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

Understanding the graph


To easily understand the complex relationship of city airports and the flights between each of them, we can use the concept of motifs to find patterns of airports connected by flights. The result is a DataFrame in which the column names are given by the motif keys. 

Getting ready

To make it easier to view our data within the context of Motifs, let's first create a smaller version of the graph GraphFrame called graphSmall:

edgesSubset = deptsDelays_GEO.select("tripid", "delay", "src", "dst")
graphSmall = GraphFrame(vertices, edgesSubset)

How to do it...

To execute a Motif, execute the following command:

motifs = (
    graphSmall
    .find("(a)-[ab]->(b); (b)-[bc]->(c)")
    .filter("""
        (b.id = 'SFO') 
        and (ab.delay > 500 or bc.delay > 500) 
        and bc.tripid > ab.tripid 
        and bc.tripid < ab.tripid + 10000
    """)
)
display(motifs)

The result of this query can be seen as follows:

Output of the motif query

How it works...

There is...