def review_category_mapper(self, _, data):
        if data['type'] == 'review':
            yield data['business_id'], ('review', data['text'])
        elif data['type'] == 'business':
            yield data['business_id'], ('categories', data['categories'])
Visit reviews and businesses, yielding out (business_id,
dataset/ETHPy150Open Yelp/dataset-examples/category_predictor/category_predictor.py/CategoryPredictor.review_category_mapper