Book Image

Building Machine Learning Systems with Python

Book Image

Building Machine Learning Systems with Python

Overview of this book

Machine learning, the field of building systems that learn from data, is exploding on the Web and elsewhere. Python is a wonderful language in which to develop machine learning applications. As a dynamic language, it allows for fast exploration and experimentation and an increasing number of machine learning libraries are developed for Python.Building Machine Learning system with Python shows you exactly how to find patterns through raw data. The book starts by brushing up on your Python ML knowledge and introducing libraries, and then moves on to more serious projects on datasets, Modelling, Recommendations, improving recommendations through examples and sailing through sound and image processing in detail. Using open-source tools and libraries, readers will learn how to apply methods to text, images, and sounds. You will also learn how to evaluate, compare, and choose machine learning techniques. Written for Python programmers, Building Machine Learning Systems with Python teaches you how to use open-source libraries to solve real problems with machine learning. The book is based on real-world examples that the user can build on. Readers will learn how to write programs that classify the quality of StackOverflow answers or whether a music file is Jazz or Metal. They will learn regression, which is demonstrated on how to recommend movies to users. Advanced topics such as topic modeling (finding a text's most important topics), basket analysis, and cloud computing are covered as well as many other interesting aspects.Building Machine Learning Systems with Python will give you the tools and understanding required to build your own systems, which are tailored to solve your problems.
Table of Contents (20 chapters)
Building Machine Learning Systems with Python
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Fetching the Twitter data


Naturally, we need tweets and their corresponding labels that tell us whether a tweet contains positive, negative, or neutral sentiment. In this chapter, we will use the corpus from Niek Sanders, who has done an awesome job of manually labeling more than 5000 tweets and granted us permission to use it in this chapter.

To comply with Twitter's terms of services, we will not provide any data from Twitter nor show any real tweets in this chapter. Instead, we can use Sanders' hand-labeled data, which contains the tweet IDs and their hand-labeled sentiment, and use his script, install.py, to fetch the corresponding Twitter data. As the script is playing nicely with Twitter's servers, it will take quite some time to download all the data for more than 5000 tweets. So it is a good idea to start it now.

The data comes with four sentiment labels:

>>> X, Y = load_sanders_data()
>>> classes = np.unique(Y)
>>> for c in classes:
        print("#%s: %i...