For the python2 version the final part of the code stub needs to be corrected to:

if __name__ == '__main__':
    N = 0
    inputData = []
    counter = 0
    for line in sys.stdin:
        if counter > 0:
            inputData.append(json.dumps({"key":counter,"value":int(line.strip())}))
        counter += 1
    mapReducer.execute(inputData, mapper, reducer)

Hi this's really Excellent exercise for completing the series... you're awesome..

Thanks guys Buzz CNN

Excellent exercise to finish the series! Here it's a "pure" mapping exercise at the contrary of previous ones: reduce() does nothing.

This didn't really force me to understand how this worked, I just saw the expected parameters...