[Python-Dev] Python/import.c

[Jiwon Seo]

It looks like it's because even if the package failed to be loaded, it 
should be added to its parent module dict, IMHO.
The comment in the import.c::add_submodule describes the behavior. I 
don't know how it could be useful, but I think it's the way import behaves.

...
static int
add_submodule(PyObject *mod, PyObject *submod, char *fullname, char 
*subname,
          PyObject *modules)
{
    if (mod == Py_None)
        return 1;
    /* Irrespective of the success of this load, make a
       reference to it in the parent package module.  A copy gets
       saved in the modules dictionary under the full name, so get a
       reference from there, if need be.  (The exception is when the
       load failed with a SyntaxError -- then there's no trace in
       sys.modules.  In that case, of course, do nothing extra.) */
...


Jiwon