python利用M/R实现wordcount

Map阶段

#!/usr/bin/python
import sys
for line in sys.stdin:
    line = line.strip()
    words = line.split()
    for word in words:
        print("{} {}".format(word,1))

Reduce阶段

#!/usr/bin/python
import sys

current_word = None
current_count = 0

for line in sys.stdin:
    line = line.strip()
    word, count = line.split('\t', 1)
    try:
        count = int(count)
    except ValueError:  #count如果不是数字的话，直接忽略掉
        continue
    if current_word == word:
        current_count += count
    else:
        if current_word:
            print("{} {}".format(current_word, current_count))
        current_count = count
        current_word = word

if word == current_word:  #不要忘记最后的输出

　　print("{} {}".format(current_word, current_count))