[Python知识库]Python-内置函数-property

使用场景一

class Test:
    def __init__(self):
        self._x = None

    def getx(self):
        print(f'{__class__}-{sys._getframe().f_code.co_name}开始执行')
        return self._x

    def setx(self, value):
        print(f'{__class__}-{sys._getframe().f_code.co_name}开始执行')
        self._x = value
        print(f'{__class__}-{sys._getframe().f_code.co_name}结束执行')

    def delx(self):
        print(f'{__class__}-{sys._getframe().f_code.co_name}开始执行')
        del self._x

    x = property(getx,setx,delx,"x property")

if __name__ == '__main__':
    t1 = Test()
    print(t1.x)  # .号会直接触发getx方法
    t1.x = 11    # .号=value 触发setx方法
    print(t1.x)  
    del t1.x     # del 触发delx方法
    print(t1.x)
"""
<class '__main__.Test'>-getx开始执行
None
<class '__main__.Test'>-setx开始执行
<class '__main__.Test'>-setx结束执行
<class '__main__.Test'>-getx开始执行
11
<class '__main__.Test'>-delx开始执行
<class '__main__.Test'>-getx开始执行
AttributeError: 'Test' object has no attribute '_x'
"""

使用场景二

class Test2:
    def __init__(self):
        self._x = None

    @property
    def x(self):
        return self._x

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

    @x.deleter
    def delx(self):
        del self._x

if __name__ == '__main__':
    t2 = Test2()
    print(t2.x)
    t2.setx = 12
    print(t2.x)
    del t2.delx
    print(t2.x)

"""
None
12
AttributeError: 'Test2' object has no attribute '_x'
"""