fail to use collect RDD

Question

Please does anyone knows what is the error in this line of code? Spend hours searching but didn't succeed to fix it. Thank youu in advance,

labels = RDD.map(lambda (a, b): a).collect()

Syntax error

Answer 1

If you are using python 3 probably it is about tuple unpacking that is not supported in python 3. Also you can check this thread .

Let's say you have rdd of tuples:

RDD = spark.sparkContext.range(0, 1).map(lambda a: (a, a))

below code will fail with SyntaxError: invalid syntax

RDD.map(lambda (a, b): a).collect()

but this will work correctly:

RDD.map(lambda a: a[0]).collect()