Book Image

Pandas Cookbook

By : Theodore Petrou
Book Image

Pandas Cookbook

By: Theodore Petrou

Overview of this book

This book will provide you with unique, idiomatic, and fun recipes for both fundamental and advanced data manipulation tasks with pandas 0.20. 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. 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 like one would do during an actual analysis. This book guides you, as if you were looking over the shoulder of an expert, through practical situations that you are highly likely to encounter. Many advanced recipes combine several different features across the pandas 0.20 library to generate results.
Table of Contents (12 chapters)

Inverting stacked data

DataFrames have two similar methods, stack and melt, to convert horizontal column names into vertical column values. DataFrames have the ability to invert these two operations directly with the unstack and pivot methods respectively. stack/unstack are simpler methods that allow control over only the column/row indexes, while melt/pivot gives more flexibility to choose which columns are reshaped.

Getting ready

In this recipe, we will stack/melt a dataset and promptly invert the operation with unstack/pivot back to its original form.

How to do it...

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