At the moment, when a python function, like print, calls an object attribute it does this (if it were written in python):

type(obj).__str__(obj)

This can be restrictive in lots of situations and I think it would be better to just get the attribute from the object itself.

obj.__str__()

It would make you free to override it on a per object basis. In some cases, this could lead to huge optimization.

Obviously, it is easy to fix yourself, but it is a layer of uncharacteristic unintuitiveness:

def __str__(self):

self._str()