PyInt_AsLong()

[Ralf Juengling]

"Fredrik Lundh" <fredrik at pythonware.com> writes:

> Ralf Juengling wrote:
> 
> > PyInt_AsLong() returns '-1´ to indicate an error, this meets the convetion
> > for PyXXX()-functions which return integers. But how do you distinguish an
> > '-1' indicating an error from a the legal long-value '-1'?
> 
> hint: when in doubt, grep the Modules directory in the
> Python source distribution:
> 
>     v = PyInt_AsLong(obj);
>     if (v == -1 && PyErr_Occurred())
>         return NULL; /* error */
>     /* v is valid */
> 
> hope this helps!
> 
> </F>

Okay. So the reason to indicate an error by '-1' is efficiency, 
I guess (i.e. calling PyErr_Occured() each time is more 
expensive than the prior check 'v == -1') ?

Thanks,
Ralf