Problems while installing Python 3 on El Capitan
Once you have determined that it's not a homebrew problem using their troubleshooting guide my first suspicion would be that you are picking up the wrong version of the enum module. Make sure you are not setting PYTHONPATH anywhere (echo $PYTHONPATH at the command line will tell you) and try again.

The other possibility I would check is that you are running the right version of Python. which python should return /usr/bin/python (the version Apple installs), if not then you might want to check your PATH shell variable and temporarily set it to something else.