CODEWITHSUNDEEP
apache-sparkmapreducepysparkapache-spark-sqlouter-join
Arij SEDIRI
Arij SEDIRI

Reputation: 2158

How to do properly a full Outer Join of two RDDs with PySpark?

I'm looking for a way to combine two RDDs by key.

Given :

x = sc.parallelize([('_guid_YWKnKkcrg_Ej0icb07bhd-mXPjw-FcPi764RRhVrOxE=', 'FR', '75001'),
                ('_guid_XblBPCaB8qx9SK3D4HuAZwO-1cuBPc1GgfgNUC2PYm4=', 'TN', '8160'),
               ]
              )
y = sc.parallelize([('_guid_oX6Lu2xxHtA_T93sK6igyW5RaHH1tAsWcF0RpNx_kUQ=', 'JmJCFu3N'),
                ('_guid_hG88Yt5EUsqT8a06Cy380ga3XHPwaFylNyuvvqDslCw=', 'KNPQLQth'),
                ('_guid_YWKnKkcrg_Ej0icb07bhd-mXPjw-FcPi764RRhVrOxE=', 'KlGZj08d'),
               ]
              )

I found a solution ! Nevertheless, this solution is not entirely satisfactory for what I want to do. I created a function in order to specify my key which will be applied to my rdd named "x" :

def get_keys(rdd):

    new_x = rdd.map(lambda item: (item[0], (item[1], item[2])))
    return new_x

new_x = get_keys(x)

which gives :

[('_guid_YWKnKkcrg_Ej0icb07bhd-mXPjw-FcPi764RRhVrOxE=', ('FR', '75001')),
 ('_guid_XblBPCaB8qx9SK3D4HuAZwO-1cuBPc1GgfgNUC2PYm4=', ('TN', '8160'))]

Then :

new_x.union(y).map(lambda (x, y): (x, [y])).reduceByKey(lambda p, q : p + q).collect()

The result :

[('_guid_oX6Lu2xxHtA_T93sK6igyW5RaHH1tAsWcF0RpNx_kUQ=', ['JmJCFu3N']),
 ('_guid_YWKnKkcrg_Ej0icb07bhd-mXPjw-FcPi764RRhVrOxE=', [('FR', '75001'), 'KlGZj08d']),
 ('_guid_XblBPCaB8qx9SK3D4HuAZwO-1cuBPc1GgfgNUC2PYm4=', [('TN', '8160')]),
 ('_guid_hG88Yt5EUsqT8a06Cy380ga3XHPwaFylNyuvvqDslCw=', ['KNPQLQth'])]

What I want to have is :

[('_guid_oX6Lu2xxHtA_T93sK6igyW5RaHH1tAsWcF0RpNx_kUQ=', (None, None, 'JmJCFu3N')),
 ('_guid_YWKnKkcrg_Ej0icb07bhd-mXPjw-FcPi764RRhVrOxE=', ('FR', '75001', 'KlGZj08d')),
 ('_guid_XblBPCaB8qx9SK3D4HuAZwO-1cuBPc1GgfgNUC2PYm4=', ('TN', '8160', None)),
 ('_guid_hG88Yt5EUsqT8a06Cy380ga3XHPwaFylNyuvvqDslCw=', (None, None, 'KNPQLQth'))]

Help ?

Upvotes: 2

Views: 7103

Answers (1)

user6022341
user6022341

Reputation:

Why not?

>>> new_x.fullOuterJoin(y)

or 

>>> x.toDF().join(y.toDF(), ["_1"], "fullouter").rdd

Upvotes: 2

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