def positivity_reducer(self, word, ratings):
        avg, total = avg_and_total(ratings)

        if total < MINIMUM_OCCURENCES:
            return

        yield (int(avg * 100), total), word
Emit average star rating, word in a format we can easily
dataset/ETHPy150Open Yelp/dataset-examples/positive_category_words/simple_global_positivity.py/PositiveWords.positivity_reducer