I’m a little surprised at this point that Apple still doesn’t include a default Python 3.x on macOS. It’s the single thing keeping me from moving (as there’s a big difference between “just run this” and “first download this, then run this”).
My theory is that this is not going to be a nice change when they drop 2.7. Maybe one version will be released with both installed by default, then they'll use only 3.7/3.8 for the next decade. MacOS doesn't seem to care a lot about backwards compatibility recently.
I’m not so sure; /System/Library/Frameworks links for Python versions have been stable for a very long time (which surprised me at first but I imagine Apple has plenty of stuff of their own that uses Python). Even though they’ve since hacked a lot of the older versions with symbolic links to 2.7, versions back to 2.3 have valid paths.
Honestly the fact that they include a system Python 2 is a huge pain. You can't add packages to it, and you shouldn't add another Python 2 interpreter to the PATH. You end up having to use virtualenv which is a stupid hack.
I used PyInstaller for the first time this week to build a single binary executable for Linux. So far in limited use the result has been great. I think I'm gonna do OS X next.
