Book Image

Spark for Data Science

By : Srinivas Duvvuri, Bikramaditya Singhal
Book Image

Spark for Data Science

By: Srinivas Duvvuri, Bikramaditya Singhal

Overview of this book

This is the era of Big Data. The words ‘Big Data’ implies big innovation and enables a competitive advantage for businesses. Apache Spark was designed to perform Big Data analytics at scale, and so Spark is equipped with the necessary algorithms and supports multiple programming languages. Whether you are a technologist, a data scientist, or a beginner to Big Data analytics, this book will provide you with all the skills necessary to perform statistical data analysis, data visualization, predictive modeling, and build scalable data products or solutions using Python, Scala, and R. With ample case studies and real-world examples, Spark for Data Science will help you ensure the successful execution of your data science projects.
Table of Contents (18 chapters)
Spark for Data Science
Credits
Foreword
About the Authors
About the Reviewers
www.PacktPub.com
Preface

DataFrame operations


In the previous section of this chapter, we learnt many different ways of creating DataFrames. In this section, we will focus on various operations that can be performed on DataFrames. Developers chain multiple operations to filter, transform, aggregate, and sort data in the DataFrames. The underlying Catalyst optimizer ensures efficient execution of these operations. These functions you find here are similar to those you commonly find in SQL operations on tables:

Python:

//Create a local collection of colors first 
>>> colors = ['white','green','yellow','red','brown','pink'] 
//Distribute the local collection to form an RDD 
//Apply map function on that RDD to get another RDD containing colour, length tuples and convert that RDD to a DataFrame 
>>> color_df = sc.parallelize(colors) 
        .map(lambda x:(x,len(x))).toDF(['color','length']) 
//Check the object type 
>>> color_df 
DataFrame[color: string, length: bigint] 
//Check the schema...