polars, pydantic and deltalake come to mind

- https://pypi.org/project/polars/

- https://pypi.org/project/pydantic/

- https://pypi.org/project/deltalake/

Does Pydantic use rust? When I check the github repo, it shows 100% python.

The Rust re-write is being worked on in a separate repo: https://github.com/pydantic/pydantic-core

He's working on a rust rewrite, to be used in Pydantic 2.0

> The standard lib crypto module uses rust, too.

This couldn't matter less, but I think you're confused with the third-party Cryptography package, which uses Rust.

My bad, thanks for the correction!

I'm a huge fan of maturin but that might be a bit meta. It's a python build tool for wrapping rust projects. There github page has a list of projects using it and you might find more of what you are looking for: https://github.com/PyO3/maturin#examples