python中的property

property(fget=None, fset=None, fdel=None, doc=None) -> property attribute

fget is a function to be used for getting an attribute value, and likewise
fset is a function for setting, and fdel a function for del‘ing, an
attribute.  Typical use is to define a managed attribute x:

class C(object):
    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.")

Decorators make defining new properties or modifying existing ones easy:

class C(object):
    @property
    def x(self):
        "I am the ‘x‘ property."
        return self._x
    @x.setter
    def x(self, value):
        self._x = value
    @x.deleter
    def x(self):
        del self._x

class haha:
    def __init__(self):
        self.__x=‘weidiao‘
    @property
    def x(self):
        print("x.property")
        return self.__x
    @x.getter
    def x(self):
        print("x.getter")
        return self.__x
    @x.setter
    def x(self,x):
        print("x.setter")
        self.__x=x
    @x.deleter
    def x(self):
        print(‘x.deleter‘)
        del self.__x
a=haha()
print(a.x)
a.x=‘haha‘
print(a.x)
del a.x
print(a.x)

x.getter
weidiao
x.setter
x.getter
haha
x.deleter
x.getter
Traceback (most recent call last):
  File "C:/Users/weidiao/Documents/PycharmProjects/python实验室/main2.py", line 25, in <module>
    print(a.x)
  File "C:/Users/weidiao/Documents/PycharmProjects/python实验室/main2.py", line 11, in x
    return self.__x
AttributeError: ‘haha‘ object has no attribute ‘_haha__x‘