Spark RDD编程

Spark RDD编程

 

1.

准备文本文件
从文件创建RDD lines=sc.textFile()
筛选出含某个单词的行 lines.filter()
lambda 参数：条件表达式

lines = sc.textFile("file:///usr/local/spark/mycode/rdd/word.txt")
linesWithSpark = lines.filter(lambda line:"time" in line)
linesWithSpark.foreach(print)

2.

生成单词的列表
从列表创建RDD words=sc.parallelize()
筛选出长度大于2 的单词 words.filter()

wordsList='In a fairly short time'.split()
wordsList
wordsRDD=sc.parallelize(wordsList)
wordsRDD.collect()
wordsRDD.filter(lambda word:len(word)>2).collect()

 

 3.

 筛选出的单词RDD，映射为（单词，1）键值对。 words.map()

 

wordsRDD.map(lambda word:(word,1)).collect()