I have a class (actually implemented in c++ using boost::python). For an instance of this class, 'r', I'd like to support len (r). I don't want to add it to the c++ code, because this is a unique situation: this class should not normally support len().
So I try: r = ring_int (10) r.__len__ = lambda: 10 This doesn't work: >>> len(r) TypeError: object of type 'ring_int' has no len() It appears that __len__ is being looked up only on the class dict, not the instance dict? What's the correct way to do this? (Of course, I could just use inheritance, but this is an opportunity for me to learn more about python) -- http://mail.python.org/mailman/listinfo/python-list
