Annotation and registration are indeed common and proper uses of decorators. What I dislike are mostly the inputs 8, 9, 13, 14, and 23 that could give nasty id

Annotation and registration are indeed common and proper uses of decorators. What I dislike are mostly the inputs 8, 9, 13, 14, and 23 that could give nasty ideas to an inexperienced developer, while a more experienced developer wouldn't need them to understand that a decorator is just a syntactic sugar and that, yes, "applying a decorator d to a function x [is] the same as writing the definition of x, then x = d(x)" (which the author seems to refute). I understand that those examples are solely intended to show that "it works", but they aren't educational to me.