Data classes are "self-documenting" with respect to the "keys" you can expect to be present. Relatedly, they enable meaningful type hints: def some_method(in

Data classes are "self-documenting" with respect to the "keys" you can expect to be present. Relatedly, they enable meaningful type hints: def some_method(input: Dict[str, int]): ... You can just as easily call `some_method({"foo": 1})` as `some_method({"bar": 2})`. vs. def some_method(input: MyDataClassWithFoo): ... Now you can't pass a dict where the key is "bar" and presumably get a KeyError when it tries to look up a "foo" key, you can only pass a MyDataClassWithFoo.