将2D列表保存到数据框Scala Spark中

Question

I have a 2d list of the following format with the name tuppleSlides:

List(List(10,4,2,4,5,2,6,2,5,7), List(10,4,2,4,5,2,6,2,5,7), List(10,4,2,4,5,2,6,2,5,7), List(10,4,2,4,5,2,6,2,5,7))

I have created the following schema:

val schema = StructType(
            Array(
            StructField("1", IntegerType, true), 
            StructField("2", IntegerType, true), 
            StructField("3", IntegerType, true), 
            StructField("4", IntegerType, true),  
            StructField("5", IntegerType, true), 
            StructField("6", IntegerType, true), 
            StructField("7", IntegerType, true), 
            StructField("8", IntegerType, true), 
            StructField("9", IntegerType, true), 
            StructField("10", IntegerType, true) )
        )

and I am creating a dataframe like so:

val tuppleSlidesDF = sparkSession.createDataFrame(tuppleSlides, schema)

but it won't even compile. How am I suppose to do it properly?

Thank you.

Answer 1

You need to convert the 2d list to a RDD[Row] object before creating a data frame:

import org.apache.spark.sql._
import org.apache.spark.sql.types._

val rdd = sc.parallelize(tupleSlides).map(Row.fromSeq(_))

sqlContext.createDataFrame(rdd, schema)
# res7: org.apache.spark.sql.DataFrame = [1: int, 2: int, 3: int, 4: int, 5: int, 6: int, 7: int, 8: int, 9: int, 10: int]

---

Also note in spark 2.x, sqlContext is replaced with spark :

spark.createDataFrame(rdd, schema)
# res1: org.apache.spark.sql.DataFrame = [1: int, 2: int ... 8 more fields]