How to create DataFrame from Scala's List of Iterables?

Question

I have the following Scala value:

val values: List[Iterable[Any]] = Traces().evaluate(features).toList

and I want to convert it to a DataFrame.

When I try the following:

sqlContext.createDataFrame(values)

I got this error:

error: overloaded method value createDataFrame with alternatives:

[A <: Product](data: Seq[A])(implicit evidence$2: reflect.runtime.universe.TypeTag[A])org.apache.spark.sql.DataFrame
[A <: Product](rdd: org.apache.spark.rdd.RDD[A])(implicit evidence$1: reflect.runtime.universe.TypeTag[A])org.apache.spark.sql.DataFrame
cannot be applied to (List[Iterable[Any]])
          sqlContext.createDataFrame(values)
 

Answer 1

You just need to first convert List[Iterable[Any]] to List[Row] and then put rows in RDD and prepare schema for the spark data frame.

To convert List[Iterable[Any]] to List[Row], we can say

val rows = values.map{x => Row(x:_*)}

and then having schema like schema, we can make RDD

val rdd = sparkContext.makeRDD[RDD](rows)

and finally create a spark data frame

val df = sqlContext.createDataFrame(rdd, schema)