I'm just a viewer of that course. I guess for Mac users, it's easy, cause MacOS already comes with Python (3.x?) preinstalled. The course author himself video streams from the MacOS system.
https://developer.apple.com/documentation/macos_release_note...
> Scripting language runtimes such as Python, Ruby, and Perl are included in macOS for compatibility with legacy software. Future versions of macOS won’t include scripting language runtimes by default, and might require you to install additional packages. If your software depends on scripting languages, it’s recommended that you bundle the runtime within the app.
Also: The Mac comes with Python 2. I'm using Python 3, and hope that everyone will indeed install it!