python-----deepcopy和copy的区别
话不多说,直接上代码
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.
个人拙见.如若有误,请不吝指出.共同进步.