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 5: Getting Started with Information Extraction

In this chapter, we will cover the basics of information extraction. We will start with extracting emails and URLs from job announcements. Then we will use an algorithm called the Levenshtein distance to find similar strings. Next, we will use spaCy to find named entities in text, and later we will train our own named entity recognition (NER) model in spaCy. We will then do basic sentiment analysis, and finally, we will train two custom sentiment analysis models.

You will learn how to use existing tools and train your own models for information extraction tasks.

We will cover the following recipes in this chapter:

  • Using regular expressions
  • Finding similar strings: the Levenshtein distance
  • Performing NER using spaCy
  • Training your own NER model with spaCy
  • Discovering sentiment analysis
  • Sentiment for short texts using LSTM: Twitter
  • Using BERT for sentiment analysis