You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.

npfl139
2425.0.0a0

This version was deleted from PyPI around 2025-02-20. Installing fails with:
$ pip3 install npfl139==2425.0.0a0 ERROR: Could not find a version that satisfies the requirement npfl139==2425.0.0a0
View other deleted versions of npfl139

Install through StableBuild

You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
pip3 install \ -i https://YOUR_API_KEY.pypimirror.stablebuild.com/2025-02-19/ \ npfl139==2425.0.0a0
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Or, download files manually

And install manually via pip:
npfl139-2425.0.0a0-py3-none-any.whl (12.3KB)
npfl139-2425.0.0a0.tar.gz (6.7KB)