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 [英] Dropping multiple columns from Spark dataframe by Iterating through the columns from a Scala List of Column names

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)): _*) 

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