On the __slots__, the article claims that these do: https://realpython.com/python-data-classes/#optimizing-data-classes https://realpython.com/python-data-class

On the __slots__, the article claims that these do: https://realpython.com/python-data-classes/#optimizing-data-classes https://realpython.com/python-data-classes/#optimizing-data-... EDIT: From PEP 557: https://www.python.org/dev/peps/pep-0557/#support-for-automatically-setting-slots https://www.python.org/dev/peps/pep-0557/#support-for-automa... “Support for automatically setting __slots__? At least for the initial release, __slots__ will not be supported. __slots__ needs to be added at class creation time. The Data Class decorator is called after the class is created, so in order to add __slots__ the decorator would have to create a new class, set __slots__, and return it. Because this behavior is somewhat surprising, the initial version of Data Classes will not support automatically setting __slots__. There are a number of workarounds: - Manually add __slots__ in the class definition. - Write a function (which could be used as a decorator) that inspects the class using fields() and creates a new class with __slots__ set.”