There's a very minor Pep8 style violation on the last line here.  According to Pep8, Python scripts should end with a newline character (a blank line).

This doesn't actually affect the way the code runs.  Pep8 is just a style guide - a set of commonly accepted standards for writing easily readable and stylistically consistent Python scripts.  You can read Pep8 in its entirety on the Python website, if you want.  Fortunately, we don't have to: the reason that we set up SublimeLinter with flake8 is so that Sublime can keep track of these style violations for us.