Analogous to decorating a function, we can write a class decorator to add features to a class definition. The essential rules are the same. The decorator is a function (or callable object). It receives a class object as an argument and returns a class object as a result.

We have a limited number of join points inside a class definition as a whole. For the most part, a class decorator will fold additional attributes into a class definition. It's technically possible to create a new class that wraps an original class definition. This is challenging, since the wrapping class must be very generalized. It's also possible to create a new class that is a subclass of the decorated class definition. This may be baffling to users of the decorator. It's also possible to delete features from a class definition, which seems perfectly awful.

One sophisticated class decorator was shown previously. The functools.Total_Ordering decorator injects a number of new method functions into...