Syntactic sugar to replace '__name__' idiom with decorator

hello_world.py

from main import execute

@execute
def main():
    do_something()

def do_something():
    print "Hello World"

main.py

"Convenience decorators for programs 'main'."
import atexit 
import collections

def execute(func):
    """Register decorated function as main routine of program.

    If the module is run as a script, the function will be registered to run
    at exit:

    >>> @execute
    ... def main():
    ...     print "Hello World"

    The decorator can be made to register the function regardless of which
    module is resides in:

    >>> @execute(True)
    ... def main():
    ...     print "Hello World"

    This decorator uses the atexit moodule so may not work correctly with code
    that uses sys.exitfunc.
    """
    if not isinstance(func, collections.Callable):
        if func:
            return atexit.register
        return program
    if func.__module__ == '__main__':
        atexit.register(func)
    return func