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

polars-u64-idx
0.20.11

This version was deleted from PyPI around 2024-02-29. Installing fails with:
$ pip3 install polars-u64-idx==0.20.11 ERROR: Could not find a version that satisfies the requirement polars-u64-idx==0.20.11
View other deleted versions of polars-u64-idx

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/2024-02-28/ \ polars-u64-idx==0.20.11
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:
polars_u64_idx-0.20.11-cp38-abi3-macosx_10_12_x86_64.whl (23.7MB)
polars_u64_idx-0.20.11-cp38-abi3-macosx_11_0_arm64.whl (23.4MB)
polars_u64_idx-0.20.11-cp38-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (24.5MB)
polars_u64_idx-0.20.11-cp38-abi3-manylinux_2_24_aarch64.whl (25.0MB)
polars_u64_idx-0.20.11-cp38-abi3-win_amd64.whl (24.3MB)
polars_u64_idx-0.20.11.tar.gz (3.1MB)