George Sakkis wrote: > 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
Yes, but I am setting it in the Node class aren't I? Wouldn't I need to define __setattr__() in class Node rather than class Input? I don't want to do this. Or am I getting confused here? thanks Simon -- http://mail.python.org/mailman/listinfo/python-list
