C extension module doesn't throw exception after setting error indicator through PyErr_SetString()

[Tim Golden]

On 02/08/2012 10:21, rahul wrote:
> 
> Hi TJG,
> 
> The above link also doesn't strictly said that return value should be
> NULL only, it only said that usually NULL pointer used. No where I
> saw that it is nessasory t
> 
> At http://docs.python.org/c-api/exceptions.html. it is written that
> "Most functions also return an error indicator, usually NULL if they
> are supposed to return a pointer, or -1 if they return an integer
> (exception: the PyArg_*() functions return 1 for success and 0 for
> failure)." this also told that usually NULL is used but we can change
> the return error indicator to any value. As like PyArg_*() used 0 for
> error value.

The docs you quote are very slightly confusing because they're combining
the standard practice (return NULL), the uncommon alternative (return
-1) and a few special cases present in the core functions.

In short, any function you expose in an extension module will be
returning a PyObject* and should return NULL if it is setting or
cascading an exception.

I'm not convinced that the docs need altering here: this is the first
time I've come across anyone who was confused. But if you think some
different wording might help, feel free to propose something.

TJG