Python 2.4.1 (#2, Aug 25 2005, 18:20:57) [GCC 4.0.1 (4.0.1-2mdk for Mandriva Linux release 2006.0)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> class X: ... def toto(self): ... print "X toto" ... >>> class Y(X): ... def toto(self): ... print "Y toto" ... def titi(self): ... print "titi" ... >>> test = X() >>> test2 = Y() >>> test2.toto() Y toto >>> test2.titi() titi >>> test.toto() X toto >>> test.titi() Traceback (most recent call last): File "", line 1, in ? AttributeError: X instance has no attribute 'titi' >>> J'en pense donc qu'il dit n'importe quoi. Pareil avec les new-style classes.