>>>>> "Emanuele D'Arrigo" <man...@gmail.com> (ED) wrote:
>ED> Hi Everybody! >ED> I just tried this: >>>>> class C(object): >ED> ... def method(self): >ED> ... pass >ED> ... >>>>> c = C() >>>>> delattr(c, "method") >ED> Traceback (most recent call last): >ED> File "<stdin>", line 1, in <module> >ED> AttributeError: 'C' object attribute 'method' is read-only >ED> How come? Who told the class to make the method read-only? I didn't! Methods in a class are done with the descriptor protocol. All access to the method through an instance is executed via the descriptor. The delete calls the __delete__ method of the descriptor which isn't implemented for functions. See http://docs.python.org/reference/datamodel.html?highlight=descriptor#implementing-descriptors (Actually, IIRC, the function object is its own descriptor) >>> class C(object): ... def method(self): ... pass ... >>> c=C() >>> C.__dict__['method'] <function method at 0xd2330> >>> C.__dict__['method'].__get__ <method-wrapper '__get__' of function object at 0xd2330> >>> C.__dict__['method'].__delete__ Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'function' object has no attribute '__delete__' >>> -- Piet van Oostrum <p...@cs.uu.nl> URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
