Perhaps this piece of code might explain the behaviour:
>>> class C( object ): ... __slots__ = () ... >>> o = C() >>> o.a = 1 Traceback (most recent call last): File "<input>", line 1, in ? AttributeError: 'C' object has no attribute 'a' object behaves like having an implict __slots__ attribute. HTH, Gerald Dale Strickland-Clark schrieb: > Python 2.4.2 (#1, Oct 13 2006, 17:11:24) > [GCC 4.1.0 (SUSE Linux)] on linux2 > Type "help", "copyright", "credits" or "license" for more information. > >>>>a = object() >>>>a > > <object object at 0xb7bbd438> > >>>>a.spam = 1 > > Traceback (most recent call last): > File "<stdin>", line 1, in ? > AttributeError: 'object' object has no attribute 'spam' > >>>>class b(object): > > ... pass > ... > >>>>a = b() >>>>a > > <__main__.b object at 0xb7b4dcac> > >>>>a.spam = 1 >>>> > > > What is subclassing adding to the class here? Why can't I assign to > attributes of an instance of object? -- http://mail.python.org/mailman/listinfo/python-list
