160. 여러 이터러블을 쓰는 리스트 컴프리헨션

1xs = [1, 2, 3]
2ys = [10, 20]
3pairs = [x * y for x in xs for y in ys if x != 2]
4zipped = [a - b for a, b in zip(xs, ys)]
5grid = [[r + c for c in range(r)] for r in range(1, 4)]
6flat = [v for row in grid for v in row]
7print(len(pairs), sum(pairs))
8print(zipped, len(zipped))
9print(len(flat), sum(flat), flat[-2:])