installing and using nltk how to install nltk on your operating system is described in detail at packages nltk and pyyaml to check whether your installation was successfulopen python interpreter and type the followingimport nltk you will find very nice tutorial for nltk in the book python text processing with nltk cookbook to play little bit with stemmeryou can visit the accompanied web page nltk comes with different stemmers this is necessarybecause every language has different set of rules for stemming for englishwe can take snowballstemmer import nltk stem snltk stem snowballstemmer('english' stem("graphics" 'graphics stem("imaging" 'imags stem("image" 'imags stem("imagination") 'imagins stem("imagine" 'imaginnote that stemming does not necessarily have to result into valid english words it also works with verbs as followss stem("buys" 'buys stem("buying" 'buys stem("bought" 'bought