Book Image

Python Feature Engineering Cookbook

By : Soledad Galli
Book Image

Python Feature Engineering Cookbook

By: Soledad Galli

Overview of this book

Feature engineering is invaluable for developing and enriching your machine learning models. In this cookbook, you will work with the best tools to streamline your feature engineering pipelines and techniques and simplify and improve the quality of your code. Using Python libraries such as pandas, scikit-learn, Featuretools, and Feature-engine, you’ll learn how to work with both continuous and discrete datasets and be able to transform features from unstructured datasets. You will develop the skills necessary to select the best features as well as the most suitable extraction techniques. This book will cover Python recipes that will help you automate feature engineering to simplify complex processes. You’ll also get to grips with different feature engineering strategies, such as the box-cox transform, power transform, and log transform across machine learning, reinforcement learning, and natural language processing (NLP) domains. By the end of this book, you’ll have discovered tips and practical solutions to all of your feature engineering problems.
Table of Contents (13 chapters)

Performing Yeo-Johnson transformation on numerical variables

The Yeo-Johnson transformation is an extension of the Box-Cox transformation and can be used on variables with zero and negative values, as well as positive values. These transformations can be defined as follows:

  • ; if λ is not 0 and X >= zero
  • ln(X + 1 ); if λ is zero and X >= zero
  • ; if λ is not 2 and X is negative
  • -ln(-X + 1); if λ is 2 and X is negative

In this recipe, we will perform the Yeo-Johnson transformation using SciPy, scikit-learn, and Feature-engine.

How to do it...

Let's begin by importing the necessary libraries and getting the dataset ready:

  1. Import the required Python libraries...