This is a basic text based CLI that can be run in any Python 3 IDE or interpreter with minimal extra libraries.
Keep in mind that even though the name is PythonOS, this is not a real OS that you can flash. It is simply a script that when run, acts as a basic command line.
However, you can change the initial setup function on your computer to run this file in a Python 3 IDE or interpreter upon boot.
/!\ WARNING /!\ I would not recommend doing this on your personal computer, as this may result in data loss or preventing you from accessing your PC normally.
I would suggest that if you choose to do this it is on a single board computer like a Raspberry Pi, since the OS that the Pi is running (Pi OS, formerly known as Raspbian) can be re-flashed to a microSD card.