Simon Bunker wrote: > Hi I have code similar to this: > > class Input(object): > > def __init__(self, val): > self.value = val > > def __get__(self, obj, objtype): > return self.value > > def __set__(self, obj, val): > # do some checking... only accept floats etc > self.value = val > > class Node(object): > > a = Input(1) > b = Input(2) > > I realise that a and b are now class attributes - however I want to do this: > > node1 = Node() > node2 = Node() > > node1.a = 3 > node.b = 4 > > And have them keep these values per instance. However now node1.a is 4 > when it should be 3. > > Basically I want to have the Input class as a gateway that does lots of > checking when the attibute is assigned or read. > > I have had a look at __getattribute__(), but this gets very ugly as I > have to check if the attribute is an Input class or not. > > Also I don't think property() is appropriate is it? All of the > attributes will essentially be doing the same thing - they should not > have individual set/get commands. > > Is there any way of doing this nicely in Python?
What about __setattr__ ? At least from your example, checking happens only when you set an attribute. If not, post a more representative sample of what you're trying to do. George -- http://mail.python.org/mailman/listinfo/python-list