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我正在努力为谷歌书籍的ngrams建立一个mapreduce工作。我的mapper在本地测试时工作正常,但reducer没有返回任何值。减速机是类似下面的东西:python ngram reducer没有返回任何输出?
#! /usr/bin/env python
import sys
current_word = ''
word_in_progress = ''
target_year_count = 0
prior_year_count = 0
target_year = 1999
for line in sys.stdin:
line = line.strip().split('\t')
if len(line) !=3:
continue
current_word, year, occurances = line
if current_word != word_in_progress:
if target_year_count > 0:
if prior_year_count ==0:
print '%s\t%s' % (word_in_progress, target_year_count)
try:
year = int(year)
except ValueError:
continue
try:
occurances = int(occurances)
except ValueError:
continue
if year == target_year:
target_year_count += occurances
if year < target_year:
prior_year_count += occurances
print '%s\t%s' % (word_in_progress, target_year_count)
if target_year_count > 0:
if prior_year_count ==0:
print '%s\t%s' % (word_in_progress, target_year_count)
当我键入Ubuntu的命令行下面的命令:
[email protected]:~/hadoop$ cat /home/hduser/Documents/test1.1.txt | /home/hduser /hadoop/mapper-ngram.py | sort -k1,1 | /home/hduser/hadoop/reducerngram1.py| sort -k2,2n
我什么也没得到。有人能告诉我我正在做什么错。