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Python Feature Engineering Cookbook

You're reading from   Python Feature Engineering Cookbook A complete guide to crafting powerful features for your machine learning models

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Product type Paperback
Published in Aug 2024
Publisher Packt
ISBN-13 9781835883587
Length 396 pages
Edition 3rd Edition
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Author (1):
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Soledad Galli Soledad Galli
Author Profile Icon Soledad Galli
Soledad Galli
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Toc

Table of Contents (14) Chapters Close

Preface 1. Chapter 1: Imputing Missing Data FREE CHAPTER 2. Chapter 2: Encoding Categorical Variables 3. Chapter 3: Transforming Numerical Variables 4. Chapter 4: Performing Variable Discretization 5. Chapter 5: Working with Outliers 6. Chapter 6: Extracting Features from Date and Time Variables 7. Chapter 7: Performing Feature Scaling 8. Chapter 8: Creating New Features 9. Chapter 9: Extracting Features from Relational Data with Featuretools 10. Chapter 10: Creating Features from a Time Series with tsfresh 11. Chapter 11: Extracting Features from Text Variables 12. Index 13. Other Books You May Enjoy

Extracting features from dates with pandas

The values of datetime variables can be dates, time, or both. We’ll begin by focusing on those variables that contain dates. We rarely use raw dates with machine learning algorithms. Instead, we extract simpler features, such as the year, month, or day of the week, that allow us to capture insights such as seasonality, periodicity, and trends.

The pandas Python library is great for working with date and time. Utilizing the pandas dt module, we can access the datetime properties of a pandas Series to extract many features. However, to leverage this functionality, the variables need to be cast into a data type that supports these operations, such as datetime or timedelta.

Note

The datetime variables can be cast as objects, particularly when we load the data from a CSV file. To extract the date and time features that we will discuss throughout this chapter, it is necessary to recast the variables as datetime.

In this recipe...

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