Book Image

Data Wrangling with Python

By : Dr. Tirthajyoti Sarkar, Shubhadeep Roychowdhury
Book Image

Data Wrangling with Python

By: Dr. Tirthajyoti Sarkar, Shubhadeep Roychowdhury

Overview of this book

For data to be useful and meaningful, it must be curated and refined. Data Wrangling with Python teaches you the core ideas behind these processes and equips you with knowledge of the most popular tools and techniques in the domain. The book starts with the absolute basics of Python, focusing mainly on data structures. It then delves into the fundamental tools of data wrangling like NumPy and Pandas libraries. You'll explore useful insights into why you should stay away from traditional ways of data cleaning, as done in other languages, and take advantage of the specialized pre-built routines in Python. This combination of Python tips and tricks will also demonstrate how to use the same Python backend and extract/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, you'll cover how to handle missing or wrong data, and reformat it based on the requirements from the downstream analytics tool. The book will further help you grasp concepts through real-world examples and datasets. By the end of this book, you will be confident in using a diverse array of sources to extract, clean, transform, and format your data efficiently.
Table of Contents (12 chapters)
Data Wrangling with Python
Preface
Appendix

Introduction to Beautiful Soup 4 and Web Page Parsing


The ability to read and understand web pages is one of paramount interest for 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 for the movies is best obtained by the websites such as IMDB and that data does not come pre-packaged in nice forms(CSV, JSON< and so on), so you need to know how to download and read web page.

Furthermore, 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 of 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...