python 深拷贝_python 深拷贝

深拷贝是将对象全拷贝，包括嵌套对象

def deepcopy(cls):

if isinstance(cls, dict):

dct = {}

for k, v in cls.items():

dct[k] = deepcopy(v)

return dct

elif isinstance(cls, list):

li = []

for item in cls:

li.append(deepcopy(item))

return li

elif isinstance(cls, tuple):

li = []

for i in cls:

li.append(deepcopy(i))

return tuple(li)

else:

return cls

验证：

import copy

if __name__ == '__main__':

lst = [1, 2, 3, 6, 4, ([5, 6, 8, 7, [7, 8, {"acb": 89375, "dxt": "kgfjolij", "v": 222}, 5, 4, 7]], (2,5,{"z":2}))]

res = deepcopy(lst)

print(res,'deep',id(res[5][0]))

print('lst', id(lst[5][0]))

ls = copy.copy(lst)

print('ls', id(ls[5][0]))

#[1, 2, 3, 6, 4, ([5, 6, 8, 7, [7, 8, {'acb': 89375, 'dxt': 'kgfjolij', 'v': # 222}, 5, 4, 7]], (2, 5, {'z': 2}))] deep 42348296

# lst 42348168

# ls 42348168

代码简化：

def deepcopy(cls):

if isinstance(cls, dict):

return {k: deepcopy(v) for k, v in cls.items()}

elif isinstance(cls, list):

return [deepcopy(item) for item in cls]

elif isinstance(cls, tuple):

return tuple([deepcopy(item) for item in cls])

else:

return cls