Description

hugovk

opened on Jan 10, 2026

Issue body actions

Feature or enhancement

Proposal:

We can apply @henryiii's improvement to packaging in pypa/packaging#1030 (see also https://iscinumpy.dev/post/packaging-faster/) to improve the performance of canonicalize_name and make it ~3.7 times faster.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-143658: importlib.metadata: Use str.translate to improve performance of importlib.metadata.Prepared.normalized #143660
• gh-143658: Use str.lower and replace to further improve performance of importlib.metadata.Prepared.normalized #144083

Activity

1. hugovk

   added

   type-featureA feature request or enhancementA feature request or enhancement

   performancePerformance or resource usagePerformance or resource usage

   topic-importlib

   on Jan 10, 2026
2. picnixz

   added

   stdlibStandard Library Python modules in the Lib/ directoryStandard Library Python modules in the Lib/ directory

   on Jan 10, 2026
3. picnixz

   changed the title [-]importlib.metadata: Use `translate` to improve performance of `canonicalize_name`[/-] [+]importlib.metadata: Use `translate` to improve performance of `importlib.metadata.Prepared.normalized`[/+] on Jan 10, 2026
4. picnixz

   changed the title [-]importlib.metadata: Use `translate` to improve performance of `importlib.metadata.Prepared.normalized`[/-] [+]importlib.metadata: Use `str.translate` to improve performance of `importlib.metadata.Prepared.normalized`[/+] on Jan 10, 2026
5. hugovk

   added a commit that references this issue on Jan 13, 2026

   gh-143658: importlib.metadata: Use `str.translate` to improve perform…

   cbf9b8c
6. hugovk

   closed this as completedon Jan 13, 2026
7. hugovk

   added a commit that references this issue on Feb 6, 2026

   gh-143658: Use `str.lower` and `replace` to further improve performan…

   28fb13c
8. thunder-coding

   added 2 commits that reference this issue on Feb 15, 2026

   pythongh-143658: importlib.metadata: Use `str.translate` to improve p…

   ba90f74

   pythongh-143658: Use `str.lower` and `replace` to further improve per…

   9ecbd9f
9. jaraco commented on Mar 20, 2026

   

   jaraco

   on Mar 20, 2026

   Member

   More actions

   We can apply @henryiii's improvement to packaging in pypa/packaging#1030 (see also https://iscinumpy.dev/post/packaging-faster/) to improve the performance of canonicalize_name and make it ~3.7 times faster.

   Let it be stated that the referenced blog provides the rationale why this change is valuable.
10. jaraco commented on Mar 20, 2026

    

    jaraco

    on Mar 20, 2026

    Member

    More actions

    In python/importlib_metadata#533 (comment), I measured the performance benefit and find that it saves ~300 ns per call (on an M3 Mac pro). It's going to take a lot of calls to recoup the value from this change, and most users are never going to notice the benefit. Is there any known use case where we know users will benefit meaningfully from this change?
11. ljfp

    added a commit that references this issue on Apr 25, 2026

    pythongh-143658: Use `str.lower` and `replace` to further improve per…

    9e04a8f
12. jaraco

    added a commit that references this issue on Oct 31, 2026

    gh-160386: Apply changes from importlib_metadata 9.1 (#160387)

    5a97efe

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