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)

Advanced List Comprehension and the zip Function

In this section, we will deep dive into the heart of list comprehension. We have already seen a basic form of it, including something as simple as a = [i for i in range(0, 30)] to something a bit more complex that involves one conditional statement. However, as we already mentioned, list comprehension is a very powerful tool and, in this section, we will explore this amazing tool further. We will investigate another close relative of list comprehension called generators, which also provides a way to create lists, and work with zip and its related functions and methods. By the end of this section, you will be confident in handling complicated logical problems.

Introduction to Generator Expressions

In the previous chapter, while discussing advanced data structures, we witnessed functions such as repeat. We said that they represent a special type of function known as iterators. We also showed you how the lazy evaluation of an iterator...