https://github.com/python/cpython/commit/28fb13cb33d569720938258db68956b5f9c9eb40 commit: 28fb13cb33d569720938258db68956b5f9c9eb40 branch: main author: Hugo van Kemenade <[email protected]> committer: hugovk <[email protected]> date: 2026-02-06T19:38:58+02:00 summary:
gh-143658: Use `str.lower` and `replace` to further improve performance of `importlib.metadata.Prepared.normalized` (#144083) Co-authored-by: Henry Schreiner <[email protected]> files: A Misc/NEWS.d/next/Library/2026-01-20-20-54-46.gh-issue-143658.v8i1jE.rst M Lib/importlib/metadata/__init__.py diff --git a/Lib/importlib/metadata/__init__.py b/Lib/importlib/metadata/__init__.py index 9b723b4ec15e12..7cf4d29d330c91 100644 --- a/Lib/importlib/metadata/__init__.py +++ b/Lib/importlib/metadata/__init__.py @@ -890,14 +890,6 @@ def search(self, prepared: Prepared): return itertools.chain(infos, eggs) -# Translation table for Prepared.normalize: lowercase and -# replace "-" (hyphen) and "." (dot) with "_" (underscore). -_normalize_table = str.maketrans( - "ABCDEFGHIJKLMNOPQRSTUVWXYZ-.", - "abcdefghijklmnopqrstuvwxyz__", -) - - class Prepared: """ A prepared search query for metadata on a possibly-named package. @@ -933,9 +925,8 @@ def normalize(name): """ PEP 503 normalization plus dashes as underscores. """ - # Emulates ``re.sub(r"[-_.]+", "-", name).lower()`` from PEP 503 - # About 3x faster, safe since packages only support alphanumeric characters - value = name.translate(_normalize_table) + # Much faster than re.sub, and even faster than str.translate + value = name.lower().replace("-", "_").replace(".", "_") # Condense repeats (faster than regex) while "__" in value: value = value.replace("__", "_") diff --git a/Misc/NEWS.d/next/Library/2026-01-20-20-54-46.gh-issue-143658.v8i1jE.rst b/Misc/NEWS.d/next/Library/2026-01-20-20-54-46.gh-issue-143658.v8i1jE.rst new file mode 100644 index 00000000000000..8935b4c655023a --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-01-20-20-54-46.gh-issue-143658.v8i1jE.rst @@ -0,0 +1,4 @@ +:mod:`importlib.metadata`: Use :meth:`str.lower` and :meth:`str.replace` to +further improve performance of +:meth:`!importlib.metadata.Prepared.normalize`. Patch by Hugo van Kemenade +and Henry Schreiner. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
