Question

Modify your mapper to count the number of occurrences of each character (including punctuation marks) in the file.

#!/usr/bin/env python

#the above just indicates to use python to intepret this file

#This mapper code will input a line of text and output <word, 1> #

import sys

sys.path.append('.')

for line in sys.stdin:

line = line.strip() #trim spaces from beginning and end

keys = line.split() #split line by space

for key in keys:

value = 1

print ("%s\t%d" % (key,value)) #for each word generate 'word TAB 1' line

Answer 1

If you have any doubts, please give me comment...

#!/usr/bin/env python

inp_fname = input("Enter input filename: ")

fp = open(inp_fname)

occurances = {}

for line in fp.readlines():

    line = line.strip() #trim spaces from beginning and end

    for ch in line:

        if ch not in occurances:

            occurances[ch] = 0

        occurances[ch] += 1

fp.close()

print("Char\tCount")

for ch in occurances:

    print(ch+"\t"+str(occurances[ch]))