gh-86519: Add prefixmatch APIs to the re module #31137
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These alleviate common confusion around what "match" means as Python is different than other popular languages in our use of the term as an API name. The original "match" names are NOT being deprecated. Source tooling like linters are expected to suggest using prefixmatch instead of match to improve code health and reduce cognitive burden of understanding the intent when reading code. See the documentation changes within this PR for a better description.
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`match = prefixmatch`
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## Summary The example for [FURB167](https://docs.astral.sh/ruff/rules/regex-flag-alias/#regex-flag-alias-furb167) has `re.match` with an `^` anchor to match the start of the string: ```python if re.match("^hello", "hello world", re.I): ``` But `re.match` already implicitly matches the start of the string: https://docs.python.org/3/library/re.html#search-vs-match Let's change the example to `re.search` so the anchor isn't redundant. (The anchor's actually irrelevant to the example for this rule about long or short flag names.) (Aside: There's a discussion about adding `re.prefixmatch` and [soft] deprecating `re.match` because of the confusion around it: https://discuss.python.org/t/add-re-prefixmatch-deprecate-re-match/105927, python/cpython#86519, python/cpython#31137.) ## Test Plan <!-- How was it tested? --> 1. Create feature branch 2. Push to my fork to run CI 3. Realise feature branches are disabled for forks in Ruff CI 4. Merge feature branch to my `main` 5. Push that 6. Be happy I did, because it failed because I missed something 7. Fixup, pushup 8. Passes [🎉](https://github.com/hugovk/ruff/actions/runs/21524112749)
Resolved conflicts: - Doc/whatsnew/3.14.rst: Used main's version (3.14 is released) - Lib/re/__init__.py: Removed __version__ (removed in main), updated docstring to reference 3.15 instead of 3.14 Added prefixmatch What's New entry to Doc/whatsnew/3.15.rst since the feature is now targeting Python 3.15.
- Change "25 years" to "30 years" to reflect actual time - Replace speculative "this decade, if ever" / "7 years" language with clear statement that we will never remove the original match name Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Fix traceback to include ^ anchor matching the pair pattern definition - Add \A anchor to one example as a teaching hint for readers - Update card game examples to demonstrate search/match/prefixmatch mix - Add explanatory paragraph about match and prefixmatch being identical - Rename compiled regex variables to use _re suffix (valid_hand_re, pair_re) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Using first_name/last_name patterns promotes the myth that names have simple, universal structures. Replace with: - "killer rabbit" with adjective/animal groups - "Norwegian Blue, pining for the fjords" for unlabeled groups
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Adds
prefixmatchAPIs to the re module as an alternate name for our long existingmatchAPIs to help alleviate a common Python confusion for those coming from other languages regular expression libraries.These alleviate common confusion around what "match" means as Python is different than other popular languages regex libraries in our use of the term as an API name. The original
matchnames are NOT being deprecated. Source tooling like linters, IDEs, and LLMs could suggest usingprefixmatchinstead of match to improve code health and reduce cognitive burden of understanding the intent of code when configured for a modern minimum Python version.See the documentation changes within this PR for a better description.
Documentation Preview: https://cpython-previews--31137.org.readthedocs.build/en/31137/