Book Image

Hands-On Machine Learning with scikit-learn and Scientific Python Toolkits

By : Tarek Amr
Book Image

Hands-On Machine Learning with scikit-learn and Scientific Python Toolkits

By: Tarek Amr

Overview of this book

Machine learning is applied everywhere, from business to research and academia, while scikit-learn is a versatile library that is popular among machine learning practitioners. This book serves as a practical guide for anyone looking to provide hands-on machine learning solutions with scikit-learn and Python toolkits. The book begins with an explanation of machine learning concepts and fundamentals, and strikes a balance between theoretical concepts and their applications. Each chapter covers a different set of algorithms, and shows you how to use them to solve real-life problems. You’ll also learn about various key supervised and unsupervised machine learning algorithms using practical examples. Whether it is an instance-based learning algorithm, Bayesian estimation, a deep neural network, a tree-based ensemble, or a recommendation system, you’ll gain a thorough understanding of its theory and learn when to apply it. As you advance, you’ll learn how to deal with unlabeled data and when to use different clustering and anomaly detection algorithms. By the end of this machine learning book, you’ll have learned how to take a data-driven approach to provide end-to-end machine learning solutions. You’ll also have discovered how to formulate the problem at hand, prepare required data, and evaluate and deploy models in production.
Table of Contents (18 chapters)
1
Section 1: Supervised Learning
8
Section 2: Advanced Supervised Learning
13
Section 3: Unsupervised Learning and More

Splitting sentences into tokens

"A word after a word after a word is power."
– Margaret Atwood

So far, the data we have dealt with has either been table data with columns as features or image data with pixels as features. In the case of text, things are less obvious. Shall we use sentences, words, or characters as our features? Sentences are very specific. For example, it is very unlikely to have the exact same sentence appearing in two or more Wikipedia articles. Therefore, if we use sentences as features, we will end up with tons of features that do not generalize well.

Characters, on the other hand, are limited. For example, there are only 26 letters in the English language. This small variety is likely to limit the ability of the separate characters to carry enough information for the downstream algorithms to extract. As a result, words are typically used as features for most tasks.

Later in this chapter, we will see that fairly...