1class A:
2    def __init__(self, x):
3        print('A init', x)
4        self.x = x
5
6    def f(self):
7        print(self.x, self.y)
8
9class B(A):
10    def __init__(self, x, y):
11        A.__init__(self, x)
12        print('B init', x, y)
13        self.y = y
14
15    def g(self):
16        print(self.x, self.y)
17
18A(1)
19b = B(1, 2)
20b.f()
21b.g()
22