Book Image

Python Data Analysis - Second Edition

By : Ivan Idris
Book Image

Python Data Analysis - Second Edition

By: Ivan Idris

Overview of this book

Data analysis techniques generate useful insights from small and large volumes of data. Python, with its strong set of libraries, has become a popular platform to conduct various data analysis and predictive modeling tasks. With this book, you will learn how to process and manipulate data with Python for complex analysis and modeling. We learn data manipulations such as aggregating, concatenating, appending, cleaning, and handling missing values, with NumPy and Pandas. The book covers how to store and retrieve data from various data sources such as SQL and NoSQL, CSV fies, and HDF5. We learn how to visualize data using visualization libraries, along with advanced topics such as signal processing, time series, textual data analysis, machine learning, and social media analysis. The book covers a plethora of Python modules, such as matplotlib, statsmodels, scikit-learn, and NLTK. It also covers using Python with external environments such as R, Fortran, C/C++, and Boost libraries.
Table of Contents (22 chapters)
Python Data Analysis - Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface
Key Concepts
Online Resources

Filtering out stopwords, names, and numbers


Stopwords are common words that have very low information value in a text. It is a common practice in text analysis to get rid of stopwords. NLTK has a stopwords corpora for a number of languages. Load the English stopwords corpus and print some of the words:

sw = set(nltk.corpus.stopwords.words('english')) 
print("Stop words:", list(sw)[:7]) 

The following common words are printed:

Stop words: ['between', 'who', 'such', 'ourselves', 'an', 'ain', 'ours'] 

Note that all the words in this corpus are in lowercase.

NLTK also has a Gutenberg corpus. The Gutenberg project is a digital library of books, mostly with expired copyright, which are available for free on the Internet (see http://www.gutenberg.org/).

Load the Gutenberg corpus and print some of its filenames:

gb = nltk.corpus.gutenberg 
print("Gutenberg files:\n", gb.fileids()[-5:]) 

Some of the titles printed may be familiar to you:

Gutenberg files:  ['milton-paradise.txt...