Mr.Rech wrote: > All in all it seems that the implementation that uses isinstance() is > better in this case...
Well what's "better" depends on what you want to happen when you compare an unrelated class that also defines 'an_attribute'. Unlike in statically typed languages, certain things are made easier when you don't check for strict inheritance (like mock and proxy objects). Google "Duck Typing" for more info. -- http://mail.python.org/mailman/listinfo/python-list
