Had occasion to run this again on a new machine, and I've been exclusively using the excellent https://asdf-vm.com/ for managing installed python versions. The script as-was couldn't find python because it's not in the default location. And then when I'd fixed that there was an error because it defaulted to running with python 3, so pinned to python 2 with a .tool-versions file that asdf-vm reads before firing up a python version.
See commits for details.
Had occasion to run this again on a new machine, and I've been exclusively using the excellent https://asdf-vm.com/ for managing installed python versions. The script as-was couldn't find python because it's not in the default location. And then when I'd fixed that there was an error because it defaulted to running with python 3, so pinned to python 2 with a .tool-versions file that asdf-vm reads before firing up a python version.