Natural Language Processing: Python and NLTK

Understanding lemmatization

Lemmatization is the process in which we transform the word into a form with a different word category. The word formed after lemmatization is entirely different. The built-in morphy() function is used for lemmatization in WordNetLemmatizer. The inputted word is left unchanged if it is not found in WordNet. In the argument, pos refers to the part of speech category of the inputted word.

Consider an example of lemmatization in NLTK:

>>> import nltk
>>> from nltk.stem import WordNetLemmatizer
>>> lemmatizer_output=WordNetLemmatizer()
>>> lemmatizer_output.lemmatize('working')
'working'
>>> lemmatizer_output.lemmatize('working',pos='v')
'work'
>>> lemmatizer_output.lemmatize('works')
'work'

The WordNetLemmatizer library may ...