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

Summary


In this chapter, we dived deep into the pandas library to learn advanced data wrangling techniques. We started with some advanced subsetting and filtering on DataFrames and round this up by learning about boolean indexing and conditional selection of a subset of data. We also covered how to set and reset the index of a DataFrame, especially while initializing.

Next, we learned about a particular topic that has a deep connection with traditional relational database systems – the group by method. Then, we dived deep into an important skill for data wrangling - checking for and handling missing data. We showed you how pandas help in handling missing data using various imputation techniques. We also discussed methods for dropping missing values. Furthermore, methods and usage examples of concatenation and merging of DataFrame objects were shown. We saw the join method and how it compares to a similar operation in SQL.

Lastly, miscellaneous useful methods on DataFrames, such as randomized...