Update Python3 to 3.7 from the CLI without breaking APT

A crash course to using `update-alternatives`

First, check the current python3 version reference with python3:

You can have python37 output python 3.7.x (where x is the latest version digit) using update-alternatives. First, install Python 3.7.

To make the change, we’ll be using the tool update-alternatives. For more information about this tool…