如何重命名scala数据框中的列标题

withColumnRenamed仅重命名列名称，数据保持不变。如果需要更改行上下文，可以使用以下方法之一：

import sparkSession.implicits._
import org.apache.spark.sql.functions._

val inputDf = Seq("to_be", "misc").toDF("c1")
val resultd1Df = inputDf
.withColumn("c2", regexp_replace($"c1", "^to_be$", "not_to_be"))
.select($"c2".as("c1"))
resultd1Df.show()

val resultd2Df = inputDf
.withColumn("c2", when($"c1" === "to_be", "not_to_be").otherwise($"c1"))
.select($"c2".as("c1"))
resultd2Df.show()

def replace(mapping: Map[String, String]) = udf(
(from: String) => mapping.get(from).orElse(Some(from))
)

val resultd3Df = inputDf
.withColumn("c2", replace(Map("to_be" -> "not_to_be"))($"c1"))
.select($"c2".as("c1"))
resultd3Df.show()
输入数据帧：

结果数据框：