king a function after defining it is that it makes explicit the author's intent for the function to be called immediately. Whereas if one simply calls the function immediately, it's less obvious if that was intentional or incidental. It also avoids repeating the name - the two actions, defining the function and calling it immediately are modeled separately, but linked by the decorator construct. The benefit of having a function construct (opposed to just invoking some behavior inline) is to serve as a scope in which the behavior occurs. It avoids polluting the global namespace with local variables, provides an anchor on which to attach documentation (docstring), keeps the behavior logically separated (instead of conceptually separated or not separated at all), and provides potential to re-use the behavior for testing or other purposes. This function is named as a pithy way to communicate, "call this function primarily for its side effect", or "while defining this function, also take it aside and call it". It exists because there's no Python construct for "define and call" (nor should there be, as decorators serve this need just fine). The behavior happens immediately and synchronously. >>> @invoke ... def func(): print("called") called >>> func() called Use functools.partial to pass parameters to the initial call >>> @functools.partial(invoke, name='bingo') ... def func(name): print('called with', name) called with bingo r