Error when creating UnionRDD of PairRDDs

rdd1 = sc.parallelize([1,2,3,4,5])
rdd2 = sc.parallelize([6,7,8,9,10])
pairRDD1 = rdd1.zip(rdd2)
unionRDD1 = sc.union([pairRDD1, pairRDD1])

Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/gs/spark/latest/python/pyspark/context.py", line 870,
in union jrdds[i] = rdds[i]._jrdd
File "/home/gs/spark/latest/python/lib/py4j-0.10.9-src.zip/py4j/java_collections.py", line 238, in _setitem_ File "/home/gs/spark/latest/python/lib/py4j-0.10.9-src.zip/py4j/java_collections.py", line 221,
in __set_item File "/home/gs/spark/latest/python/lib/py4j-0.10.9-src.zip/py4j/protocol.py", line 332, in get_return_value py4j.protocol.Py4JError: An error occurred while calling None.None. Trace: py4j.Py4JException: Cannot convert org.apache.spark.api.java.JavaPairRDD to org.apache.spark.api.java.JavaRDD at py4j.commands.ArrayCommand.convertArgument(ArrayCommand.java:166) at py4j.commands.ArrayCommand.setArray(ArrayCommand.java:144) at py4j.commands.ArrayCommand.execute(ArrayCommand.java:97) at py4j.GatewayConnection.run(GatewayConnection.java:238) at java.lang.Thread.run(Thread.java:748)

rdd3 = sc.parallelize([11,12,13,14,15])
pairRDD2 = rdd3.zip(rdd3)
unionRDD2 = sc.union([pairRDD1, pairRDD2])

Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/gs/spark/latest/python/pyspark/context.py", line 870, in union jrdds[i] = rdds[i]._jrdd File "/home/gs/spark/latest/python/lib/py4j-0.10.9-src.zip/py4j/java_collections.py", line 238, in _setitem_ File "/home/gs/spark/latest/python/lib/py4j-0.10.9-src.zip/py4j/java_collections.py", line 221, in __set_item File "/home/gs/spark/latest/python/lib/py4j-0.10.9-src.zip/py4j/protocol.py", line 332, in get_return_value py4j.protocol.Py4JError: An error occurred while calling None.None. Trace: py4j.Py4JException: Cannot convert org.apache.spark.api.java.JavaPairRDD to org.apache.spark.api.java.JavaRDD at py4j.commands.ArrayCommand.convertArgument(ArrayCommand.java:166) at py4j.commands.ArrayCommand.setArray(ArrayCommand.java:144) at py4j.commands.ArrayCommand.execute(ArrayCommand.java:97) at py4j.GatewayConnection.run(GatewayConnection.java:238) at java.lang.Thread.run(Thread.java:748)

rdd4 = sc.parallelize(range(5))
pairRDD3 = rdd4.zip(rdd4)
unionRDD3 = sc.union([pairRDD1, pairRDD3])
unionRDD3.collect()

[(1, 6), (2, 7), (3, 8), (4, 9), (5, 10), (0, 0), (1, 1), (2, 2), (3, 3), (4, 4)]