Book Image

NLTK Essentials

By : Nitin Hardeniya
Book Image

NLTK Essentials

By: Nitin Hardeniya

Overview of this book

<p>Natural Language Processing (NLP) is the field of artificial intelligence and computational linguistics that deals with the interactions between computers and human languages. With the instances of human-computer interaction increasing, it’s becoming imperative for computers to comprehend all major natural languages. Natural Language Toolkit (NLTK) is one such powerful and robust tool.</p> <p>You start with an introduction to get the gist of how to build systems around NLP. We then move on to explore data science-related tasks, following which you will learn how to create a customized tokenizer and parser from scratch. Throughout, we delve into the essential concepts of NLP while gaining practical insights into various open source tools and libraries available in Python for NLP. You will then learn how to analyze social media sites to discover trending topics and perform sentiment analysis. Finally, you will see tools which will help you deal with large scale text.</p> <p>By the end of this book, you will be confident about NLP and data science concepts and know how to apply them in your day-to-day work.</p>
Table of Contents (17 chapters)
NLTK Essentials
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Building your first NLP application


Let's start with one of the very complex NLP applications, which is summarization. The concept of summarization is quite simple. We are given an article/passage/story and you will have to generate a summary of the content automatically. Summarization actually requires deep knowledge of NLP because we need to understand not just the structure of the sentence but also the structure of the entire text. We also need to know about genre of the text and the theme of the content.

Since it all looks very complex to us, let's try a very intuitive approach. We will assume that summarization is nothing but ranking of the sentences based on their importance and significance to you. We will create a few rules based on the understanding and the preprocessing tools we have learned so far and will try to come up with an acceptable summary of the news article.

I have scraped an article from the New York Times in a text file nyt.txt, in the following example. The idea here...