Spark：如何将RDD [（Long，Iterable [String]）]转换为RDD [（Long，String）]？

Question

如何转换这种RDD [（长，可迭代[字符串]）]以...

(852403,Set(PT0000094043, PT0000097083, PT0000036162)) 
(357331,Set(PT0000068829, PT0000094042, PT0000066859)) 

RDD [（长，字符串）]这样吗？

(852403, PT0000094043) 
(852403, PT0000097083) 
(852403, PT0000036162) 
(357331, PT0000068829) 
(357331, PT0000094042) 
(357331, PT0000066859) 

Answer 1

尝试flatMapValues：

rdd.flatMapValues(identity) 

或flatMap：

rdd.flatMap{ case (k, vs) => vs.map(v => (k, v)) }