[pseudalopex]

Data classes are just regular classes with some methods generated for you. For now you still have to specify __slots__ manually to save memory.

[mrfusion]

So what’s the point of specifying the types?

[eesmith]

Over the last few years Python has gained a type annotation system. The primary goals are to improve testing, improve documentation (the type information is more likely to stay synchronized than docstring annotations), and improve user-feedback in environments like an IDE or Jupyter notebook.

These are called "type hints" because they are not enforced by the Python runtime.