pp

spam = ['apples', 'bananas', 'tofu', 'cats']

def pretty_join(words):
    if len(words) == 1:
        return words[0]
    else:
        comma_separated = ", ".join(words[:-1])
        last_word = words[-1]
        return "{0}, and {1}".format(comma_separated, last_word)


print(pretty_join(spam))

input("enter to quit")