通过迭代列名称的Scala列表中的列从Spark数据框中删除多个列

问题描述

我有一个数据列，该列的列数约为400，我想根据需要删除100列.所以我创建了一个100列名称的Scala列表.然后，我想遍历for循环，以实际删除每个for循环迭代中的列.

I have a dataframe which has columns around 400, I want to drop 100 columns as per my requirement.So i have created a Scala List of 100 column names.And then i want to iterate through a for loop to actually drop the column in each for loop iteration.

下面是代码.

final val dropList: List[String] = List("Col1","Col2",...."Col100")

def drpColsfunc(inputDF: DataFrame): DataFrame = { 
    for (i <- 0 to dropList.length - 1) {
        val returnDF = inputDF.drop(dropList(i))
    }
    return returnDF
}

val test_df = drpColsfunc(input_dataframe) 

test_df.show(5)

推荐答案

答案:

val colsToRemove = Seq("colA", "colB", "colC", etc) 

val filteredDF = df.select(df.columns .filter(colName => !colsToRemove.contains(colName)) .map(colName => new Column(colName)): _*) 

这篇关于通过迭代列名称的Scala列表中的列从Spark数据框中删除多个列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！