With reference to my previous posting http://mail.python.org/pipermail/c++-sig/2005-February/008585.html and this section in the Boost.Pyton documentation http://www.boost.org/libs/python/doc/tutorial/doc/html/python/techniques.htm... Here is a neat alternative based on Python 2.4 decorators: # general purpose helper for injecting attributes class injector: def __init__(self, obj, attr): self.obj = obj self.attr = attr def __call__(self, attr_obj): setattr(self.obj, self.attr, attr_obj) class point: def __init__(self, (x,y)): self.xy = (x,y) @injector(point, "__str__") def attr_obj(self): return str(self.xy) p = point((1,2)) print p I am not sure about all the pros and cons compared to the BoostPythonMetaclass approach shown in the Boost.Python documentation, but at least I find it easier to understand and the injector is completely independent of Boost.Python. Cheers, Ralf __________________________________ Do you Yahoo!? The all-new My Yahoo! - What will yours do? http://my.yahoo.com