gh-138991: Update dataclass documentation for new eq behavior in Python 3.13 and add tests #139007
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Doc/library/dataclasses.rst
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| .. versionchanged:: 3.13 | ||
| The generated ``__eq__`` method now compares each field individually (e.g., ``self.a == other.a and self.b == other.b``), rather than comparing tuples of fields as in previous versions. |
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Please wrap lines to 79 characters.
Also, please don't use Latin abbreviations, see the devguide for more information.
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Thanks! I’ve made the updates based on your suggestions.
Doc/library/dataclasses.rst
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| comparing tuples of fields as in previous versions. | ||
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| This method compares the class by comparing each field in order. Both | ||
| instances in the comparison must be of the identical type. |
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I think this sentence should come before the versionchanged note. It's a description of how the method works, which is more important than how it changed over time.
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| In Python 3.12 and earlier, the comparison was performed by creating | ||
| tuples of the fields and comparing them (for example, | ||
| ``(self.a, self.b) == (other.a, other.b)``). |
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I don't know how the formatting would work out, but I think the note about 3.12 should be part of the versionchanged note. Also, might it be worth mentioning why this matters? It would matter for any value V where V!=V. Of the built in types/values, I think this only matters for NaN (but I'm willing to be corrected). On the other hand, maybe this would be getting into too much detail for the documentation.
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For formatting, @StanFromIreland suggested wrapping lines to 79 characters.
I’ll update these changes for now:
-Moving the sentence before the versionchanged note.
For the other changes you suggested, I’d like to wait until they are confirmed before updating.
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By "formatting", I meant possibly multiple paragraphs in a versionadded block. I don't know if that's possible (or desirable).
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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 |
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@ericvsmith please review these changes when you get a chance. |
#138991
This PR updates the documentation for the
eqparameter in thedataclassesmodule to reflect the new field-by-field comparison behavior introduced in Python 3.13.A .. versionchanged:: 3.13notice 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/