PEP8 styling

[stefanv]

Python code should conform to the PEP8 standard:

https://www.python.org/dev/peps/pep-0008/

E.g., variable_names should be separated by underscores, so should module_name.py, but ClassNames are CamelCaps.

Always spaces, never TAB characters.

There should be spaces between operators, i.e. a + (b * c) not a+(b*c).

[stefanv]

A good checker for this is Flake8 (which can easily be hooked into most editors)--ask me if you need a hand!