Modify the sentence-generator program of Case Study so that it inputs its vocabulary from a set of text files at startup. The filenames are nouns.txt, verbs. txt, articles.txt, and prepositions.txt.

(HINT: Define a single new function, getWords. This function should expect a filename as an argument. The function should open an input file with this name, define a temporary list, read words from the file, and add them to the list. The function should then convert the list to a tuple and return this tuple. Call the function with an actual filename to initialize each of the four variables for the vocabulary.)

Case Study: Generating Sentences code:

import random
articles = ("A", "THE")
nouns = ("BOY", "GIRL", "BAT", "BALL")
verbs = ("HIT", "SAW", "LIKED")
prepositions = ("WITH", "BY")

def sentence():
return nounPhrase() + " " + verbPhrase()
def nounPhrase():
return random.choice(articles) + " " + random.choice(nouns)
def verbPhrase():
return random.choice(verbs) + " " + nounPhrase() + " " + \
prepositionalPhrase()
def prepositionalPhrase():
return random.choice(prepositions) + " " + nounPhrase()
def main():
number = int(input("Enter the number of sentences: "))
for count in range(number):
print(sentence())
if __name__ == "__main__":
main()