def test_v_date_invalid(self):
     """Test v_date validator with invalid dates"""
     # standard date format
     date_str = "2013_44_01"
     with self.assertRaises(ValueError):
         v_date(date_str)
     # with different date format
     date_str = "2013-44-01"
     with self.assertRaises(ValueError):
         v_date(date_str)
 def test_v_date_valid(self):
     """Test v_date validator with valid dates"""
     # standard date format
     date_str = "2013_03_01"
     self.assertEqual(v_date(date_str), dt.datetime(2013, 3, 1))
     date_obj = dt.datetime(2013, 3, 1)
     self.assertEqual(v_date(date_obj), date_obj)
     # with different date format
     date_str = "2013-03-01"
     self.assertEqual(v_date(date_str, format="%Y-%m-%d"),
                      dt.datetime(2013, 3, 1))