Last time I used Python on macOS and Windows I manually installed the official version from python.org and used pip and virtualenv. It wasn't too bad but it seems things have changed in the last 6 years or so? Or is this still the most flexible way to go?
I would be grateful for any guidance.
Otherwise if you're trying to use some python project with particular dependencies pyenv is a good way to get a specific python version. But if the project has a lot of native dependencies (think scientific computing with lots of fortran, C++, etc. code to compile) then you're almost certainly better off with conda as a higher-level entire binary system manager.
For managing virtual environments on my preferred shell (Fish), I use (and maintain) VirtualFish [2].
For managing project dependencies, I activate environments via VirtualFish and then use Poetry [3] to update the dependencies within the environments.
[1]: https://github.com/danhper/asdf-python