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)

K-means topic modeling with BERT

In this recipe, we will use the K-means algorithm to execute unsupervised topic classification, using the BERT embeddings to encode the data. This recipe shares lots of commonalities with the Clustering sentences using K-means: unsupervised text classification recipe from Chapter 4, Classifying Texts.

Getting ready

We will be using the sklearn.cluster.KMeans object to do the unsupervised clustering, along with Hugging Face sentence transformers. To install sentence transformers, use the following commands:

conda create -n newenv python=3.6.10 anaconda
conda install pytorch torchvision cudatoolkit=10.2 -c pytorch
pip install transformers
pip install -U sentence-transformers

How to do it…

The steps for this recipe are as follows:

  1. Perform the necessary imports:
    import re
    import string
    import pandas as pd
    from sklearn.cluster import KMeans
    from nltk.probability import FreqDist
    from Chapter01.tokenization import tokenize_nltk...