Possibility to type `tuple.__hash__` to only accept hashable items

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Assessment

Difficulty
5/5
Estimated time
Over a week
Newbie friendliness
35/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Quiet
Tech stack
python

Research direction

Start with the typeshed definition of class tuple and its tuple.hash method, as described in the issue. Investigate whether restricting hashing to tuples of Hashable items is sound without breaking existing code, then document a decided typing approach and validate it against relevant type-checking behavior.

Written by the indexing model from the issue text.

Description

If a tuple contains unhashable entries, hashing it would raise TypeError. Is this possible to type? Currently, tuple.__hash__ is just a regular method that returns int.

This initial idea comes to mind, but on second thought, it would likely break a lot of code:

class tuple(Sequence[_T_co]):
    def __hash__(self: tuple[Hashable, ...]) -> int: ...
Dominant language
Python
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Merged PRs (30d)
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