不调用属性装饰器的setter方法
问题内容:
我正在尝试使用属性方法来设置具有以下类定义的类实例的状态:
class Result:
def __init__(self,x=None,y=None):
self.x = float(x)
self.y = float(y)
self._visible = False
self._status = "You can't see me"
@property
def visible(self):
return self._visible
@visible.setter
def visible(self,value):
if value == True:
if self.x is not None and self.y is not None:
self._visible = True
self._status = "You can see me!"
else:
self._visible = False
raise ValueError("Can't show marker without x and y coordinates.")
else:
self._visible = False
self._status = "You can't see me"
def currentStatus(self):
return self._status
从结果来看,尽管内部变量已更改,但似乎没有执行setter方法:
>>> res = Result(5,6)
>>> res.visible
False
>>> res.currentStatus()
"You can't see me"
>>> res.visible = True
>>> res.visible
True
>>> res.currentStatus()
"You can't see me"
我究竟做错了什么?
问题答案:
在Python 2上, 必须 继承自object
才能使属性起作用:
class Result(object):
使它成为一种新型的类。进行此更改后,您的代码将起作用:
>>> res = Result(5,6)
>>> res.visible
False
>>> res.visible = True
>>> res.currentStatus()
'You can see me!'