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

imstr
0.0.16

This version was deleted from PyPI around 2023-12-18. Installing fails with:
$ pip3 install imstr==0.0.16 ERROR: Could not find a version that satisfies the requirement imstr==0.0.16
View other deleted versions of imstr

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/2023-12-17/ \ imstr==0.0.16
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:
imstr-0.0.16-py3-none-any.whl (5.0KB)
imstr-0.0.16.tar.gz (4.6KB)