python深浅拷贝

code

import copy
 
age = 19
print(f'first:{id(age)}')
age = 20
print(f'second:{id(age)}')
 
 
l1 = ['a', 'b', 'c', ['d', 'e', 'f']]
l2 = l1
 
 
print("*"*25,"赋值","*"*25)
l1.append('g')
print("l1:",l1)
print("l2:",l2)
 
 
l1 = ['a', 'b', 'c', ['d', 'e', 'f']]
l2 = copy.copy(l1)
 
 
print("*"*25,"浅拷贝-修改不可变元素","*"*25)
l1.append('g')
print("l1:",l1)
print("l2:",l2)
 
 
print("*"*25,"浅拷贝-修改可变元素","*"*25)
l1[3].append('g')
print("l1:",l1)
print("l2:",l2)
 
 
l1 = ['a', 'b', 'c', ['d', 'e', 'f']]
l2 = copy.deepcopy(l1)
 
 
print("*"*25,"深拷贝-修改不可变元素","*"*25)
l1.append('g')
print("l1:",l1)
print("l2:",l2)
 
 
print("*"*25,"深拷贝-修改可变元素","*"*25)
l1[3].append('g')
print("l1:",l1)
print("l2:",l2)
 

Outputs

macname@MacdeMacBook-Pro py % python3 cccccc.py
first:4525530480
second:4525530512
************************* 赋值 *************************
l1: ['a', 'b', 'c', ['d', 'e', 'f'], 'g']
l2: ['a', 'b', 'c', ['d', 'e', 'f'], 'g']
************************* 浅拷贝-修改不可变元素 *************************
l1: ['a', 'b', 'c', ['d', 'e', 'f'], 'g']
l2: ['a', 'b', 'c', ['d', 'e', 'f']]
************************* 浅拷贝-修改可变元素 *************************
l1: ['a', 'b', 'c', ['d', 'e', 'f', 'g'], 'g']
l2: ['a', 'b', 'c', ['d', 'e', 'f', 'g']]
************************* 深拷贝-修改不可变元素 *************************
l1: ['a', 'b', 'c', ['d', 'e', 'f'], 'g']
l2: ['a', 'b', 'c', ['d', 'e', 'f']]
************************* 深拷贝-修改可变元素 *************************
l1: ['a', 'b', 'c', ['d', 'e', 'f', 'g'], 'g']
l2: ['a', 'b', 'c', ['d', 'e', 'f']]
macname@MacdeMacBook-Pro py %