Description

JelleZijlstra

opened on Apr 21, 2026

Issue body actions

Feature or enhancement

Proposal:

PEP-661 has not been accepted (python/steering-council#258), but I hope to still get it in for 3.15, and in view of the short time window available I'd like to already submit a PR so those interested can review the implementation already while the SC deliberates.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-148829: Implement PEP 661 #148831
• gh-148829: bump number of static types #149121
• gh-148829: Move sentinelobject.h to Include/cpython/ #149186
• gh-148829: Make sentinels' repr and module customizable #149654
• gh-148829: Add PySentinel_CheckExact() #149725
• [3.15] gh-148829: Add PySentinel_CheckExact() (GH-149725) #149766
• [3.15] gh-148829: Make sentinels' repr and module customizable (GH-149654) #150092

Reacted by M. Kocher and Harmon

Activity

1. JelleZijlstra

   added

   type-featureA feature request or enhancementA feature request or enhancement

   on Apr 21, 2026
2. JelleZijlstra

   self-assigned this

   on Apr 21, 2026
3. hugovk commented on Apr 21, 2026

   

   hugovk

   on Apr 21, 2026

   Member

   More actions

   And I'll be happy if any buildbot failures can be found before any last-minute merge on release day :)

   Reacted by Jelle Zijlstra
4. picnixz

   added

   interpreter-core(Objects, Python, Grammar, and Parser dirs)(Objects, Python, Grammar, and Parser dirs)

   3.15bugs and security fixesbugs and security fixes

   on Apr 21, 2026
5. JelleZijlstra

   added a commit that references this issue on Apr 28, 2026

   gh-148829: Implement PEP 661 (#148831)

   29a92ab
6. JelleZijlstra

   closed this as completedon Apr 28, 2026
7. JelleZijlstra

   added a commit that references this issue on Apr 29, 2026

   gh-148829: bump number of static types (#149121)

   d71e3bc
8. scoder commented on Apr 29, 2026

   

   scoder

   on Apr 29, 2026

   Contributor

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   Was it considered to add a macro alias PySentinel_CheckExact(o) for PySentinel_Check(o) ?
   Or is there an inherent reason why the sentinel type will never, ever allow inheritance?
9. hugovk commented on Apr 29, 2026

   

   hugovk

   on Apr 29, 2026

   Member

   More actions

   There's discussion about subclassing at https://discuss.python.org/t/pep-661-sentinel-values/9126/341: not now, maybe later.
10. vstinner

    added a commit that references this issue on Apr 30, 2026

    gh-148829: Move sentinelobject.h to Include/cpython/ (#149186)

    f0e90d7
11. vstinner

    added 2 commits that reference this issue on May 13, 2026

    gh-148829: Add PySentinel_CheckExact() (#149725)

    94df625

    [3.15] gh-148829: Add PySentinel_CheckExact() (GH-149725) (#149766)

    a5f77a1
12. JelleZijlstra

    added 2 commits that reference this issue on May 19, 2026

    gh-148829: Make sentinels' repr and module customizable (#149654)

    0821803

    [3.15] gh-148829: Make sentinels' repr and module customizable (GH-14…

    f523146

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