Book Image

PySpark Cookbook

By : Denny Lee, Tomasz Drabas
Book Image

PySpark Cookbook

By: Denny Lee, Tomasz Drabas

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. The PySpark Cookbook presents effective and time-saving recipes for leveraging the power of Python and putting it to use in the Spark ecosystem. You’ll start by learning the Apache Spark architecture and how to set up a Python environment for Spark. You’ll then get familiar with the modules available in PySpark and start using them effortlessly. In addition to this, you’ll discover how to abstract data with RDDs and DataFrames, and understand the streaming capabilities of PySpark. You’ll then move on to using ML and MLlib in order to solve any problems related to the machine learning capabilities of PySpark and use GraphFrames to solve graph-processing problems. Finally, you will explore how to deploy your applications to the cloud using the spark-submit command. By the end of this book, you will be able to use the Python API for Apache Spark to solve any problems associated with building data-intensive applications.
Table of Contents (13 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Predicting forest coverage types


In this recipe, we will learn how to process data and build two classification models that aim to forecast the forest coverage type: the benchmark logistic regression model and the random forest classifier. The problem we have at hand is multinomial, that is, we have more than two classes that we want to classify our observations into.

Getting ready

To execute this recipe, you will need a working Spark environment and you would have already loaded the data into the forest DataFrame.

No other prerequisites are required.

How to do it...

Here's the code that will help us build the logistic regression model:

forest_train, forest_test = (
    forest
    .randomSplit([0.7, 0.3], seed=666)
)

vectorAssembler = feat.VectorAssembler(
    inputCols=forest.columns[0:-1]
    , outputCol='features'
)

selector = feat.ChiSqSelector(
    labelCol='CoverType'
    , numTopFeatures=10
    , outputCol='selected'
)

logReg_obj = cl.LogisticRegression(
    labelCol='CoverType'
   ...