RDD编程练习
一、filter,map,flatmap练习:
1.读文本文件生成RDD lines
代码:lines = sc.textFile('file:///home/hadoop/word.txt')
2.将一行一行的文本分割成单词 words
代码:words=lines.flatMap(lambda line:line.split())
words.collect()
3.全部转换为小写
代码:#lines.flatMap(lambda line:line.lower().split()).collect()
words=lines.flatMap(lambda line:line.lower().split()).collect()
4.去掉长度小于3的单词
5.去掉停用词
准备停用词文本
代码:
1.准备停用词文本:
lines = sc.textFile('file:///home/hadoop/stopwords.txt')
stop = lines.flatMap(lambda line : line.split()).collect()
2.去除停用词:
words=lines.flatMap(lambda line:line.lower().split()).filter(lambda word : word not in stopword.txt)
words.collect()
二、groupByKey练习
6.练习一的生成单词键值对
代码:words.map(lambda word : (word,1))
7.对单词进行分组
代码:words.map(lambda word : (word,1)).groupByKey()
8.查看分组结果