Unittest for IOError exception handling

Given this code:

 try:
        #do something
 except IOError as message:
        logging.error(message)
        raise message

I want to test the exception handling part in order to have full coverage. In the unittest I've tried with:

        with patch(new=Mock(side_effect=IOError(errno.EIO))):
            self.assertRaises(IOError)

but it doesnt work. Is this approach correct?