the natural language tool kit perhaps the most important library of python to work with text data is nltk or the natural language tool kit this section introduce nltk and its important modules we go over the installation procedure of the library and brief description of its important modules installation and introduction the nltk package can be installed in the same way as most of the other packages used in this bookwhich is by using the pip or conda command conda install nltk we can verify the installation by importing the package in an ipython/python shell in [ ]import nltk there' an important difference for the nltk library as compared to other standard libraries in case of other librariesin generalwe don' need to download any auxiliary data but for the nltk library to work to its full potentialwe would require some auxiliary datawhich are mostly various corpora this data is leveraged by multiple functions and modules in the library we can download this data by executing the following command in the python shell in [ ]nltk download(this command will give us the screen shown in figure - where we can select the additional data we want to install and select the installation location we will select to install all the additional data and packages available figure - nltk download option