[Python-Dev] Warning Framework (PEP 230)

[Guido van Rossum]

> > > How about returning 1 for 'warning turned into exception' and -1 for 'normal
> > > exception' ? It would be slightly more similar to other functions if '-1'
> > > meant 'exception', and it would be easy to put in an if statement -- and
> > > still allow C code to ignore the produced error, if it wanted to.
> 
> > Why would you want this?  The user clearly said that they wanted the
> > exception!
> 
> The difference is that in one case, the user will see the original
> warning-turned-exception, and in the other she won't -- the warning will be
> lost. At best she'll see (by looking at the traceback) the code intended to
> give a warning (that might or might not have been turned into an exception)
> and failed.

Yes -- this is a standard convention in Python.  if there's a bug in
code that is used to raise or handle an exception, you get a traceback
from that bug.

> The warning code might decide to do something aditional to
> notify the user of the thing it intended to warn about, which ended up as a
> 'real' exception because of something else.

Nah.  The warning code shouldn't worry about that.  If there's a bug
in PyErr_Warn(), that should get top priority until it's fixed.

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