Type __call__ on builtins._NotImplementedType as None. #12984
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Currently, this is intentionally incorrectly typed in order to produce a better mypy error message. But pyright (and presumably other type checkers) end up just treating instances of _NotImplementedType as callable. With this change, the mypy error message gets a little worse, but other type checkers can understand that instances of _NotImplementedType aren't callable, which I think is an improvement.
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According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉 |
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Thanks, this was one of my weirder ideas. This changes mypy's message for raise NotImplemented() from NotImplemented? not callable to "None" not callable
With the PR as is, pyright says Object of type "None" cannot be called but if you replace it with Never, pyright gives a better error: Invalid exception class or object (mypy says "Never" not callable)
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How are you testing pyright? I tried |
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I was testing locally and my version of pyright was a little stale. With latest pyright, there is no error. |
Currently, this is intentionally incorrectly typed in order to produce a better mypy error message. But pyright (and presumably other type checkers) end up just treating instances of _NotImplementedType as callable.
I'm happy to drop this if it's particularly important that mypy generate a good error message here, but IMO it would be better to change this so that other type checkers can understand that instances of _NotImplementedType aren't callable, at the cost of making the error message a little worse.