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

Understanding XML


XML, like JSON, is a hierarchical data format that allows a nested data structure. If you have worked with HTML before, you might be familiar with the general structure and syntax of XML, which HTML is based on.

An XML dataset consists of a nested tree of elements where each element may contain text with a particular value, another element or a collection of additional elements. Each element in the tree may also contain any number of attributes which describe the element.

Each element is represented by an opening tag and a closing tag. An opening tag indicates the beginning of an XML element. It is written by writing the name of the tag inside angle brackets. The following is what an XML opening tag looks like:

<tagname>

A closing tag follows the opening tag and indicates the end of an element. It is written by specifying the name of a tag inside angle brackets with a / before the name. The following is what an XML closing tag looks like:

</tagname>

Note

In other parts...