!/usr/bin/python

import sys

# Input takes from standard input for myline in sys.stdin: 
   # Remove whitespace either side 
   myline = myline.strip() 

   # Break the line into words 
   words = myline.split() 

   # Iterate the words list
   for myword in words:
      # Write the results to standard output 
      print '%s\t%s' % (myword, 1)

#!/usr/bin/python

from operator import itemgetter 
import sys 

current_word = ""
current_count = 0 
word = "" 

# Input takes from standard input for myline in sys.stdin: 
   # Remove whitespace either side 
   myline = myline.strip() 

   # Split the input we got from mapper.py word, 
   count = myline.split('\t', 1) 

   # Convert count variable to integer 
   try: 
      count = int(count) 

   except ValueError: 
      # Count was not a number, so silently ignore this line continue

   if current_word == word: 
   current_count += count 
   else: 
      if current_word: 
         # Write result to standard output print '%s\t%s' % (current_word, current_count) 
   
      current_count = count
      current_word = word

# Do not forget to output the last word if needed! 
if current_word == word: 
   print '%s\t%s' % (current_word, current_count)

$ $HADOOP_HOME/bin/hadoop jar contrib/streaming/hadoop-streaming-1.
2.1.jar \
   -input input_dirs \ 
   -output output_dir \ 
   -mapper 

./bin/hadoop jar contrib/streaming/hadoop-streaming-1.2.1.jar -input myinput -output myoutput -mapper /home/expert/hadoop-1.2.1/mapper.py -reducer /home/expert/hadoop-1.2.1/reducer.py