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lambdapysparkrdd

Applying lambda functions across separate RDD objects

I have an rdd containing the values below.

rdd_2 = sc.parallelize([('f3.txt', 'of', 0.0),
 ('f3.txt',
  'no',
  0.00023241396735284342),
 ('f3.txt',
  'may',
  0.00042318717429693387),
 ('f3.txt',
  'love',
  0.00036660747046705975),
 ('f3.txt',
  'romantic',
  0.00022935755451437367)])

I wish to filter this RDD by the words ('romantic', 'love') using a lambda function such that my resulting output is:

([('f3.txt', 'of', 0),
 ('f3.txt',
  'no',
  0),
 ('f3.txt',
  'may',
  0),
 ('f3.txt',
  'love',
  1),
 ('f3.txt',
  'romantic',
  1)])

I have tried the following code but i get an error:

querylist = ['romantic', 'love']
q = rdd_2.map(lambda x : x[2]=1 if x[1] not in querylist else x[2]=0)

SyntaxError: invalid syntax

What should i do?

Solution

  • You can not assign values like that in a lambda function. Instead return a new object containing the modified values.

    Try this:

    querylist = ['romantic', 'love']
q = rdd_2.map(lambda x : (x[0], x[1], 1 if x[1] not in querylist else 0))

    Or equivalently;

    q = rdd_2.map(lambda x : (x[0], x[1], int(x[1] not in querylist)))