[issue45605] Return False from __contains__ method if object not hashable for set and dict

Serhiy Storchaka added the comment: This is a duplicate of issue18510. It was also discussed on the Python-Dev mailing list (maybe more than once). If you have some new arguments or something in past 8 years made the old arguments no longer valid please open a new discussion on the mailing

[issue45605] Return False from __contains__ method if object not hashable for set and dict

Eric V. Smith added the comment: I don't have any code that would care, but if there's one thing I've learned in 15 years of python core development, it's that this will break someone's code. If you want more feedback, you should probably bring this up for discussion on the python-ideas

[issue45605] Return False from __contains__ method if object not hashable for set and dict

Андрей Казанцев added the comment: Can you please specify in what cases we need to get an exception instead of False? It just seems very strange to me to rely on this behaviour. -- ___ Python tracker

[issue45605] Return False from __contains__ method if object not hashable for set and dict

Eric V. Smith added the comment: That seems like a pretty big change that could break a lot of existing code. I suggest writing a wrapper around "in" if you want this behavior. -- nosy: +eric.smith ___ Python tracker

[issue45605] Return False from __contains__ method if object not hashable for set and dict

New submission from Андрей Казанцев : Now if do something like `[] in set()` python raise an exception, but if an object isn't hashable then we know for sure that it isn't in the set. Propose return False for these cases. P.S. I would like to make a patch -- components: Library (Lib)