gistfile1.py

class ExTestCase(TestCase):
    def assertRaisesMessage(self, expected_exception, expected_message,
                           callable_obj=None, *args, **kwargs):
        """
        Asserts that the message in a raised exception matches the passed
        value.

        Args:
            expected_exception: Exception class expected to be raised.
            expected_message: expected error message string value.
            callable_obj: Function to be called.
            args: Extra args.
            kwargs: Extra kwargs.
        """
        try:
            callable_obj(*args,**kwargs)
        except Exception, err:
            self.assertTrue(isinstance(err,expected_exception),u"Raise something unexpected!")
            self.assertEquals(err.message,expected_message)

        return True