Some English words occur together more frequently. For example – Sky High, do or die, best performance, heavy rain etc. So, in a text document we may need to identify such pair of words which will help in sentiment analysis. First, we need to generate such word pairs from the existing sentence maintain their current sequences. Such pairs are called bigrams. Python has a bigram function as part of NLTK library which helps us generate these pairs.

Example

import nltk

word_data = "The best performance can bring in sky high success."
nltk_tokens = nltk.word_tokenize(word_data)  	

print(list(nltk.bigrams(nltk_tokens)))

When we run the above program we get the following output −

[(''The'', ''best''), (''best'', ''performance''), (''performance'', ''can''), (''can'', ''bring''), 
(''bring'', ''in''), (''in'', ''sky''), (''sky'', ''high''), (''high'', ''success''), (''success'', ''.'')]

This result can be used in statistical findings on the frequency of such pairs in a given text. That will corelate to the general sentiment of the descriptions
present int he body of the text.