Right, I think most developers know that it's a bad idea to mess with the old, unmaintained system versions of Python, Ruby, or Perl. Almost everyone I know uses Homebrew to install the bleeding edge versions separately, and that will save you a world of pain.

For Python folks, just install pyenv/pipenv and you can easily maintain `system` (Python), Python2.7x, Python3.7.3, &c as separate environments. For Ruby people it's rbenv.