模拟 side_effect 迭代器用完后可以重置吗？

mock.reset_mock()不会重置副作用迭代器。有没有办法在不再次创建模拟的情况下做到这一点？

>>> from mock import MagicMock
>>> mock = MagicMock(side_effect = [1,2])
>>> mock(), mock()
(1, 2)
>>> mock()

Traceback (most recent call last):
  File "<pyshell#114>", line 1, in <module>
    mock()
  File "C:\Python27\Lib\site-packages\mock.py", line 955, in __call__
    return _mock_self._mock_call(*args, **kwargs)
  File "C:\Python27\Lib\site-packages\mock.py", line 1013, in _mock_call
    result = next(effect)
StopIteration
>>> mock.reset_mock()
>>> mock()

Traceback (most recent call last):
  ...
StopIteration
>>> mock = MagicMock(side_effect = [1,2])
>>> mock(), mock()
(1, 2)
>>> 

目的是在后续测试中重新使用模拟，但我怀疑，就像生成器一样，它不能重新启动.

所以（迟到总比不到好）在被指向正确的方向后我看了看mock.py并发现side_effect是一个迭代器对象（不能是reset一旦耗尽）：

def __set_side_effect(self, value):
    value = _try_iter(value)
    ...

def _try_iter(obj):
    ...
    try:
        return iter(obj)
    except TypeError:
        # XXXX backwards compatibility
        # but this will blow up on first call - so maybe we should fail early?
        return obj

and def reset_mock()没有解决副作用。

正如 user2357112 评论的那样，重新分配side_effect会解决你的问题。

>>> from mock import MagicMock
>>>
>>> lst = [1, 2]
>>> mock = MagicMock(side_effect=lst)
>>> mock(), mock()
(1, 2)
>>> mock.side_effect = lst  # <-------
>>> mock(), mock()
(1, 2)