getAllSentences.py

import itertools

def getAllSentences(input_data):
	""" 
	 take cartesian cross product of list and join to form the sentences to get all sentences.
	 Assumption: The order for sentences is that for every element in ith list create all sentences from i-1..0th list
	 i.e. if list = [[1,2],[3,4],[5]]
	 order of sentences = [135,145,235,245]
	""" 
	return [" ".join(sentence) for sentence in list(itertools.product(*input_data))]


#for testing the function
input_data = [ ['Birds', 'Animals', 'Humans'],
          ['are'] ,
          ['angry' , 'happy']]
for sentence in getAllSentences(input_data):
	print sentence