gh-138991: Update dataclass documentation for new eq behavior in Python 3.13 and add tests by Aniketsy · Pull Request #139007 · python/cpython

Aniketsy · 2025-09-16T22:28:43Z

#138991
This PR updates the documentation for the eq parameter in the dataclasses module to reflect the new field-by-field comparison behavior introduced in Python 3.13.
A .. versionchanged:: 3.13 notice has been added, and the previous tuple-based comparison for Python 3.12 and earlier is described for clarity.

Additionally, new tests have been added to verify the updated __eq__ implementation, including field-by-field comparison, type checking, and custom field equality logic.

Please let me know if my approach or fix needs any improvements . I’m open to feedback and happy to make changes based on suggestions.
Thankyou !

📚 Documentation preview 📚: https://cpython-previews--139007.org.readthedocs.build/

…d tests (python#138991)

…d tests

bedevere-app · 2025-09-17T10:52:56Z

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

…d tests

ericvsmith

Use more specific unittest methods.

…d tests

Aniketsy · 2025-09-28T04:44:17Z

@ericvsmith please review these changes when you get a chance.

Aniketsy · 2025-11-08T13:33:34Z

I have made the requested changes; please review again .

bedevere-app · 2025-11-08T13:33:40Z

Thanks for making the requested changes!

@ericvsmith: please review the changes made to this pull request.

github-actions · 2026-04-29T12:30:54Z

This PR is stale because it has been open for 30 days with no activity.

Aniketsy · 2026-06-11T15:55:07Z

@vstinner thanks for the review, i've updated please let me know if we need further improvements in this.

read-the-docs-community · 2026-06-11T15:58:14Z

Documentation build overview

📚 cpython-previews | 🛠️ Build #33097812 | 📁 Comparing 4991c6a against main (10595b1)

🔍 Preview build

1 file changed

± library/dataclasses.html

Use more specific unittest methods.

This reviews has been addressed. The tests now use assertEqual() and assertNotEqual() properly.

vstinner · 2026-06-11T16:24:39Z

Tests / Docs / Docs (pull_request): Failing after 15s

It failed on git fetch with fatal: shallow file has changed since we read it. Aha, that's just a random error.

vstinner

LGTM. The doc is rendered correctly, I checked.

vstinner · 2026-06-11T16:28:03Z

Oh, the "Docs / Docs" CI now fails with:

Run python Doc/tools/check-html-ids.py collect Doc/build/html -o Doc/build/html-ids-head.json.gz
python: can't open file '/home/runner/work/cpython/cpython/Doc/tools/check-html-ids.py': [Errno 2] No such file or directory

Let me click on [Update branch] to solve the issue.

Aniketsy · 2026-06-11T16:37:27Z

thanks for merging, and moving this forward.

miss-islington-app · 2026-06-11T17:15:34Z

Thanks @Aniketsy for the PR, and @vstinner for merging it 🌮🎉.. I'm working now to backport this PR to: 3.13, 3.14, 3.15.
🐍🍒⛏🤖

bedevere-app · 2026-06-11T17:15:50Z

GH-151372 is a backport of this pull request to the 3.15 branch.

bedevere-app · 2026-06-11T17:15:54Z

GH-151373 is a backport of this pull request to the 3.14 branch.

bedevere-app · 2026-06-11T17:15:59Z

GH-151374 is a backport of this pull request to the 3.13 branch.

vstinner · 2026-06-11T17:17:29Z

fatal: shallow file has changed since we read it

I created #151365 to track this issue.

vstinner · 2026-06-11T17:17:45Z

PR merged. Thanks @Aniketsy for updating the doc and writing some tests!

…in Python 3.13 (GH-139007) (#151374) gh-138991: Update dataclass documentation for new eq behavior in Python 3.13 (GH-139007) And add tests. (cherry picked from commit 402668b) Co-authored-by: Aniket <148300120+Aniketsy@users.noreply.github.com> Co-authored-by: Victor Stinner <vstinner@python.org>

…in Python 3.13 (GH-139007) (#151373) gh-138991: Update dataclass documentation for new eq behavior in Python 3.13 (GH-139007) And add tests. (cherry picked from commit 402668b) Co-authored-by: Aniket <148300120+Aniketsy@users.noreply.github.com> Co-authored-by: Victor Stinner <vstinner@python.org>

…in Python 3.13 (GH-139007) (#151372) gh-138991: Update dataclass documentation for new eq behavior in Python 3.13 (GH-139007) And add tests. (cherry picked from commit 402668b) Co-authored-by: Aniket <148300120+Aniketsy@users.noreply.github.com> Co-authored-by: Victor Stinner <vstinner@python.org>

Aniketsy added 4 commits September 16, 2025 10:41

Add a note to the platform.machine() documentation section

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Add a note to the platform.machine() documentation section

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Update dataclass documentation for new __eq__ behavior in 3.13 and ad…

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…d tests (python#138991)

Update dataclass documentation for new __eq__ behavior in 3.13 and ad…

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…d tests

Aniketsy requested a review from ericvsmith as a code owner September 16, 2025 22:28

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Update dataclass documentation for new behavior of __eq__ in 3.13. #138991

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Update dataclass documentation for new __eq__ behavior in 3.13 and ad…

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Update dataclass documentation for new __eq__ behavior in 3.13 and ad…

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Update dataclass documentation for new __eq__ behavior in 3.13 and ad…

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add note

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Aniketsy force-pushed the dataclass-eq-doc-update-3-13 branch from 03445c6 to 61af25c Compare November 8, 2025 13:32

Merge branch 'main' into dataclass-eq-doc-update-3-13

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bedevere-app Bot requested a review from ericvsmith November 8, 2025 13:33

github-actions Bot added the stale Stale PR or inactive for long period of time. label Apr 29, 2026

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move versionchanged block after 'ignored' sentence

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vstinner approved these changes Jun 11, 2026

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Merge branch 'main' into dataclass-eq-doc-update-3-13

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vstinner enabled auto-merge (squash) June 11, 2026 16:29

vstinner added needs backport to 3.13 bugs and security fixes needs backport to 3.14 bugs and security fixes needs backport to 3.15 pre-release feature fixes, bugs and security fixes labels Jun 11, 2026

vstinner merged commit 402668b into python:main Jun 11, 2026
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