def intersect_rdds(rdd1, rdd2):
  """
  Returns a RDD being the intersection of both rdds, equivalent to a SQL inner join
  The condition used for the join here is the first column of the original RDDs
  """
  rdd1 = sc.parallelize([((0,0), 1), ((0,1), 2), ((1,0), 3), ((1,1), 4)])
  rdd2 = sc.parallelize([((0,1), 3), ((1,1), 0)])
  return rdd1.cogroup(rdd2).filter(lambda x: x[1][0] and x[1][1])