After many years of Django development I've settled on what I find the simplest solution. It includes activation of virtual environments when I cd into a directory.

pyenv for installing and managing python versions.

direnv for managing environments and environment variables (a highly underrated package imo).

With those two installed I just include a .envrc file in every project. It looks like this:

layout python ~/.pyenv/versions/3.11.0/bin/python3

export VARIABLE1=variable1

export VARIABLE2=variable2

etc...