python - 为什么python引用中的绑定实例方法不相等？

Question

>>> class foo(object):
...     def test(s):
...         pass
...
>>> a=foo()
>>> a.test is a.test
False
>>> print a.test
<bound method foo.test of <__main__.foo object at 0x1962b90>>
>>> print a.test
<bound method foo.test of <__main__.foo object at 0x1962b90>>
>>> hash(a.test)
28808
>>> hash(a.test)
28808
>>> id(a.test)
27940656
>>> id(a.test)
27940656
>>> b = a.test
>>> b is b
True

Answer 1

They're bound at runtime; accessing the attribute on the object rebinds the method anew each time. The reason they're different when you put both on the same line is that the first method hasn't been released by the time the second is bound.