[Python-Dev] Pre-PEP: Exception Reorganization for Python 3.0

[Guido van Rossum]

On 7/29/05, Robert Brewer <fumanchu at amor.org> wrote:
> >     +-- SystemExit
> >     +-- SystemError (subclass SystemExit?)
> 
> I'd recommend not subclassing SystemExit--there are too many programs
> out there which expect the argument (e.g. sys.exit(3)) to mean something
> specific, but that expectation doesn't apply at all to SystemError.

Agreed. SystemExit is used by sys.exit(); SystemError is something
completely different, used by the interpreter when it finds an
internal invariant is broken. It is one step short of a fatal error --
the latter is used when we have evidence of random memory scribbling,
the former when the interpreter is still intact.

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)