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)

Performing rule-based text classification using keywords

In this recipe, we will use the keywords to classify the business and sport data. We will create a classifier with keywords that we will choose by ourselves from the frequency distributions from the previous recipe.

Getting ready

We will continue using classes from the sklearn, numpy, and nltk packages that we used in the previous recipe.

How to do it…

In this recipe, we will use hand-picked business and sport vocabulary to create a keyword classifier that we will evaluate using the same method as the dummy classifier in the previous recipe. The steps for this recipe are as follows:

  1. Do the necessary imports:
    import numpy as np
    import string
    from sklearn import preprocessing
    from sklearn.metrics import classification_report
    from sklearn.model_selection import train_test_split
    from sklearn.feature_extraction.text import CountVectorizer
    from itertools import repeat
    from nltk.probability import FreqDist...