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importlib.metadata: Use str.translate to improve performance of importlib.metadata.Prepared.normalized #143658
Description
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
Activity
[-]importlib.metadata: Use `translate` to improve performance of `canonicalize_name`[/-][+]importlib.metadata: Use `translate` to improve performance of `importlib.metadata.Prepared.normalized`[/+][-]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`[/+]gh-143658: importlib.metadata: Use `str.translate` to improve perform…
gh-143658: Use `str.lower` and `replace` to further improve performan…
pythongh-143658: importlib.metadata: Use `str.translate` to improve p…
pythongh-143658: Use `str.lower` and `replace` to further improve per…
jaraco commentedon Mar 20, 2026
Let it be stated that the referenced blog provides the rationale why this change is valuable.
jaraco commentedon Mar 20, 2026
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?
pythongh-143658: Use `str.lower` and `replace` to further improve per…