In this section, we will look at building an application to do sentiment analysis on text using the NLTK tools. There are several different options for how to direct NLTK to do sentiment analysis on text, so our experiments with these various methods will teach us a bit about what is going on inside NLTK and also about how sentiment analysis works.
You might recall that we installed and tested NLTK in Chapter 1, Expanding Your Data Mining Toolbox, and we used NLTK for entity matching back in Chapter 3, Entity Matching, so if you skipped those chapters, you may need to install or upgrade NLTK now. To do this from within Anaconda, open the Tools menu, select Open a terminal, and type:
conda upgrade nltk
This will fetch ...