Book Image

Python Natural Language Processing Cookbook

By : Zhenya Antić
Book Image

Python Natural Language Processing Cookbook

By: Zhenya Antić

Overview of this book

Python is the most widely used language for natural language processing (NLP) thanks to its extensive tools and libraries for analyzing text and extracting computer-usable data. This book will take you through a range of techniques for text processing, from basics such as parsing the parts of speech to complex topics such as topic modeling, text classification, and visualization. Starting with an overview of NLP, the book presents recipes for dividing text into sentences, stemming and lemmatization, removing stopwords, and parts of speech tagging to help you to prepare your data. You’ll then learn ways of extracting and representing grammatical information, such as dependency parsing and anaphora resolution, discover different ways of representing the semantics using bag-of-words, TF-IDF, word embeddings, and BERT, and develop skills for text classification using keywords, SVMs, LSTMs, and other techniques. As you advance, you’ll also see how to extract information from text, implement unsupervised and supervised techniques for topic modeling, and perform topic modeling of short texts, such as tweets. Additionally, the book shows you how to develop chatbots using NLTK and Rasa and visualize text data. By the end of this NLP book, you’ll have developed the skills to use a powerful set of tools for text processing.
Table of Contents (10 chapters)

Chapter 3: Representing Text – Capturing Semantics

Representing the meaning of words, phrases, and sentences in a form that's understandable to computers is one of the pillars of NLP processing. Machine learning, for example, represents each data point as a fixed-size vector, and we are faced with the question of how to turn words and sentences into vectors. Almost any NLP task starts with representing the text in some numeric form, and this chapter will show several ways of doing that. Once you've learned how to represent text as vectors, you will be able to perform tasks such as classification, which will be described in later chapters.

We will also learn how to turn phrases such as fried chicken into vectors, how to train a word2vec model, and how to create a small search engine with semantic search.

The following recipes will be covered in this chapter:

  • Putting documents into a bag of words
  • Constructing the N-gram model
  • Representing texts...