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

pyspex
1.4.0rc2

This version was deleted from PyPI around 2024-02-21. Installing fails with:
$ pip3 install pyspex==1.4.0rc2 ERROR: Could not find a version that satisfies the requirement pyspex==1.4.0rc2
View other deleted versions of pyspex

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/2024-02-19/ \ pyspex==1.4.0rc2
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:
pyspex-1.4.0rc2-py3-none-any.whl (91.6KB)
pyspex-1.4.0rc2.tar.gz (94.6KB)