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 can fold additional attributes into a class definition. While it's technically possible to create a new class that wraps an original class definition, this doesn't seem to be very useful as a design pattern. It's also possible to create a new class that is a subclass of the original decorated class definition. This may be baffling to users of the decorator. It's also possible to delete features from a class definition, but this seems perfectly awful.
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