744732201.issue25958@psf.upfronthosting.co.za> |
2015-12-26 23:28:34 | abarnert | link | issue25958 messages |
2015-12-26 23:28:34 | abarnert | create | |
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