CODEWITHSUNDEEP
scalahadoopapache-sparkpysparkrdd
Muhammed Eltabakh
Muhammed Eltabakh

Reputation: 497

How can I zip two RDDs in PySpark?

I have been trying to merge the two Rdds below averagePoints1 and kpoints2 . It keeps throwing this error 

ValueError: Can not deserialize RDD with different number of items in pair: (2, 1)

and I tried many things but I can't the two Rdds are identical, have the same number of partitions . my next to step is to apply euclidean distance function on the two lists to measure the difference so if any one knows how to solve this error or has a different approach I can follow I would really appreciate it.

Thanks in advance

 averagePoints1 = averagePoints.map(lambda x: x[1])
 averagePoints1.collect()
 Out[15]:
 [[34.48939954847243, -118.17286894440112],
 [41.028994230117945, -120.46279399895184],
 [37.41157578999635, -121.60431843383599],
 [34.42627845075509, -113.87191272382309],
 [39.00897622397381, -122.63680410846844]] 

  kpoints2 = sc.parallelize(kpoints,4)
  In [17]:

  kpoints2.collect()
  Out[17]:
  [[34.0830381107, -117.960562808],
  [38.8057258629, -120.990763316],
  [38.0822414157, -121.956922473],
  [33.4516748053, -116.592291648],
  [38.1808762414, -122.246825578]]

Upvotes: 3

Views: 6043

Answers (2)

Muhammed Eltabakh
Muhammed Eltabakh

Reputation: 497

newSample=newCenters.collect() #new centers as a list
    samples=zip(newSample,sample) #sample=> old centers
    samples1=sc.parallelize(samples)
    totalDistance=samples1.map(lambda (x,y):distanceSquared(x[1],y))

for future searchers this is the solution I followed at the end

Upvotes: 0

ling7334
ling7334

Reputation: 454

a= [[34.48939954847243, -118.17286894440112],
 [41.028994230117945, -120.46279399895184],
 [37.41157578999635, -121.60431843383599],
 [34.42627845075509, -113.87191272382309],
 [39.00897622397381, -122.63680410846844]] 
b= [[34.0830381107, -117.960562808],
  [38.8057258629, -120.990763316],
  [38.0822414157, -121.956922473],
  [33.4516748053, -116.592291648],
  [38.1808762414, -122.246825578]]

rdda = sc.parallelize(a)
rddb = sc.parallelize(b)
c = rdda.zip(rddb)
print(c.collect())

check this answer Combine two RDDs in pyspark

Upvotes: 3

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