Real scenario I'm in right now:
- Need to build libraries to support 2.7, 3.6, plus future proofing for >=3.7
- CI workers have images which only python 2.7 and 3.6, platform team too busy to update them
- Mac Homebrew only supports >=3.7
There's no common environment between anything unless we use pyenv
I understand that virtualenv and maybe even pyenv are useful if you need different requirements for different projects using the same version of Python, as apparently pip installs packages globally. But for your setup, I don't get why something like pyenv really helps...
Yep, most people can just do this. Then, they want a little script over the top that downloads the different versions of Python for them -- just to make life easier for them. Wouldn't it be handy to also script the installation? It'd also probably be useful to automatically setup the version of Python I want to use when I switch folders, so I'm not constantly running the wrong version when I change projects.
... et voila, we've reinvented pyenv :).