You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.
costrar was reported malicious
OSV:MAL-2024-1545 - Malicious code in costrar (PyPI)

costrar
8.0

This version was deleted from PyPI around 2024-06-07. Installing fails with:
$ pip3 install costrar==8.0 ERROR: Could not find a version that satisfies the requirement costrar==8.0
View other deleted versions of costrar

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/2024-06-06/ \ costrar==8.0
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:
Costrar-8.0.tar.gz (1.3KB)