Use a different version of Python with virtualenv

Create virtual isolated Python environments.
More information: <https://virtualenv.pypa.io/>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

virtualenv --python={{path/to/pythonbin}} {{path/to/venv}}

click the source code to copy install virtualenv on any operating system with command-not-found.com