Book Image

Learning PySpark

By : Tomasz Drabas, Denny Lee
Book Image

Learning PySpark

By: Tomasz Drabas, Denny Lee

Overview of this book

Apache Spark is an open source framework for efficient cluster computing with a strong interface for data parallelism and fault tolerance. This book will show you how to leverage the power of Python and put it to use in the Spark ecosystem. You will start by getting a firm understanding of the Spark 2.0 architecture and how to set up a Python environment for Spark. You will get familiar with the modules available in PySpark. You will learn how to abstract data with RDDs and DataFrames and understand the streaming capabilities of PySpark. Also, you will get a thorough overview of machine learning capabilities of PySpark using ML and MLlib, graph processing using GraphFrames, and polyglot persistence using Blaze. Finally, you will learn how to deploy your applications to the cloud using the spark-submit command. By the end of this book, you will have established a firm understanding of the Spark Python API and how it can be used to build data-intensive applications.
Table of Contents (20 chapters)
Learning PySpark
Credits
Foreword
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Other features of PySpark ML in action


At the beginning of this chapter, we described most of the features of the PySpark ML library. In this section, we will provide examples of how to use some of the Transformers and Estimators.

Feature extraction

We have used quite a few models from this submodule of PySpark. In this section, we'll show you how to use the most useful ones (in our opinion).

NLP - related feature extractors

As described earlier, the NGram model takes a list of tokenized text and produces pairs (or n-grams) of words.

In this example, we will take an excerpt from PySpark's documentation and present how to clean up the text before passing it to the NGram model. Here's how our dataset looks like (abbreviated for brevity):

Tip

For the full view of how the following snippet looks like, please download the code from our GitHub repository: https://github.com/drabastomek/learningPySpark.

We copied these four paragraphs from the description of the DataFrame usage in Pipelines: http://spark...