python装饰器@property

@property可以将python定义的函数“当做”属性访问，从而提供更加友好访问方式，但是有时候setter/deleter也是需要的。
1、只有@property表示只读。
2、同时有@property和@*.setter表示可读可写。

3、同时有@property和@*.setter和@*.deleter表示可读可写可删除。

class A(object):  # 要求继承object
    def __init__(self):
        self.__name = None

    # 下面开始定义属性，3个函数的名字要一样！
    @property  # 读
    def name(self):
        return self.__name

    @name.setter  # 写
    def name(self, value):
        self.__name = value

    @name.deleter  # 删除
    def name(self):
        del self.__name


a = A()
print(a.name ) # 读
a.name = 'python'  # 写
print(a.name ) # 读
del a.name  # 删除
print(a.name) # a.name已经被删除 AttributeError: 'A' object has no attribute '_A__name'

运行结果：

F:\dev\python\python.exe F:/pyCharm/practice/config_dir/property_demo2.py
None
Traceback (most recent call last):
python
File "F:/pyCharm/practice/config_dir/property_demo2.py", line 24, in <module>
print(a.name) # a.name已经被删除 AttributeError: 'A' object has no attribute '_A__name'
File "F:/pyCharm/practice/config_dir/property_demo2.py", line 8, in name
return self.__name
AttributeError: 'A' object has no attribute '_A__name'

Process finished with exit code 1