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GeezerVison is showing github.com — gh-137065: Unmerge types.UnionType and typing.Union by serhiy-storchaka · Pull Request #137069 · python/cpython

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@serhiy-storchaka

@serhiy-storchaka serhiy-storchaka commented Jul 24, 2025 •
edited by github-actions Bot
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Partially revert GH-105499.

types.UnionType no longer an alias of typing.Union and no longer subscriptable, but subscribing typing.Union returns an instance of types.UnionType. typing.Union can no longer be used in the isinstance() checks.

  • Issue: Merge 'types.UnionType' with typing._UnionGenericAlias, not typing.Union #137065

📚 Documentation preview 📚: https://cpython-previews--137069.org.readthedocs.build/

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@serhiy-storchaka
serhiy-storchaka requested a review from JelleZijlstra July 24, 2025 08:27
@serhiy-storchaka serhiy-storchaka added the needs backport to 3.14 bugs and security fixes label Jul 24, 2025
@serhiy-storchaka
serhiy-storchaka requested review from AlexWaygood and rhettinger as code owners July 24, 2025 08:27
@bedevere-app bedevere-app Bot added the awaiting core review label Jul 24, 2025
@bedevere-app bedevere-app Bot mentioned this pull request Jul 24, 2025
Merge 'types.UnionType' with typing._UnionGenericAlias, not typing.Union #137065
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@StanFromIreland StanFromIreland mentioned this pull request Jul 24, 2025
Fix Union type merging to use types.UnionType instead of typing.Union #137068
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@serhiy-storchaka
pythongh-137065: Unmerge types.UnionType and typing.Union
fb8bc3e 
Partially revert pythonGH-105499.

types.UnionType no longer an alias of typing.Union and no longer subscriptable,
but subscribing typing.Union returns an instance of types.UnionType.
typing.Union can no longer be used in the isinstance() checks.
@serhiy-storchaka
serhiy-storchaka force-pushed the typing-union branch from e57751f to fb8bc3e Compare July 24, 2025 09:24
JelleZijlstra
JelleZijlstra requested changes Jul 25, 2025
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@JelleZijlstra JelleZijlstra left a comment

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I don't think anything should be changed here.

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@bedevere-app bedevere-app Bot added awaiting changes and removed awaiting core review labels Jul 25, 2025
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bedevere-app Bot commented Jul 25, 2025

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When you're done making the requested changes, leave the comment: I have made the requested changes; please review again.
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JelleZijlstra
JelleZijlstra reviewed Sep 15, 2025
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Comment thread Doc/whatsnew/3.14.rst
- Both syntaxes for creating a union now produce the same string representation in
``repr()``. For example, ``repr(Union[int, str])``
is now ``"int | str"`` instead of ``"typing.Union[int, str]"``.
- Unions created using the old syntax are no longer cached. Previously, running

@JelleZijlstra JelleZijlstra Sep 15, 2025

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Not sure why this was removed; the text would seem to still apply under this PR.

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@serhiy-storchaka serhiy-storchaka added the DO-NOT-MERGE label Sep 16, 2025
@serhiy-storchaka
serhiy-storchaka marked this pull request as draft September 16, 2025 09:07
@bedevere-app bedevere-app Bot removed the awaiting changes label Sep 16, 2025
@serhiy-storchaka

serhiy-storchaka commented Sep 16, 2025

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I now think that we need a full revert. See #138967.
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@github-actions

github-actions Bot commented Apr 27, 2026

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This PR is stale because it has been open for 30 days with no activity.
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@github-actions github-actions Bot added the stale Stale PR or inactive for long period of time. label Apr 27, 2026
@serhiy-storchaka serhiy-storchaka added the needs backport to 3.15 bugs and security fixes label May 30, 2026
@github-actions github-actions Bot removed the stale Stale PR or inactive for long period of time. label Jun 1, 2026
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github-actions Bot commented Sep 3, 2026

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This PR is stale because it has been open for 90 days with no activity.
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@github-actions github-actions Bot added the stale Stale PR or inactive for long period of time. label Sep 3, 2026
@ambv

ambv commented Oct 20, 2026

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This PR is superseded by #138967, a newer open pull request for the same issue (gh-137065), and it no longer merges cleanly. Closing to cull the number of open pull requests. Do not reopen this pull request without getting a go-ahead from a triager or core developer.
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@ambv ambv closed this Oct 20, 2026
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@JelleZijlstra JelleZijlstra JelleZijlstra requested changes
@AlexWaygood AlexWaygood Awaiting requested review from AlexWaygood AlexWaygood is a code owner
@rhettinger rhettinger Awaiting requested review from rhettinger rhettinger is a code owner
@AA-Turner AA-Turner Awaiting requested review from AA-Turner AA-Turner will be requested when the pull request is marked ready for review AA-Turner is a code owner

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3 participants

@serhiy-storchaka @ambv @JelleZijlstra
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