Book Image

Essential PySpark for Scalable Data Analytics

By : Sreeram Nudurupati
Book Image

Essential PySpark for Scalable Data Analytics

By: Sreeram Nudurupati

Overview of this book

Apache Spark is a unified data analytics engine designed to process huge volumes of data quickly and efficiently. PySpark is Apache Spark's Python language API, which offers Python developers an easy-to-use scalable data analytics framework. Essential PySpark for Scalable Data Analytics starts by exploring the distributed computing paradigm and provides a high-level overview of Apache Spark. You'll begin your analytics journey with the data engineering process, learning how to perform data ingestion, cleansing, and integration at scale. This book helps you build real-time analytics pipelines that help you gain insights faster. You'll then discover methods for building cloud-based data lakes, and explore Delta Lake, which brings reliability to data lakes. The book also covers Data Lakehouse, an emerging paradigm, which combines the structure and performance of a data warehouse with the scalability of cloud-based data lakes. Later, you'll perform scalable data science and machine learning tasks using PySpark, such as data preparation, feature engineering, and model training and productionization. Finally, you'll learn ways to scale out standard Python ML libraries along with a new pandas API on top of PySpark called Koalas. By the end of this PySpark book, you'll be able to harness the power of PySpark to solve business problems.
Table of Contents (19 chapters)
1
Section 1: Data Engineering
6
Section 2: Data Science
13
Section 3: Data Analysis

Feature transformation

Feature transformation is the process of carefully reviewing the various variable types, such as categorical variables and continuous variables, present in the training data and determining the best type of transformation to achieve optimal model performance. This section will describe, with code examples, how to transform a few common types of variables found in machine learning datasets, such as text and numerical variables.

Transforming categorical variables

Categorical variables are pieces of data that have discrete values with a limited and finite range. They are usually text-based in nature, but they can also be numerical. Examples include country codes and the month of the year. We mentioned a few techniques regarding how to extract features from text variables in the previous section. In this section, we will explore a few other algorithms to transform categorical variables.

The tokenization of text into individual terms

The Tokenizer class...