我能够查询restapi数据并转换为rdd和dataframe。但是当我尝试查询列时，得到的是逗号分隔的值，而不是列结果。
我错过什么了吗？
代码：

package Stream
import org.apache.spark.sql._
import org.apache.hadoop.conf.Configuration
import org.apache.hadoop.fs._
import org.apache.http.client.methods.HttpGet
import org.apache.http.impl.client.DefaultHttpClient
import org.apache.spark.sql.{DataFrame, SaveMode, SparkSession}
import org.apache.spark.sql.functions._
import org.apache.spark.sql.types.StructType
import org.apache.log4j.{Level, Logger}
import org.apache.spark.rdd.RDD
import org.apache.spark.sql.types._
import org.apache.spark.storage.StorageLevel

object SparkRestApi {
  def main(args: Array[String]): Unit = {

    val logger = Logger.getLogger("blah")
    Logger.getLogger("org").setLevel(Level.WARN)
    Logger.getLogger("akka").setLevel(Level.WARN)

    val spark = SparkSession.builder()
      .appName("blah")
      .config("spark.driver.memory", "2g")
      .master("local[*]")
      //.enableHiveSupport()
      .getOrCreate()

    import spark.implicits._

    val url = "https://platform-api.opentargets.io/v3/platform/public/association/filter"
    val result2 = List(scala.io.Source.fromURL(url).mkString)
    val githubRdd2=spark.sparkContext.makeRDD(result2)
    val gitHubDF2=spark.read.json(githubRdd2)
    gitHubDF2.show()
    val mediandf= gitHubDF2.select(col("data.association_score.overall").as("association_score"))
    mediandf.show()

    spark.stop()
  }

}

但结果格式不好。它是逗号分隔的，而不是格式良好的行中的值。

association_score|
|[1.0, 1.0, 1.0, 1...|

但我期待着

1.0
    1.0
    1.0