type(...) is treated the same as isinstance #5494

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1. github-actions

   added

   typechecking

   narrowingIssues with narrowing - root cause is usually narrowing, flow handling, or bothIssues with narrowing - root cause is usually narrowing, flow handling, or both

   on Nov 2, 2026
2. kinto0

   added the

   Bug

   issue type on Nov 2, 2026
3. Divyansh151005 commented on Nov 4, 2026

   

   Divyansh151005

   on Nov 4, 2026

   Contributor

   More actions

   #claim

   Plan: keep the isinstance-style narrowing for type(x) is C / type(x) == C, then, when C is a class literal, drop union members whose class is a proper subclass of C (a datetime can't have type(x) is date). bool literals are handled the same way (type(x) is int drops Literal[True]). NewType members and type[C] variables on the right-hand side are left alone, since those can still match at runtime.
4. github-actions

   assigned

   Divyansh151005

   on Nov 4, 2026
5. github-actions commented on Nov 4, 2026

   

   github-actionsBot

   on Nov 4, 2026 – with GitHub Actions

   More actions

   @Divyansh151005 you've claimed this issue — it's now assigned to you. Thanks for picking it up! 🎉
6. github-actions

   added

   has-open-pr

   on Nov 5, 2026
7. Divyansh151005

   added a commit that references this issue on Nov 11, 2026

   Narrow `type(x) is C` to exactly `C`, excluding subclasses

   ...

   This issue will close once commit 4bfc9d6 is merged into the 'main' branch.

   4bfc9d6
8. meta-codesync

   closed this as completedin 9590eedon Nov 11, 2026
9. crypt0lith

   added a commit that references this issue on Nov 11, 2026

   Narrow `type(x) is C` to exactly `C`, excluding subclasses (meta#5525)

   ...

   9590eed