您可以使用defaultdict：
>>> from collections import defaultdict>>> d = defaultdict(list)>>> a = ['1', '2']>>> for i in a:... for j in range(int(i), int(i) + 2):... d[j].append(i)...>>> ddefaultdict(<type 'list'>, {1: ['1'], 2: ['1', '2'], 3: ['2']})>>> d.items()[(1, ['1']), (2, ['1', '2']), (3, ['2'])]
