test_fileinput.py 文件源码

def test_state_is_not_None(self):
        """Tests fileinput.filename() when fileinput._state is not None.
           Ensure that it invokes fileinput._state.filename() exactly once,
           returns whatever it returns, and does not modify fileinput._state
           to point to a different object."""
        filename_retval = object()
        instance = MockFileInput()
        instance.return_values["filename"] = filename_retval
        fileinput._state = instance
        retval = fileinput.filename()
        self.assertExactlyOneInvocation(instance, "filename")
        self.assertIs(retval, filename_retval)
        self.assertIs(fileinput._state, instance)