Making decorators with optional arguments [duplicate]

Answer 1

Now that this old thread is back at the top anyway, lemme just throw in some Decorator-ception:

def magical_decorator(decorator):
    @wraps(decorator)
    def inner(*args, **kw):
        if len(args) == 1 and not kw and callable(args[0]):
            return decorator()(args[0])
        else:
            return decorator(*args, **kw)
    return inner

Now your magical decorator is just a single line away!

@magical_decorator
def foo_register(...):
    # bla bla

By the way, this works for any decorator. It just causes @foo to behave (as close as possibly) like @foo().