Book Image

The Data Wrangling Workshop - Second Edition

By : Brian Lipp, Shubhadeep Roychowdhury, Dr. Tirthajyoti Sarkar
Book Image

The Data Wrangling Workshop - Second Edition

By: Brian Lipp, Shubhadeep Roychowdhury, Dr. Tirthajyoti Sarkar

Overview of this book

While a huge amount of data is readily available to us, it is not useful in its raw form. For data to be meaningful, it must be curated and refined. If you’re a beginner, then The Data Wrangling Workshop will help to break down the process for you. You’ll start with the basics and build your knowledge, progressing from the core aspects behind data wrangling, to using the most popular tools and techniques. This book starts by showing you how to work with data structures using Python. Through examples and activities, you’ll understand why you should stay away from traditional methods of data cleaning used in other languages and take advantage of the specialized pre-built routines in Python. Later, you’ll learn how to use the same Python backend to extract and transform data from an array of sources, including the internet, large database vaults, and Excel financial tables. To help you prepare for more challenging scenarios, the book teaches you how to handle missing or incorrect data, and reformat it based on the requirements from your downstream analytics tool. By the end of this book, you will have developed a solid understanding of how to perform data wrangling with Python, and learned several techniques and best practices to extract, clean, transform, and format your data efficiently, from a diverse array of sources.
Table of Contents (11 chapters)
Preface

Introduction to Beautiful Soup 4 and Web Page Parsing

The ability to read and understand web pages is of paramount interest to a person collecting and formatting data. For example, consider the task of gathering data about movies and then formatting it for a downstream system. Data from movie databases is best obtained from websites such as IMDb, and that data does not come pre-packaged in nice forms (such as CSV or JSON), so you need to know how to download and read a web page.

You also need to be equipped with the knowledge of the structure of a web page so that you can design a system that can search for (query) a particular piece of information from a whole web page and get the value from it. This involves understanding the grammar of markup languages and being able to write something that can parse them. Doing this, and keeping all the edge cases in mind, for something like HTML is already incredibly complex, and if you extend the scope of the bespoke markup language to include...