模拟side_effect迭代器可以在耗尽后重置吗？

Question

mock.reset_mock()不会重置副作用迭代器.有没有办法在不再创建模拟的情况下执行此操作？

>>> 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用模拟,但我怀疑,像生成器一样,它无法重新启动.

在指向正确的方向后,我看到(mock.py并且从不迟到),发现它side_effect是一个迭代器对象(一旦耗尽就无法重置):

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

并def reset_mock() 没有解决副作用.

Answer 1

正如user2357112所评论的那样，重新分配side_effect将解决您的问题。

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