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

Creating DataFrames


Spark DataFrame creation is similar to RDD creation. To get access to the DataFrame API, you need SQLContext or HiveContext as an entry point. In this section, we are going to demonstrate how to create DataFrames from various data sources, starting from basic code examples with in-memory collections:

Creating DataFrames from RDDs

The following code creates an RDD from a list of colors followed by a collection of tuples containing the color name and its length. It creates a DataFrame using the toDF method to convert the RDD into a DataFrame. The toDF method takes a list of column labels as an optional argument:

Python:

   //Create a list of colours 
>>> colors = ['white','green','yellow','red','brown','pink'] 
//Distribute a local collection to form an RDD 
//Apply map function on that RDD to get another RDD containing colour, length tuples 
>>> color_df = sc.parallelize(colors) 
        .map(lambda x:(x,len(x))).toDF(["color","length"]) 
 
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