python中deepcopy和copy的区别

import copy
n1 = [1,2,[1,2,3],4,5]
n3 = copy.copy(n1)      #浅拷备
n3[1] = "copy"
print('n1=',n1)
print('n3=',n3)

******************
n1= [1, 2, [1, 2, 3], 4, 5]
n3= [1, 'copy', [1, 2, 3], 4, 5]
******************

import copy
n1 = [1,2,[1,2,3],4,5]
n3 = copy.copy(n1)       #浅拷备
n3[2][0] = "copy"
print('n1=',n1)
print('n3=',n3)

******************
n1= [1, 2, ['copy', 2, 3], 4, 5]
n3= [1, 2, ['copy', 2, 3], 4, 5]
******************
_________________________________
*********************************
_________________________________

import copy
n1 = [1,2,[1,2,3],4,5]
n3 = copy.deepcopy(n1)    #深拷备
n3[1] = "deepcopy"
print('n1=',n1)
print('n3=',n3)

********************
n1= [1, 2, [1, 2, 3], 4, 5]
n3= [1, 'deepcopy', [1, 2, 3], 4, 5]
**********************


import copy
n1 = [1,2,[1,2,3],4,5]
n3 = copy.deepcopy(n1)      #深拷备
n3[2][0] = "deepcopy"         
print('n1=',n1)
print('n3=',n3)

*************************
n1= [1, 2, [1, 2, 3], 4, 5]
n3= [1, 2, ['deepcopy', 2, 3], 4, 5]
*************************

从代码可以看出来.浅拷备和深拷备唯一的区别,就在于对可变类型的处理,其中,若执行浅拷备,则不会为可变类型开辟新的内存空间

如代码中体现,改变了n1[2][0]的值,就会同时改变n3[2][0]的值.反之,若执行深拷备,则会为可变类型开辟新内存空间,也就是,改变了n1[2][0]的值,不会改变n3[2][0]的值.