1class A:
2    def __eq__(self, other):
3        print("A __eq__ called")
4        return True
5
6class B:
7    def __ne__(self, other):
8        print("B __ne__ called")
9        return True
10
11class C:
12    def __eq__(self, other):
13        print("C __eq__ called")
14        return False
15
16class D:
17    def __ne__(self, other):
18        print("D __ne__ called")
19        return False
20
21a = A()
22b = B()
23c = C()
24d = D()
25
26def test(s):
27    print(s)
28    print(eval(s))
29
30for x in 'abcd':
31    for y in 'abcd':
32        test('{} == {}'.format(x,y))
33        test('{} != {}'.format(x,y))
34