if (!PyArg_ParseTuple(args, "")) return NULL;   again: n = a->nnz; list = PyList_New(n); if (list == NULL) return NULL; if (n != a->nnz) {  Py_DECREF(list); goto again; }  if (!a->issym) { for (i = 0; i < a->dim[0]; i ++) {
if ((list = PyList_New(a->nnz)) == NULL) return NULL;  for (i = 0; i < a->dim[0]; i ++) {
LLMat_keys(register LLMatObject *a, PyObject *args){        register PyObject *list;   /* the list that will hold the keys */	register int i, j, k;	int n;	int pos = 0;  /* position in list */	if (!PyArg_ParseTuple(args, ""))	  return NULL;  again:	n = a->nnz;	list = PyList_New(n);	if (list == NULL)		return NULL;	if (n != a->nnz) {	  /* (A little exception handler from the Python 2.4 source code.) */		Py_DECREF(list);		goto again;	}	if (!a->issym) {	  for (i = 0; i < a->dim[0]; i ++) {	    k = a->root[i];	    while (k != -1) {	      j = a->col[k];	      	      PyList_SetItem(list, pos++, Py_BuildValue("(OO)", PyInt_FromLong(i), PyInt_FromLong(j)));	      /* edvalue = SpMatrix_LLMatGetItem(a, i, j); */	      k = a->link[k];	    }	  }	} else {	  PyErr_SetString(PyExc_NotImplementedError, 			  "keys() doesn't yet support symmetric matrices");	  return NULL;	}	return list;}