Repository navigation
请教关于引用的一个问题 #98
Description
Activity
In [13]: a = [9, 7, 5, 3, 1] In [14]: b = a In [15]: b Out[15]: [9, 7, 5, 3, 1] In [16]: a.reverse() In [17]: a Out[17]: [1, 3, 5, 7, 9] In [18]: b Out[18]: [1, 3, 5, 7, 9]
上面的a和b其实是指向的同一个内存地址，修改任一个的值，都会影响到另一个。
In [26]: a.__str__ Out[26]: <method-wrapper '__str__' of list object at 0x7fc1f7f68988> In [27]: b.__str__ Out[27]: <method-wrapper '__str__' of list object at 0x7fc1f7f68988>
下面是n是m的拷贝，m、n内存地址不同。
In [24]: m.__str__ Out[24]: <method-wrapper '__str__' of list object at 0x7fc1f7f6fdc8> In [25]: n.__str__ Out[25]: <method-wrapper '__str__' of list object at 0x7fc1f7e6bdc8>
In [19]: m = [0, 2, 4, 6, 8] In [20]: n = m.copy() In [21]: m.reverse() In [22]: m Out[22]: [8, 6, 4, 2, 0] In [23]: n Out[23]: [0, 2, 4, 6, 8]
再深一点就是__深拷贝和浅拷贝__了
个人愚见。有道理。很多高级语言，都是将某些基本类型和由基本类型组合的类型，以不同的存储方式处理。
2016-05-05 17:04 GMT+08:00 lambdaplus notifications@github.com:
In [13]: a = [9, 7, 5, 3, 1]
In [14]: b = a
In [15]: b
Out[15]: [9, 7, 5, 3, 1]In [16]: a.reverse()
In [17]: a
Out[17]: [1, 3, 5, 7, 9]In [18]: b
Out[18]: [1, 3, 5, 7, 9]上面的a和b其实是指向的_同一个内存地址_，修改任一个的值，都会影响到另一个。
In [26]: a.str
Out[26]: <method-wrapper 'str' of list object at 0x7fc1f7f68988>In [27]: b.str
Out[27]: <method-wrapper 'str' of list object at 0x7fc1f7f68988>
下面是n是m的拷贝，m、n内存地址不同。
In [24]: m.str
Out[24]: <method-wrapper 'str' of list object at 0x7fc1f7f6fdc8>In [25]: n.str
Out[25]: <method-wrapper 'str' of list object at 0x7fc1f7e6bdc8>In [19]: m = [0, 2, 4, 6, 8]
In [20]: n = m.copy()
In [21]: m.reverse()
In [22]: m
Out[22]: [8, 6, 4, 2, 0]In [23]: n
Out[23]: [0, 2, 4, 6, 8]再深一点就是__深拷贝和浅拷贝__了
个人愚见。—
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub
#98 (comment)QiWei
谢谢！
