[MapReduce] Find the time (in hours) for each user's favorite PO sticker

From Udacity,intro to Hadoop, final Project.
The topic requests, from the forum Post's structured data, discovers each user po pastes the most time. For example, user A at 8 points per day, po the most posts, the number marked as X so reducer output is a X
Train of thought: Mapper need to output author_id, reducer to each user to do a {Hour:count} statistics, the last output of the most count hour

#mapper
#!/usr/bin/python

import sys
import csv

reader = Csv.reader (Sys.stdin, delimiter = "\ T")
Next (reader, None) for line in

reader:
    If len (line) = =
        author_id = line[3]
        hour = line[8][11:13]

        print ' {0}\t{1} '. Format (author_id, hour)


# reducer
#!/usr/bin/python

import sys



oldid = None

hours = {} for

I in range:
    hours[i] = 0 for line in

Sys.stdin:

    data = Line.strip (). Split ("\ t ")
    If len (data) = = 2:
        Thisauthorid, hour = data

        if oldid and oldid!= thisauthorid:
            print" {0}\t{1} ". f Ormat (oldid, max (hours, key=hours.get))
            oldid = Thisauthorid for
            i in Range (a):
                hours[i] = 0

        oldid = Thisauthorid
        Hours[int (hour)] + + 1

if oldid!= None:
    print "{0}\t{1}". Format (oldid, Max (hours, key= Hours.get))