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

constrain
0.3.0

This version was deleted from PyPI around 2024-02-07. Installing fails with:
$ pip3 install constrain==0.3.0 ERROR: Could not find a version that satisfies the requirement constrain==0.3.0
View other deleted versions of constrain

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/2024-02-06/ \ constrain==0.3.0
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)

Or, download files manually

And install manually via pip:
ConStrain-0.3.0-py2.py3-none-any.whl (64.2KB)
ConStrain-0.3.0.tar.gz (74.3KB)