如何在不使用map reduce的情况下使用Python编写单词计数程序

Question

Actually im new to hadoop and also to python .... So my doubt is how to run a python script in hadoop..... And also i was writing a wordcount program using python..So, can we execute this script without using the map reduce.... Actually i wrote the code i can see the output as below Darkness 1 Heaven 2 It 3 Light 4 age 5 age 6 all 7 all 8 authorities 9 before 10 before 11 being 12 belief 13 best 14 comparison 15 degree 16 despair 17 direct 18 direct 19

It is counting number of words in a list..but whati have to achieve is grouping and deleting the duplicates and also count number of times of its occurrences  ..... 

Below is my code . can somebody please tell me where i have done the mistake

********************************************************
   Wordcount.py
********************************************************

import urllib2
import random
from operator import itemgetter

current_word = {}
current_count = 0
story = 'http://sixty-north.com/c/t.txt'
request = urllib2.Request(story)
response = urllib2.urlopen(request)
each_word = []
words = None
count = 1
same_words ={}
word = []
""" looping the entire file """
for line in response:
    line_words = line.split()
    for word in line_words:  # looping each line and extracting words
        each_word.append(word)
        random.shuffle(each_word)
        Sort_word = sorted(each_word)
for words in Sort_word:
    same_words = words.lower(),int(count)
    #print same_words
    #print words
    if not words in current_word :
        current_count = current_count +1
        print '%s\t%s' % (words, current_count)
    else:
        current_count = 1
        #if Sort_word == words.lower():
            #current_count += count
current_count = count
current_word = word
        #print '2. %s\t%s' % (words, current_count)

Answer 1

For running python Based MR tasks ,have a Look at:

http://hadoop.apache.org/docs/r1.1.2/streaming.html http://www.michael-noll.com/tutorials/writing-an-hadoop-mapreduce-program-in-python/

You need to design your code in Terms of Mapper - Reducer to enable Hadoop to execute your Python script. Read on the Map-Reduce Programming Paradigm before you can jump into writing the code. Its important to understand the MR programming paradigm and the role of {Key , value } pairs in solving the problem.

#Modified your above code to generate the required output
import urllib2
import random
from operator import itemgetter

current_word = {}
current_count = 0
story = 'http://sixty-north.com/c/t.txt'
request = urllib2.Request(story)
response = urllib2.urlopen(request)
each_word = []
words = None
count = 1
same_words ={}
word = []
""" looping the entire file """
#Collect All the words into a list
for line in response:
    #print "Line = " , line
    line_words = line.split()
    for word in line_words:  # looping each line and extracting words
        each_word.append(word)

#for every word collected, in dict same_words
#if a key exists, such that key == word then increment Mapping Value by 1
# Else add word as new key with mapped value as 1
for words in each_word:
    if words.lower() not in same_words.keys() :
        same_words[words.lower()]=1
    else:
        same_words[words.lower()]=same_words[words.lower()]+1

for each in same_words.keys():
    print "word = ",each, ", count = ",same_words[each]