I was trying to make a custom complex class that looked something like this and it failed. I replaced complex with int and it also failed, but I tried float and it worked.

---fail
class A(complex):
    def __init__(self, test):
        super().__init__()

A(test=5)

---fail
class A(int):
    def __init__(self, test):
        super().__init__()

A(test=5)

---work
class A(float):
    def __init__(self, test):
        super().__init__()

A(test=5)