如下所示：
>>> dict={}
>>> dict['list']=[]
>>> dict['list'].append([1,2,3,4])
>>> dict['list'].append([5,6,7])
>>> dict['list'].append([7,8,9,0,10])
输出字典：
>>> dict
{'list': [[1, 2, 3, 4], [5, 6, 7], [7, 8, 9, 0, 10]]}
>>> dict['list']
[[1, 2, 3, 4], [5, 6, 7], [7, 8, 9, 0, 10]]
相关操作：
>>> len(dict['lis
