C API : setting the message of an exception

[Benoit Dejean]

(sorry for my english)

when an excpetion is raised (like Overflow), before i return NULL, i'd
like to modify the message held by the exception. I use PyErr_SetString ,
but i don't know how to retreive the current message

excaption is raised -> extending error message -> raising exception

thank you

[Thomas Heller]

Re: C API : setting the message of an exception

Benoit Dejean <bnet@ifrance.c om> writes:
[color=blue]
> (sorry for my english)
>
> when an excpetion is raised (like Overflow), before i return NULL, i'd
> like to modify the message held by the exception. I use PyErr_SetString ,
> but i don't know how to retreive the current message
>
> excaption is raised -> extending error message -> raising exception
>
> thank you[/color]

I have used this code:

void Extend_Error_In fo(char *fmt, ...)
{
va_list vargs;
PyObject *tp, *v, *tb, *s;

va_start(vargs, fmt);
s = PyString_FromFo rmatV(fmt, vargs);
va_end(vargs);
if (!s)
return;

PyErr_Fetch(&tp , &v, &tb);
PyString_Concat AndDel(&s, v);
PyErr_Restore(t p, s, tb);
}

and then you can:

if (result == NULL) {
Extend_Error_In fo("I wasn't expecting %s", "the spanish inquisition");
}

although I'm not sure what happens when PyString_FromFo rmatV() fails.

Thomas