There are a number of improvements, including how you define them and the things you can do with them. Some of these tie in with other language features, e.g typing.NamedTuple[1].

There is also PEP 487[2], which means you can do more without needing a metaclass.

1. https://docs.python.org/3/library/typing.html#typing.NamedTu...

2. https://www.python.org/dev/peps/pep-0487/