Similarly I would ask then, why would you want to set class attributes on the built-in Exception classes?
On Dec 11, 2007, at 9:29 PM, Nishkar Grover wrote: > > I'm trying to replace the built-in base exception class with a > subclass of itself in python 2.5 because we can no longer add > attributes to that... > > % python2.4 -c 'import exceptions; exceptions.Exception.bar = 1234' > > % python2.5 -c 'import exceptions; exceptions.Exception.bar = 1234' > Traceback (most recent call last): > File "<string>", line 1, in <module> > TypeError: can't set attributes of built-in/extension type > 'exceptions.Exception' > > % python2.5 -c 'import exceptions; exceptions.BaseException.bar = > 1234' > Traceback (most recent call last): > File "<string>", line 1, in <module> > TypeError: can't set attributes of built-in/extension type > 'exceptions.BaseException' > > I already have a way to programatically construct the hierarchy of > subclasses, so for example, my subclass of OSError is a subclass of > the built-in OSError and a subclass of my subclass of > EnvironmentError. The only thing left to do is find a way to > replace the built-in exception types with my custom ones. > > - Nishkar > > > Calvin Spealman wrote: >> Why would you do this? How to do it, if its even possible, is far >> less >> important than if you should even attempt it in the first place. >> On Dec 11, 2007, at 3:51 PM, Nishkar Grover wrote: >>> >>> I'm trying to replace a built-in exception type and here's a >>> simplified >>> example of what I was hoping to do... >>> >>> >>> >>> >>> import exceptions, __builtin__ >>> >>> >>> >>> zeroDivisionError = exceptions.ZeroDivisionError >>> >>> >>> >>> class Foo(zeroDivisionError): >>> ... bar = 'bar' >>> ... >>> >>> >>> >>> exceptions.ZeroDivisionError = Foo >>> >>> ZeroDivisionError = Foo >>> >>> __builtin__.ZeroDivisionError = Foo >>> >>> >>> >>> try: >>> ... raise ZeroDivisionError >>> ... except ZeroDivisionError, e: >>> ... print e.bar >>> ... >>> bar >>> >>> >>> >>> try: >>> ... 1/0 >>> ... except ZeroDivisionError, e: >>> ... print e.bar >>> ... >>> Traceback (most recent call last): >>> File "<stdin>", line 2, in ? >>> ZeroDivisionError: integer division or modulo by zero >>> >>> >>> >>> Notice that I get my customized exception type when I explicitly >>> raise >>> ZeroDivisionError but not when that is implicitly raised by 1/0. It >>> seems like I have to replace that exception type at some lower >>> level, >>> but I'm not sure how/where. Does anyone know of a way to do this? >>> >>> - Nishkar >>> >>> --http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
