Simple PEP8 changes

I did some simple [PEP8](http://www.python.org/dev/peps/pep-0008/) changes to make your code more readable to most Python developers. Feel free to merge or reject this.

I didn't change everything as style is always also a question of taste (e.g. I left most of the vertical aligned operators), although I do recommend to fully stick to the PEP8 style, as it is being used for probably around 95% of all Python projects. That makes the Python coding style across all projects very consistent.

As a PEP8 checker and static code analysis tool (will detect things like unused or undefined variables) I'd recommend [flake8](https://pypi.python.org/pypi/flake8).