Lists differ: [[(1,[96 chars]1]))], [('', ([1, 1], [1, 2])), ('a', ([1, 1],[25 chars]]))]] != [[(1,[96 chars]1]))]] First list contains 1 additional elements. First extra element 2: [('', ([1, 1], [1, 2])), ('a', ([1, 1], [1, 1])), ('b', ([1], [1]))] [[(1, ([1], [2])), (2, ([1], [])), (3, ([1], []))], - [(1, ([1, 1, 1], [])), (2, ([1], [])), (4, ([], [1]))], ? ^ + [(1, ([1, 1, 1], [])), (2, ([1], [])), (4, ([], [1]))]] ? ^ - [('', ([1, 1], [1, 2])), ('a', ([1, 1], [1, 1])), ('b', ([1], [1]))]]

Traceback (most recent call last):
  File "/home/jenkins/workspace/spark-master-test-sbt-hadoop-2.4/python/pyspark/streaming/tests.py", line 349, in test_cogroup
    self._test_func(input, func, expected, sort=True, input2=input2)
  File "/home/jenkins/workspace/spark-master-test-sbt-hadoop-2.4/python/pyspark/streaming/tests.py", line 160, in _test_func
    self.assertEqual(expected, result)
AssertionError: Lists differ: [[(1,[96 chars]1]))], [('', ([1, 1], [1, 2])), ('a', ([1, 1],[25 chars]]))]] != [[(1,[96 chars]1]))]]

First list contains 1 additional elements.
First extra element 2:
[('', ([1, 1], [1, 2])), ('a', ([1, 1], [1, 1])), ('b', ([1], [1]))]

  [[(1, ([1], [2])), (2, ([1], [])), (3, ([1], []))],
-  [(1, ([1, 1, 1], [])), (2, ([1], [])), (4, ([], [1]))],
?                                                        ^

+  [(1, ([1, 1, 1], [])), (2, ([1], [])), (4, ([], [1]))]]
?                                                        ^

-  [('', ([1, 1], [1, 2])), ('a', ([1, 1], [1, 1])), ('b', ([1], [1]))]]

Stdout:
('timeout after', 10)