How to overwrite the rdd saveAsPickleFile(path) if file already exist in pyspark?

问题

How to overwrite RDD output objects any existing path when we are saving time.

test1:

975078|56691|2.000|20171001_926_570_1322
975078|42993|1.690|20171001_926_570_1322
975078|46462|2.000|20171001_926_570_1322
975078|87815|1.000|20171001_926_570_1322

rdd=sc.textFile('/home/administrator/work/test1').map( lambda x: x.split("|")[:4]).map( lambda r: Row( user_code = r[0],item_code = r[1],qty = float(r[2])))
rdd.coalesce(1).saveAsPickleFile("/home/administrator/work/foobar_seq1")

The first time it is saving properly. now again I removed one line from the input file and saving RDD same location, it show file has existed.

rdd.coalesce(1).saveAsPickleFile("/home/administrator/work/foobar_seq1") 

For example, in dataframe we can overwrite existing path.

df.coalesce(1).write().overwrite().save(path)

If I am doing same on RDD object getting an error.

rdd.coalesce(1).write().overwrite().saveAsPickleFile(path)

please help me on this

回答1:

Hi you can save RDD files like below Note (code is in scala but logic should be same for python as well) i am using 2.3.0 spark version.

  val sconf = new SparkConf().set("spark.hadoop.validateOutputSpecs", "False").setMaster("local[*]").setAppName("test")
  val scontext = new SparkContext(sconf)
  val lines = scontext.textFile("C:\\Users\\...\\Desktop\\Sampledata.txt", 1)
    println(lines.first)
    lines.saveAsTextFile("C:\\Users\\...\\Desktop\\sample2")

or if ur working with DataFrame then use

DF.write.mode(SaveMode.Overwrite).parquet(path.parquet")

or for more info please look at this

回答2:

While, the rdd without write mode, and you can convert rdd to df , using df overwrite mode. As follows:

df.coalesce(1).toDF().map(lambda x: (x,)).write.csv(path=yourpath, mode='overwrite')

来源：https://stackoverflow.com/questions/49528893/how-to-overwrite-the-rdd-saveaspicklefilepath-if-file-already-exist-in-pyspark