I've been using a similar setup which I found online [0] when I was looking for a way to have multiple Python versions including working Jupyter notebooks etc.

It's been working great for me. Pyenv and virtualenvwrapper are really good. I'm not sure why this one needs pipsi, though. You can install CLI tools for both Python 2 and 3 using just Pyenv as demonstrated above.

[0] https://medium.com/@henriquebastos/the-definitive-guide-to-s...