Create a mock function in python

>>> from mock import create_autospec
>>> def my_func(a, b, c):
...     print a, b, c
...
>>> my_mock_func = create_autospec(my_func, return_value="I am a mock")
>>> my_mock_func()
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "<string>", line 2, in my_func
TypeError: <lambda>() takes exactly 3 arguments (0 given)
>>> my_mock_func(1, 2, 3)
'I am a mock'