I've got the following code. sum_review = reduce(add,[book['rw'] for book in books]) sum_rating = reduce(add,[book['rg'] for book in books]) items = len(books) avg_review = sum_review/items avg_rating = sum_rating/items What I'd like is this. sum_review,sum_rating = reduce(add,([book['rw'],[book['rg']) for book in books]) items = len(books) avg_review = sum_review/items avg_rating = sum_rating/items Obviously this doesn't work. How can I solve this redundancy, without a regular loop?