python中的property属性

python中使用property属性有两种方法。使用@property装饰器和使用property()函数。

@property装饰器

@property装饰器就是负责把一个方法变成属性调用的。如下实例就可以通过s.score来获得成绩，并且对score赋值之前做出了数据检查。 

class C(object):
    def __init__(self):
        self._x = 9988

    @property
    def x(self):
        """I'm the 'x' property."""
        return self._x

    @x.setter
    def x(self, value):
        self._x = value

    @x.deleter
    def x(self):
        del self._x
c=C()
print(c.x)
c.x=10000
print(c.x)
del c.x
print(c.x)

Traceback (most recent call last):
  File "C:/Users/Administrator.SC-201903160419/Desktop/note/exer/1.py", line 122, in <module>
    print(c.x)
  File "C:/Users/Administrator.SC-201903160419/Desktop/note/exer/1.py", line 108, in x
    return self._x
AttributeError: 'C' object has no attribute '_x'
9988
10000

 

property()函数

语法

property([fget[, fset[, fdel[, doc]]]])

参数

• fget -- 获取属性值的函数
• fset -- 设置属性值的函数
• fdel -- 删除属性值函数
• doc -- 属性描述信息

返回值

返回新式类属性。

class C(object):
    def __init__(self):
        self._x = 9999

    def getx(self):
        return self._x

    def setx(self, value):
        self._x = value

    def delx(self):
        del self._x

    x = property(getx, setx, delx, "I'm the 'x' property.")
c=C()
print(c.x)
c.x=10000
print(c.x)
del c.x
print(c.x)

9999
10000
Traceback (most recent call last):
  File "C:/Users/Administrator.SC-201903160419/Desktop/note/exer/1.py", line 143, in <module>
    print(c.x)
  File "C:/Users/Administrator.SC-201903160419/Desktop/note/exer/1.py", line 129, in getx
    return self._x
AttributeError: 'C' object has no attribute '_x'

如果 c 是 C 的实例化, c.x 将触发 getter,c.x = value 将触发 setter ， del c.x 触发 deleter。