Python 类继承时覆盖类属性的问题 - V2EX
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plko345
V2EX    Python

Python 类继承时覆盖类属性的问题

  •  
  •   plko345 2024-02-07 17:00:58 +08:00 2037 次点击
    这是一个创建于 686 天前的主题,其中的信息可能已经有所发展或是发生改变。
    class Base(object): PRODUCT = 1 CLIENT = PRODUCT * 10 class Base1(Base): PRODUCT = 2 print(Base.CLIENT) print(Base1.CLIENT) 

    请问 Base1 的 CLIENT 要怎么才能变成 20, 不重复写 CLIENT 的表达式情况下

    10 条回复    2024-02-07 19:14:57 +08:00
    yingxiangyu
        1
    yingxiangyu  
       2024-02-07 17:03:14 +08:00
    没办法
    Leviathann
        2
    Leviathann  
       2024-02-07 17:05:25 +08:00
    改成 getter
    wkj89
        3
    wkj89  
       2024-02-07 17:10:04 +08:00
    2 楼说的对 覆写__attr__相关函数
    plko345
        4
    plko345/strong>  
    OP
       2024-02-07 17:13:44 +08:00
    @Leviathann
    @wkj89
    是改为 `print(getattr(Base1, 'CLIENT'))` 这样吗? 试了不行, 应该是我理解错了吧
    wkj89
        5
    wkj89  
       2024-02-07 17:25:56 +08:00
    覆写__getattr__ 函数 但是没啥意义 还不如重复定义 client
    error451
        6
    error451  
       2024-02-07 17:46:11 +08:00
    这么搞就不符合类设计的逻辑
    类静态变量,你却要求他是可变的, 为什么要这样呢?
    XIVN1987
        7
    XIVN1987  
       2024-02-07 17:54:15 +08:00
    ``` python
    class Base(object):
    PRODUCT = 1

    @property
    def CLIENT(self):
    return self.PRODUCT * 10


    class Base1(Base):
    PRODUCT = 2


    print(Base().CLIENT)
    print(Base1().CLIENT)
    ```
    plko345
        8
    plko345  
    OP
       2024-02-07 17:54:39 +08:00
    @error451 恩, 我想应该是我的设计有问题, 我把这部分移到类外部处理试试
    wkj89
        9
    wkj89  
       2024-02-07 17:58:32 +08:00
    @plko345
    你按 7 楼的方法就行
    Alias4ck
        10
    Alias4ck  
       2024-02-07 19:14:57 +08:00   1
    可以用描述器解决你的问题

    ```
    class ClientDescriptor:
    def __get__(self, instance, owner):
    return owner.PRODUCT * 10
    class Base(object):
    PRODUCT = 1
    CLIENT = ClientDescriptor()
    class Base1(Base):
    PRODUCT = 2

    ```
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