If you want to solve the problem in the definition of the class of myobject (like in Black Diamond's answer) you can simply define __getattr__ to return None:
class Myobject:
def __getattr__(self, name):
return None
This works because __getattr__ is only called when trying to access an attribute that does not exist, whereas __getattribute__ is always called first no matter the name of the attribute. (See also this SO post.)
To try out:
myobject = Myobject()
print myobject.id
myobject.id = 7
print myobject.id
