>>> from unittest.mock import create_autospec
>>> def f(): pass
... 
>>> m = create_autospec(f)
>>> m.side_effect = [1, 2]
>>> m()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 3, in f
  File "/compile/py3k-cpython/Lib/unittest/mock.py", line 872, in __call__
    return _mock_self._mock_call(*args, **kwargs)
  File "/compile/py3k-cpython/Lib/unittest/mock.py", line 931, in _mock_call
    result = next(effect)
TypeError: 'list' object is not an iterator