Machine learning is one of the current hot topics in the IT world. The huge growth of data and the increase of computing power may be the best supporting factors which lead to the current condition. Besides the good trend, machine learning is very interesting for me personally. So, I try to find some information about it and that leads me to Python and its NLTK (Natural Language Toolkit) library. The last time I use Python is about two years ago when I learn about Django, the web development framework for Python.