Import checks and doctests you can run before any script code anyway, and exit() if needed. The advantage of `if __name__ == "__main__":`, is that you can impo

Import checks and doctests you can run before any script code anyway, and exit() if needed. The advantage of `if __name__ == "__main__":`, is that you can import the script as module on other code, as in that case __name__ will not be __main__.