Mac’s come with a version of Python pre-installed; the issue there is that for a long time it was Python 2, and if you wanted to use Python 3, you had to self install it and make your own build.
Newer versions of MacOS come with Python 3 out of the box, and the build system that ships with Sublime Text 4 will automatically use it.
If you’re still using Sublime Text 3, then you still need to make your own build system for this because Python 3 is installed as an executable named
python3, but the build system that ships with ST3 just calls
Without creating a new build system or doing anything else, it’s not going to see Python 3 in a case like that. You could however make a symlink from
python or whatever else you like though.
In any case, all Sublime is doing is asking your OS to execute something named either
python3 (depending on your version of Sublime or the build you’ve created). So, you’re free to do something like install GarageBand and symlink it to the name
python if you want GarageBand to execute when you try to build Python programs (or if you will, Sublime neither knows nor cares).
That said, I would point out that creating your own build system is less “installing” and more “customizing”, in the same vein as changing settings.