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 databases


In addition to using plenty of memory, large amounts of data can also take a long time to process. In some cases, it may make sense to process a large dataset from one input file to another output file. Data wrangling, however, is often an iterative process, involving back and forth between data analysis and modification. It can be hard to iterate with a large dataset using a Python script. This is where database management systems can be helpful. 

A database simply refers to an organized collection of data. In contrast to files, databases are typically organized structurally to index each of the documents (another word for data entry) making it faster to retrieve specific documents or groups of documents. A database management system is software for interfacing with a database to do the following:

  • Retrieve data from a database
  • Modify data in a database
  • Write data to a database

Database management systems define a language for analyzing and modifying data that does not...