NLTK is a powerful Python library for computational linguistics and text classification. NLTK include about 50 corpora and lexical resources such as Wordnet. NLTK is the most used tool for natural language processing in Python. It includes powerful algorithms for text tokenization, parsing, semantic reasoning, and text classification. We can find a complete guide of NLTK from http://nltk.org/.
We may need to install PyYaml in order to use NLTK. We can download PyYaml from http://pyyaml.org/wiki/PyYAML.
Maximum entropy (or Logistic regression)
In this chapter, we will use NLTK 3.0, which supports Python 3. However, it's still in alpha release (Sept 2013) and is likely to contain bugs. We can download the NLTK 3 from http...