pyspark and reduceByKey: how to make a simple sum

Question

I am trying some code in Spark (pyspark) for an assignment. First time I use this environment, so for sure I miss something…

I have a simple dataset called c_views.

Answer 1

Other simple ways to achieve the result?

from operator import add 

c_views.reduceByKey(add)

or if you prefer lambda expressions:

c_views.reduceByKey(lambda x, y: x + y)

I do not understand what exactly I have to code in the function

It has to be a function which takes two values of the same types as the values in your RDD and returns a value of the same type as inputs. It also has to be associative which means that the final result cannot depend how do you arrange parentheses.