Brett Cannon:

… over 3 years ago I set out to re-implement the Python Launcher for Unix in Rust. On July 24, 2021, I launched 1.0.0 of the Python Launcher for Unix… This gives you a py command on Unix which will always use the newest version of Python.

He goes on to describe some workflow niceties that a built in and also what this project is not about:

The Launcher is purely a convenience and not meant to be The Launcher For All Things; this should never end up in a Docker container.