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Title: Make type variable upper bound narrowing symmetric by ilevkivskyi · Pull Request #21350 · python/mypy · GitHub

Open Graph Title: Make type variable upper bound narrowing symmetric by ilevkivskyi · Pull Request #21350 · python/mypy

X Title: Make type variable upper bound narrowing symmetric by ilevkivskyi · Pull Request #21350 · python/mypy

Description: Optional static typing for Python. Contribute to python/mypy development by creating an account on GitHub.

Open Graph Description: Fixes #21199 Fixes #4952 This is kind of a simple-minded fix. The typeops around this are somewhat incomplete, but the opposite direction has been around for couple releases, and I don't think ...

X Description: Fixes #21199 Fixes #4952 This is kind of a simple-minded fix. The typeops around this are somewhat incomplete, but the opposite direction has been around for couple releases, and I don't th...

Opengraph URL: https://github.com/python/mypy/pull/21350

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fix: do not narrow expression type to TypeVar on equality comparison #21209 https://github.com/python/mypy/pull/21209
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[1.20 regression] Too aggressive type narrowing with type variables and equality https://github.com/python/mypy/issues/21199
isinstance can coerce a known type to become None https://github.com/python/mypy/issues/4952
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