This post was published more than a few years ago (on 2017-06-10) and may contain inaccurate technical information, outmoded thoughts, or cringe takes. Proceed at your own risk.
Note to self: After installing Python 3.6 on your Mac, run /Applications/Python 3.6/Install Certificates.command so your SLL connections don’t fail.
The error you might get, when this is the case, is:
[crayon-64cc43bdc79c8057828516/]Python 3.6 no longer links to the macOS-supplied SSL libraries and now includes its own copy of OpenSSL, but it doesn’t automatically install the root certificates needed to validate connections. It seems the Python 3.6 installer warns you about this during the install, but it’s easy to miss. It’s also in the README, and there’s a behavior bug for Python suggesting that it get installed automatically. Thanks to this Stack Overflow post for the help.