TL;DR -> Install Pyenv its good for you. You'll thank me later.

So, a lot of people have issues with managing their different Python versions. There are plenty of "pythons" out there. There's cpython2, pypy, stackless, anaconda, cpython3 ...

The list could go on forever.

Thus it isn't a surprise to find people struggling with trying to leverage different versions of Python. I mean, things can get messy, when you have two versions of Python installed. I for example have five versions of Python installed.

Luckily, there's a tool out there that allows you to seamlessly change between the different versions of Python on your *nix operating system (sorry Windows folks, no dice). Its called Pyenv (you probably guessed that one).

On a mac, pyenv is pretty easy to install, using homebrew with:

brew install pyenv

For linux, you can use the following installer. Just to top it off here are the benefits:

• Manage multiple versions of the Python interpreter, this includes not only the language versions but also different interpreters entirely.
• Stay up to date with all the latest versions of Python that's coming out.
• Change seamlessly between the different versions of Python, you have complete control over what the python alias means.