Training scikit-learn classifiers

Scikit-learn is one of the best machine learning libraries available in any programming language. It contains all sorts of machine learning algorithms for many different purposes, but they all follow the same fit/predict design pattern:

• Fit the model to the data

• Use the model to make predictions

We won't be accessing the scikit-learn models directly in this recipe. Instead, we'll be using NLTK's SklearnClassifier class, which is a wrapper class around a scikit-learn model to make it conform to NLTK's ClassifierI interface. This means that the SklearnClassifier class can be trained and used much like the classifiers we've used in the previous recipes in this chapter.

Note

I may use the terms scikit-learn and sklearn interchangeably in this recipe.

Getting ready

To use the SklearnClassifier class, you must have scikit-learn installed. Instructions are available online at http://scikit-learn.org/stable/install.html. If you have all the dependencies installed, such...