How to escape ( parentheses in Spark Scala?

Question

I am trying to replace parentheses in a string (i.e. column names). It is working fine with white spaces but not with ( parentheses. I tried """, \(, \\( but I am always getting an error. I also tried this tip How can I escape special symbols in scala string? but it did not help me. Can you please tell me how to solve this?

import org.apache.commons.lang3.StringEscapeUtils

var newDf = df
  for(col <- df.columns){
    newDf = newDf.withColumnRenamed(col,col.replaceAll(StringEscapeUtils.escapeJava("("), "_"))
    newDf = newDf.withColumnRenamed(col,col.replaceAll(" ", "-"))
}

Thanks a lot!

Answer 1

replaceAll uses regex, so you can just put parenthesis in a character class by which you don't have escape them:

val df = Seq((1,2)).toDF("(ABC)", "C D")

df.columns
// res28: Array[String] = Array((ABC), C D)

var newDf = df
for(col <- df.columns){
    newDf = newDf.withColumnRenamed(col, col.replaceAll(" ", "-").replaceAll("[()]", "_"))
}

newDf.columns
// res30: Array[String] = Array(_ABC_, C-D)

Or \\(|\\) should also work:

newDf.withColumnRenamed(col, col.replaceAll(" ", "-").replaceAll("\\(|\\)", "_"))