[Python-Dev] when is path==NULL?

[Christian Heimes]

Ulrich Eckhardt wrote:
> Hi!
> 
> I'm looking at trunk/Python/sysmodule.c, function PySys_SetArgv(). In that 
> function, there is code like this:
> 
>   PyObject* path = PySys_GetObject("path");
>   ...
>   if (path != NULL) {
>     ...
>   }
> 
> My intuition says that if path==NULL, something is very wrong. At least I 
> would expect to get 'None', but never NULL, except when out of memory. So, 
> for the case that path==NULL', I would simply invoke Py_FatalError("no mem 
> for sys.path"), similarly to the other call there.

PySys_GetObject may return NULL after the user has removed sys.path with 
delattr(sys, 'path'). There are valid applications for removing sys.path.

Christian