[ojii]

One tiny correction:

> decorators are functions that take a callable argument and return a new callable

there's nothing forcing a decorator to return a callable. A decorator _could_ return anything it wants. I don't know why you would want that, but Python won't stop you.

[backprojection]

They also don’t have to act on callables, see @dataclass for instance.

[ojii]

Classes are callable.

[Spivak]

You can abuse this fact with type hunting to get a ParamSpec of a class's __init__ arguments.

But yeah type systems get weird at the margins. Your class is an instance of type which has a __call__ method which creates an instance of your class.