SSL: CERTIFICATE_VERIFY_FAILED when trying to download on Mac (missing setup step)

[andrewtremblay]

If you're getting a SSL: CERTIFICATE_VERIFY_FAILED error when trying to download, it's because Python 3.x on OSX has no certificates at all, and can't validate any SSL connections.

The workaround for this is to install certifi

pip install certifi

and then call the install certificates command from your applications folder

/Applications/Python\ 3.6/Install\ Certificates.command

Original source of the solution: https://stackoverflow.com/a/42334357