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

cppython-core
0.6.1.dev20

This version was deleted from PyPI around 2024-08-18. Installing fails with:
$ pip3 install cppython-core==0.6.1.dev20 ERROR: Could not find a version that satisfies the requirement cppython-core==0.6.1.dev20
View other deleted versions of cppython-core

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/2024-08-17/ \ cppython-core==0.6.1.dev20
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:
cppython_core-0.6.1.dev20-py3-none-any.whl (11.2KB)
cppython-core-0.6.1.dev20.tar.gz (11.0KB)