PyArg_ParseTuple part 2

[Michael Hudson]

"John" <john.thai at dspfactory.com> writes:

> Hi,
> 
>     In an extended python c function, I use PyArg_ParseTuple to extract a
> list object from python.  I then use PyList_AsTuple to get a tuple version
> of the list.  I'm expecting an list of 2 integers, so I use PyArg_ParseTuple
> again, passing in this new derived tuple, and specifying "ii".  Should this
> not work?  First, after I call PyList_AsTuple, I get NULL back instead of a
> PyObject.  Second, lets say I pass variable x (from python) = [1,2] into my
> function, right after making this function call foo(x), no matter what I
> type, either x, or just enter, I get the following msg:
> 
> SystemError: C:\Code\python\dist\src\Objects\listobject.c:1317: bad argument
> to
> internal function
> 
> Anyone know what's going on?

Err, you are specifying your function as METH_VARARGS, right?  (Just a
guess).  Otherwise, how about showing us some code - I can't really
follow your description above.

> Related questions:  Is there a fast way of extracting elements from a list,
> other than using PyList_GetItem, then converting the PyObject into the type
> you are looking for?  

Well, there's PyList_GET_ITEM, but no, not really.  Lists store
PyObject*s - what were you expecting?

> And why isn't there a PyInt_FromInt(int) function?

There's PyInt_FromLong - is that what you're after?

Cheers,
M.

-- 
  Presumably pronging in the wrong place zogs it.
                                        -- Aldabra Stoddart, ucam.chat