multi-property groups?

[Ron Adam]

I was trying to see if I can implement property groups so I can set and 
pass arguemts as dictionaries.  I think this will simplify interfacing 
to multiple objects and funtions that use a lot of keywords as arguments.

But so far, the the following seems like it's not the most efficient way 
to do it.  So is there a better way?  Is there a way to use properties 
to do this same thing?

I'd also like a way to override the dictionary methods __getitem__, 
__setitem__, and __delitem__.  (Or an equivalent)


Cheers,
    Ron


class Pobject(object):
     """ an objects class that can have property groups """
     __props__ = {}
     def Properties(self, *args):
         dct = {}
         for i in args[1:]:
             dct.setdefault(i,None)
         self.__props__[args[0]]=dct
         return dct
     def __getattr__(self, name):
         for dct in self.__props__:
             if name in self.__props__[dct]:
                 return self.__props__[dct].__getitem__(name)
         return self.__dict__[name]
     def __setattr__(self, name, value):
         for dct in self.__props__:
             if name in self.__props__[dct]:
                 self.__props__[dct].__setitem__(name,value)
                 return
         self.__dict__[name] = value

class shapes(Pobject):
     def __init__(self):
         self.A = self.Properties('A', 'square', 'triangle', 'cube')
         self.B = self.Properties('B', 'red', 'blue', 'green')
     def show(self, it):
         if it == 'shapes':
            self.pp(it, self.A)  # pass properties as groups!
         elif it == 'colors':
            self.pp(it, self.B)  # have several property groups!
         else:
            print "I have no %s.\n" % it
     def pp(self, it, obj):
         print '%s I have:' % it
         for item in obj.keys():
             print '  %s = %r'  % (item,obj[item])
         print

box = shapes()
box.square = 10
box.blue = 5
print box.square
print box.blue
print box.green
box.purple = 'violet'
print box.purple
print
box.show('shapes')
box.show('colors')
box.show('flowers')


10
5
None
violet

shapes I have:
   cube = None
   square = 10
   triangle = None

colors I have:
   blue = 5
   green = None
   red = None

I have no flowers.