gh-138912: Improve MATCH_CLASS opcode performance #138915
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cdce8p
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Sep 15, 2025
Python/ceval.c
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| if (seen == NULL) { | ||
| return NULL; | ||
| PyObject *seen = NULL; | ||
| if (nattrs > 1) { |
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| if (nattrs > 1) { | |
| if (nargs > 1 || (nargs == 1 && nkwargs > 0)) { |
As mentioned in #138912, I'd also like to change this. If there are only keyword arguments, it's easy to see if two are the same name. Furthermore linters are able to detect these based on the AST alone.
It would also be great to say if we could suggest users to prefer keyword arguments. Not only are they more explicit, they are also faster. (No lookup of __match_args__ and, with the change, no expensive duplicate name detection.)
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Added this in f585253 with if (nargs > 0 && nattrs > 1). I can revert it if necessary.
Misc/NEWS.d/next/Core_and_Builtins/2025-09-15-13-28-48.gh-issue-138912.61EYbn.rst
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eendebakpt
approved these changes
Oct 28, 2025
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The CI failure seems unrelated. Updating the branch to rerun the CI just to be sure. |
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