Book Image

Pandas 1.x Cookbook - Second Edition

By : Matt Harrison, Theodore Petrou
Book Image

Pandas 1.x Cookbook - Second Edition

By: Matt Harrison, Theodore Petrou

Overview of this book

The pandas library is massive, and it's common for frequent users to be unaware of many of its more impressive features. The official pandas documentation, while thorough, does not contain many useful examples of how to piece together multiple commands as one would do during an actual analysis. This book guides you, as if you were looking over the shoulder of an expert, through situations that you are highly likely to encounter. This new updated and revised edition provides you with unique, idiomatic, and fun recipes for both fundamental and advanced data manipulation tasks with pandas. Some recipes focus on achieving a deeper understanding of basic principles, or comparing and contrasting two similar operations. Other recipes will dive deep into a particular dataset, uncovering new and unexpected insights along the way. Many advanced recipes combine several different features across the pandas library to generate results.
Table of Contents (17 chapters)
15
Other Books You May Enjoy
16
Index

Chaining Series methods

In Python, every variable points to an object, and many attributes and methods return new objects. This allows sequential invocation of methods using attribute access. This is called method chaining or flow programming. pandas is a library that lends itself well to method chaining, as many Series and DataFrame methods return more Series and DataFrames, upon which more methods can be called.

To motivate method chaining, let's take an English sentence and translate the chain of events into a chain of methods. Consider the sentence: A person drives to the store to buy food, then drives home and prepares, cooks, serves, and eats the food before cleaning the dishes.

A Python version of this sentence might take the following form:

(person.drive('store')
       .buy('food')
       .drive('home')
       .prepare('food')
       .cook('food')
       .serve('food')
       .eat('food...