gistfile1.py

class myclass(object):
    def __init__(self):
        self._x = 5
    @property
    def x(self):
        return self._x
    @x.setter
    def x(self, value):
        self._x = value
    @x.deleter
    def x(self):
        del self._x


myobj = myclass()
print myobj.x
myobj.x = 20
print myobj.x
del myobj.x
try:print myobj.x
except:print "attribute has been deleted!"