Looks pretty good. But if you're going to open source it, you might as well make it a proper Python project and conform to style guides (Google's own for one).

Looks pretty good. But if you're going to open source it, you might as well make it a proper Python project and conform to style guides (Google's own for one). This one has all the tests in the same directory as other files instead of a 'tests' directory, it's missing requirements.txt and method names start with upper case.