Comment by lizard

Its notable, perhaps, that the

  if __name__ == "__main__":

block allows you to do this for a _module_, i.e. a single *.py file. If you want to do this for a package, add a `__main__.py`

You can also use either of these throughout your code so that you can have

  python -m foo
  python -m foo.bar
  python -m foo.bar.baz

each doing different, but hopefully somewhat related, things.