NLTK(Natural Language Toolkit)
Natural Language Processing with Python provides a practical introduction to programming for language processing.
For platform-specific instructions, read here
pip install nltk
After NLTK has been downloaded, install required packages
import nltk
from nltk.stem import WordNetLemmatizer
nltk.download('popular', quiet=True) # for downloading popular packages
nltk.download('punkt')
nltk.download('wordnet')