Book Image

Natural Language Processing and Computational Linguistics

By : Bhargav Srinivasa-Desikan
Book Image

Natural Language Processing and Computational Linguistics

By: Bhargav Srinivasa-Desikan

Overview of this book

Modern text analysis is now very accessible using Python and open source tools, so discover how you can now perform modern text analysis in this era of textual data. This book shows you how to use natural language processing, and computational linguistics algorithms, to make inferences and gain insights about data you have. These algorithms are based on statistical machine learning and artificial intelligence techniques. The tools to work with these algorithms are available to you right now - with Python, and tools like Gensim and spaCy. You'll start by learning about data cleaning, and then how to perform computational linguistics from first concepts. You're then ready to explore the more sophisticated areas of statistical NLP and deep learning using Python, with realistic language and text samples. You'll learn to tag, parse, and model text using the best tools. You'll gain hands-on knowledge of the best frameworks to use, and you'll know when to choose a tool like Gensim for topic models, and when to work with Keras for deep learning. This book balances theory and practical hands-on examples, so you can learn about and conduct your own natural language processing projects and computational linguistics. You'll discover the rich ecosystem of Python tools you have available to conduct NLP - and enter the interesting world of modern text analysis.
Table of Contents (22 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Why Python?


In Python, we represent text in the form of string [1], which are objects of the str [2] class. They are an immutable sequence of Unicode code points or characters. It is important to make a careful distinction here, though; in Python 3, all strings are by default Unicode, but in Python 2, the str class is limited to ASCII code, and there is a Unicode class to deal with Unicodes.

Unicode is merely an encoding language or a way we handle text. For example, the Unicode value for the letter Z is U+005A. There are many encoding types, and historically in Python, developers were expected to deal with different encodings on their own, with all the low-level action happening in bytes. In fact, the shift in the way Python handles Unicode has led to a lot of discussions [3], criticism [4], and praise [5] within the community. It also remains an important point of contention when we are porting code from Python 2 and Python 3.

We said earlier on that the low-level action was going on in...