PEP8 changes

Adjusted to follow PEP8 guidelines (http://legacy.python.org/dev/peps/pep-0008/).

Formatted spacing -> 4 space indentation: http://legacy.python.org/dev/peps/pep-0008/#indentation
Condensed the lxml import into one line: http://legacy.python.org/dev/peps/pep-0008/#imports