Trouble Passing Array of Strings (using Numeric) to C Extension Module

[Travis E. Oliphant]

goetzie wrote:
> I am using Python 2.4.1 and Numeric 23.8 and running on Windows XP.  I
> am passing a Numeric array of strings (objects) to a C Extension module
> using the following python code:

Numeric 23.8 is *very* old and unsupported.   Unless you absolutely have 
to use Numeric (then use 24.2), NumPy is a better choice for new code.

With that advice aside.  Let's see...

> 
> And here is the relevent code from my C Extension module:
> 
>    static PyObject * _StringArrayIn( PyObject *self, PyObject *args )
>    {
>       PyObject *pObject;  // input array
>       PyArrayObject *pArray;  // contiguous array
>       int iCount;
>       int iStride;
>       BOOL bString;
> 
>       if ( !PyArg_ParseTuple( args, "O", &pObject ) ) return NULL;
> 
>       if ( ( pArray = ( PyArrayObject * )PyArray_ContiguousFromObject(
> pObject, PyArray_OBJECT, 1, 1 ) ) == NULL ) return NULL;
> 
>       iCount = pArray->dimensions[0];
>       iStride = pArray->strides[0];
> 
>       bString = PyString_Check( ( PyObject * )( pArray->data ) );
> 

This is the problem.:

pArray->data should be interpreted as (PyObject **) -- an array of 
PyObject *'s,  and then de-referenced to get the PyObject * present at 
the first address

So.  this should work to check that the first entry in the array is a 
string:

PyString_Check( *( ( PyObject ** )( pArray->data ) ) );


By the way, NumPy has support for true string (and unicode) arrays (as 
well as object arrays like this)...

-Travis