python - __ne__ 是否使用重写的 __eq__？

Question

假设我有以下程序:

class A(object):                                                                                                                                                                                                                                                              
    def __eq__(self, other):
        return True

a0 = A() 
a1 = A() 
print a0 != a1

如果您使用 Python 运行它，输出为 True。我的问题是

1. __ne__ 方法未实现，Python 是否落在默认方法上？
2. 如果 Python 依赖于默认方法来确定两个对象是否相等，它不应该调用 __eq__ 然后取反结果吗？

Answer 1

来自 the docs :

There are no implied relationships among the comparison operators. The truth of x==y does not imply that x!=y is false. Accordingly, when defining __eq__(), one should also define __ne__() so that the operators will behave as expected.