读取文件火花，将具有特定值的字段设置为空或“"； [英] Read File spark, set field having specific value to null or ""

问题描述

我正在阅读以 | 分隔的文本文件.有一些字段具有值 \N .当逐行读取文件到数据帧时，是否有任何方法可以使具有值 \N 的字段为 null 或 "" .代码如下.

I'm Reading a text file delimited with | . There are some fields having value \N . When read the file row by row to a data-frame, is there any way to make the field having value \N to null or "" . Code is given below.

val inputDf = sqlContext.read.format("csv")
      .option("header", "true")
      .option("inferSchema", "false")
      .schema(myschema)
      .option("delimiter", "|")
      .option("nullValue", "")
      .load("My Input file Path")

推荐答案

"DataFrameNaFunctions" 可用于将所有列中的值 "\N" 替换为 "":

"DataFrameNaFunctions" can be used for replace value "\N" in all columns with "":

df.na.replace(df.columns.toSeq, Map("\\N" -> ""))

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