TypeError when calling super() in dataclass(slots=True) subclass
inheritance, python, python-dataclasses, slots
Solution
As seen here, the dataclass decorator creates a new class object, and so the `__closure__` attached to `hi()` is different to the one attached to the decorated class, and therefore the `super()` call cannot work without arguments due to relying on the `__closure__`.
Therefore, you need to change `super().hi()` to `super(Sub, self).hi()`.
Problem
I am trying to call a a superclass method from a dataclass with `slots=True` in Python 3.10.5. ``` from dataclasses import dataclass @dataclass(slots=True) class Base: def hi(self): print("Hi") @dataclass(slots=True) class Sub(Base): def hi(self): super().hi() Sub().hi() ``` I get the following error. ``` Traceback (most recent call last): File "...", line 16, in <module> Sub().hi() File "...", line 13, in hi super().hi() TypeError: super(type, obj): obj must be an instance or subtype of type ``` It works fine if I remove `slots=True` from `Sub`, or make it a non-dataclass with `__slots__` manually. The error remains if I instead do these to `Base`. `Sub.__mro__` is `(<class '__main__.Sub'>, <class '__main__.Base'>, <class 'object'>)` and `isinstance(Sub(), Base)` is `True`.