Apache Spark 2.x Machine Learning Cookbook

Transforming RDDs with the super useful flatMap() API

In this recipe, we examine the flatMap() method which is often a source of confusion for beginners; however, on closer examination we demonstrate that it is a clear concept that applies the lambda function to each element just like map, and then flattens the resulting RDD as a single structure (rather than having a list of lists, we create a single list made of all sublist with sublist elements).