淺拷貝只拷貝最外層，裏層拷貝的是內存地址的引用
In [1]: import copy
In [41]: a1
Out[41]: [1, 2, 3, 4, {'k1': 'v1'}]
In [42]: a2 = copy.copy(a1)
In [43]: a2[4]['k1'] = 'v3'
In [44]: a2
Out[44]: [1, 2, 3, 4, {'k1': 'v3'}]
In [45]: a1
Out[45]: [1, 2, 3, 4, {'k1': 'v3'}]深拷貝數據都拷貝了
In [34]: a1
Out[34]: [1, 2, 3, 4, {'k1': 'v1'}]
In [35]: a3 = copy.deepcopy(a1)
In [36]: a3
Out[36]: [1, 2, 3, 4, {'k1': 'v1'}]
In [37]: a3[4]
Out[37]: {'k1': 'v1'}
In [38]: a3[4]['k1'] = 'v3'
In [39]: a3
Out[39]: [1, 2, 3, 4, {'k1': 'v3'}]
In [40]: a1
Out[40]: [1, 2, 3, 4, {'k1': 'v1'}]