一、拷贝
对数据的复制
1、基本数据的赋值涉及的变量内存地址变化：
1 a = [1,2,3,[2,3]] 2 b = a 3 b[3][1] = 22 4 print(a) 5 pring(b) 6 #此时，a和b指向的是同一个内存地址，所以修改其中一个，另一个也会改变
2、浅拷贝：只复制数据的第一层
1 a = [1,2,[3,4]] 2 b = a.copy() # b = a[:] 3 4 b[1] = 22 5 b[2][1] = 44 6 7 print(a) 8 print(b) 9 10 -------> 11 12 [1, 2, [3, 44]] 13 [1, 22, [3, 44]]
如图：
3、深拷贝：就是完全克隆一份，需要模块copy支持
示例：
1 信用卡的案例： 2 3 import copy 4 5 husband = ['jack',123,[1500,9000]] # 名字，卡号，信用额度，余额 6 7 wife = husband.copy() # wife = copy.copy(husband) 一样的也是浅拷贝 8 wife[0] = 'lucy' 9 wife[1] = 234 10 11 wife[2][1] -= 8000 12 13 print(husband,wife) #['jack', 123, [1500, 1000]] ['lucy', 234, [1500, 1000]] 14 15 16 husband = ['jack',123,[1500,9000]] 17 xiaosan = copy.deepcopy(husband) #深拷贝 18 xiaosan[0] = 'lilei' 19 xiaosan[1] = 345 20 xiaosan[2][1] -= 2000 21 print(husband,xiaosan) ['jack', 123, [1500, 9000]] ['lilei', 345, [1500, 7000]]
了解更多查看：http://www.cnblogs.com/yuanchenqi/articles/5782764.html