Book Image

Practical Data Wrangling

By : Allan Visochek
Book Image

Practical Data Wrangling

By: Allan Visochek

Overview of this book

Around 80% of time in data analysis is spent on cleaning and preparing data for analysis. This is, however, an important task, and is a prerequisite to the rest of the data analysis workflow, including visualization, analysis and reporting. Python and R are considered a popular choice of tool for data analysis, and have packages that can be best used to manipulate different kinds of data, as per your requirements. This book will show you the different data wrangling techniques, and how you can leverage the power of Python and R packages to implement them. You’ll start by understanding the data wrangling process and get a solid foundation to work with different types of data. You’ll work with different data structures and acquire and parse data from various locations. You’ll also see how to reshape the layout of data and manipulate, summarize, and join data sets. Finally, we conclude with a quick primer on accessing and processing data from databases, conducting data exploration, and storing and retrieving data quickly using databases. The book includes practical examples on each of these points using simple and real-world data sets to give you an easier understanding. By the end of the book, you’ll have a thorough understanding of all the data wrangling concepts and how to implement them in the best possible way.
Table of Contents (16 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Introducing the JSON file format


If you have worked with an Excel spreadsheet, you are already familiar with one type of data file. A spreadsheet is an example of data with a tabular format. In a tabular dataset, the entries are arranged as a series of rows and columns, where each column represents a data variable and each row represents a data entry. In Chapter 4, Reading, Exploring, and Modifying Data - Part II, you will work with CSV files, a form of tabular data.

The dataset for this chapter uses the JSON file format. JSON is an example of a hierarchical data format. Hierarchical data is more free-form than tabular data, though usually a JSON dataset will contain a series of data entries with a fixed structure.

JSON has two structures that have the same form as the Python dictionary and the Python array. The first of these structures is a collection of key value pairs, while the other is a collection of ordered values. Each of the values can be either an individual data element or an additional...