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)

Getting started with semantic search

In this recipe, we will get a glimpse of how to get started on expanding search with the help of a word2vec model. When we search for a term, we expect the search engine to show us a result with a synonym when we didn't use the exact term contained in the document. Search engines are far more complicated than what we'll show in the recipe, but this should give you a taste of what it's like to build a customizable search engine.

Getting ready

We will be using an IMDb dataset from Kaggle, which can be downloaded from https://www.kaggle.com/PromptCloudHQ/imdb-data. Download the dataset and unzip the CSV file.

We will also use a small-scale Python search engine called Whoosh. Install it using pip:

pip install whoosh

We will also be using the pretrained word2vec model from the Using word embeddings recipe.

How to do it…

We will create a class for the Whoosh search engine that will create a document index based...