Does not work with Python 3

[einhverfr]

Python 2 is end of life and will be phased out on new systems over the upcoming while. It would be good to ensure this is safe with Python3.

I would recommend prefixing the modules with:
from __future__ import print_function

And then ensuring that calls to print use the Python3 syntax. This would then allow the code to run on 3 and 2 at the same time. My quick reading did not see any other concerning areas regarding division or unicode literals.