Start your file with a module docstring. Do not put a shebang line (#!/usr/bin/python) or copyright notice, or anything else. Follow the docstring with your imports; don't put an author line.
Exception: if the python file is meant to be executable, it should start with the following shebang line:
!/usr/bin/env python
Rationale: a shebang line is useless for non-executable files. An author line just gets out of date, and is better determined by looking at source control history in any case. Code is automatically copyrighted; a copyright line doesn't help. No need to put this useless boilerplate at the top of the file!
According to Khan Academy's style guide: https://sites.google.com/a/khanacademy.org/forge/for-developers/styleguide/python