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

constava
1.0.0b3

This version was deleted from PyPI around 2023-10-06. Installing fails with:
$ pip3 install constava==1.0.0b3 ERROR: Could not find a version that satisfies the requirement constava==1.0.0b3
View other deleted versions of constava

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/2023-10-05/ \ constava==1.0.0b3
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:
constava-1.0.0b3-py3-none-any.whl (15.7MB)
constava-1.0.0b3.tar.gz (5.7MB)