Can't get iterator in the C API

[Jen Kris]

I am using the Python C API to load the Gutenberg corpus from the nltk library and iterate through the sentences.  The Python code I am trying to replicate is:

from nltk.corpus import gutenberg
for i, fileid in enumerate(gutenberg.fileids()):
        sentences = gutenberg.sents(fileid)
        etc

where gutenberg.fileids is, of course, iterable. 

I use the following C API code to import the module and get pointers:

int64_t Call_PyModule()
{
    PyObject *pModule, *pName, *pSubMod, *pFidMod, *pFidSeqIter,*pSentMod;

    pName = PyUnicode_FromString("nltk.corpus");
    pModule = PyImport_Import(pName);

    if (pModule == 0x0){
        PyErr_Print();
        return 1; }

    pSubMod = PyObject_GetAttrString(pModule, "gutenberg");
    pFidMod = PyObject_GetAttrString(pSubMod, "fileids");
    pSentMod = PyObject_GetAttrString(pSubMod, "sents");

    pFidIter = PyObject_GetIter(pFidMod);
    int ckseq_ok = PySeqIter_Check(pFidMod);
    pFidSeqIter  = PySeqIter_New(pFidMod);

    return 0;
}

pSubMod, pFidMod and pSentMod all return valid pointers, but the iterator lines return zero: 

pFidIter = PyObject_GetIter(pFidMod);
int ckseq_ok = PySeqIter_Check(pFidMod);
pFidSeqIter  = PySeqIter_New(pFidMod);

So the C API thinks gutenberg.fileids is not iterable, but it is.  What am I doing wrong?