Add support for PEP 661 (sentinels)#21454
Open
JelleZijlstra wants to merge 3 commits intopython:masterfrom
Open
Add support for PEP 661 (sentinels)#21454JelleZijlstra wants to merge 3 commits intopython:masterfrom
JelleZijlstra wants to merge 3 commits intopython:masterfrom
Conversation
Contributor
|
According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅ |
sobolevn
reviewed
May 10, 2026
| def func(x: int | MISSING | SPECIAL) -> None: | ||
| # We could reasonably do narrowing here, but currently we're pretty conservative | ||
| # about narrowing on ==. | ||
| if x == MISSING: |
Member
There was a problem hiding this comment.
Question: should we add a test case about narrowing types on isinstance(..., Sentinel)?
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
See PEP 661 and python/typing#2277