# test multiple inheritance of user classes class A: def __init__(self, x): print('A init', x) self.x = x def f(self): print(self.x) def f2(self): print(self.x) class B: def __init__(self, x): print('B init', x) self.x = x def f(self): print(self.x) def f3(self): print(self.x) class Sub(A, B): def __init__(self): A.__init__(self, 1) B.__init__(self, 2) print('Sub init') def g(self): print(self.x) print(issubclass(Sub, A)) print(issubclass(Sub, B)) o = Sub() print(o.x) o.f() o.f2() o.f3()