Boilerplate

`if __name__ == '__main__': main()`_

Prevents main() from being executed during imports.

`#!/usr/bin/env/python`_

UNIX specific.

`#!/usr/local/bin/python`_

UNIX specific.

`#!/usr/bin/python`_

UNIX specific.

`# -*- coding: utf-8 -*-`_

Declares usage of UTF-8 characters in the script.