python学习日记

1、数值拷贝

import copy# ######数字、字符串######n1 = 123print(id(n1))n2 = n1print(id(n2))###浅拷贝###n2 = copy.copy(n1)print(id(n2))###深拷贝###n3 = copy.deepcopy(n1)print(id(n3))

C:Users811314AppDataLocalProgramsPythonPython35-32python.exe C:/homework/day3/1.py
492322480
492322480
492322480
492322480

Process finished with exit code 0

2、字符串

import copy# ######数字、字符串######n1 = "my name is hellworld"print(id(n1))n2 = n1print(id(n2))###浅拷贝###n2 = copy.copy(n1)print(id(n2))###深拷贝###n3 = copy.deepcopy(n1)print(id(n3))

C:Users811314AppDataLocalProgramsPythonPython35-32python.exe C:/homework/day3/1.py
5973920
5973920
5973920
5973920

立即学习“Python免费学习笔记（深入）”；

Process finished with exit code 0

import copy# ######数字、字符串######n1 = ["helloworld","hapen"]print(id(n1))n2 = n1print(id(n2))###浅拷贝###n2 = copy.copy(n1)print(id(n2))###深拷贝###n3 = copy.deepcopy(n1)print(id(n3))

C:Users811314AppDataLocalProgramsPythonPython35-32python.exe C:/homework/day3/1.py
12817912
12817912
10370784
12816672

Process finished with exit code 0

对于 数字 和 字符串 而言，赋值、浅拷贝和深拷贝无意义，因为其永远指向同一个内存地址。

 浅拷贝，在内存中只额外创建第一层数据

深拷贝，在内存中将所有的数据重新创建一份（排除最后一层，即：python内部对字符串和数字的优化

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