Explore Python, machine learning, and the NLTK library

This article is for software developers--particularly those coming from a Ruby or Java language background--who are facing their first machine learning implementation. I was recently given the assignment to create an RSS feed categorization subsystem for a client. The goal was to read dozens or even hundreds of RSS feeds and automatically categorize their many articles into one of dozens of predefined subject areas. The content, navigation, and search functionality of the client website would be driven by the results of this daily automated feed retrieval and categorization. The client suggested using machine learning, perhaps with Apache Mahout and Hadoop, as she had recently read articles about those technologies. Her development team and ours, however, are fluent in Ruby rather than Java technology. This article describes the technical journey, learning process, and ultimate implementation of a solution. My first question was, "what exactly is machine learning?"