x = sc.parallelize([("a", 1), ("b", 4)])
y = sc.parallelize([("a", 2)])
sorted(x.leftOuterJoin(y).collect())
# [('a', (1, 2)), ('b', (4, None))]
x = sc.parallelize([("a", 1), ("b", 4)])
y = sc.parallelize([("a", 2)])
sorted(y.rightOuterJoin(x).collect())
# [('a', (2, 1)), ('b', (None, 4))]