在scala中向数据框添加百分比符号并写入excel答案

【问题标题】：Adding Percentage sign to dataframe in scala and writing to excel在scala中向数据框添加百分比符号并写入excel
【发布时间】：2021-02-08 18:25:08
【问题描述】：

我想使用 scala 将数据框写入 excel。

    val noErrors = 20000
    val total = 1000
    val emails = Seq(
      (1, "first", noErrors/100),
      (2, "SPAM SPAM spam", total),
      (3, "Hello, We'd like to", noErrors)
    ).toDF("id", "text","text2")
      .withColumn("text2",
        when($"text2" === lit(-1.0), lit(null)  )
          .otherwise(round($"text2", 1)))
      .orderBy($"id".asc)
      .drop("id")
    emails.show()

我正在尝试将 % 符号添加到“noErrors/100”。没有任何条件，它可以正常工作，但是当我添加条件列时，它会出错。

【问题讨论】：

标签： scala dataframe apache-spark-sql

【解决方案1】：

import org.apache.spark.sql.functions._
val noErrors = 20000
    val total = 1000
    val emails = Seq(
      (1, "first", noErrors/100),
      (2, "SPAM SPAM spam", total),
      (3, "Hello, We'd like to", noErrors)
    ).toDF("id", "text","text2")
      .withColumn("text2",
        when($"text2" === lit(-1.0), lit(null)  )
          .otherwise(round($"text2", 1)))
      .orderBy($"id".asc)
      .drop("id")

val df = emails.withColumn("text2", when(col("text") === "first","200%") )
df.show()

输出：

+-------------------+-----+
|               text|text2|
+-------------------+-----+
|              first| 200%|
|     SPAM SPAM spam| null|
|Hello, We'd like to| null|
+-------------------+-----+

import org.apache.spark.sql.functions._
noErrors: Int = 20000
total: Int = 1000
emails: org.apache.spark.sql.DataFrame = [text: string, text2: int]
df: org.apache.spark.sql.DataFrame = [text: string, text2: string]

这是你想要的吗？

【讨论】：