A CSV parser in C using the Python csv standard module

c_csv_python_parser.c

#include <Python.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#define bail_null(obj) \
  if (NULL == obj) { err = 1; goto bail; }

#define bail_require(cond) \
  if (!(cond)) { err = 1; goto bail; }

static int try_python(const char* dbPath);

static int try_python(const char* dbPath) {
    int err = 0;
    PyObject *csvModule, *getReader, *dbFile, *reader;
    PyObject *pArgs, *iterator, *item;
    char fileName[1000] = {'\0'};
    char mode[] = "rbZ";

    strncpy(fileName, dbPath, sizeof(fileName));

    Py_Initialize();
    // https://docs.python.org/2.7/library/csv.html
    csvModule = PyImport_ImportModule("csv");
    bail_null_msg(csvModule, "Failed to import CSV parser modules");
    
    getReader = PyObject_GetAttrString(csvModule, "reader");
    bail_null(getReader);
    bail_require(PyCallable_Check(getReader));
    /* getReader is a new reference */

    dbFile = PyFile_FromString(fileName, mode);
    bail_null(dbFile);

    pArgs = PyTuple_New(1);
    bail_null(pArgs);

    PyTuple_SetItem(pArgs, 0, dbFile);

    reader = PyObject_CallObject(getReader, pArgs);
    bail_null(reader);
    bail_require(PyIter_Check(reader));

    iterator = PyObject_GetIter(reader);
    bail_null(iterator);

    while ((item = PyIter_Next(iterator))) {
        PyObject* iteratorString = PyObject_Str(item);
        const char* s = PyString_AsString(iteratorString);
        printf("%s\n", s);
        Py_DECREF(iteratorString);
        Py_DECREF(item);
    }

bail:
    if (reader) {
        Py_DECREF(reader);
    }
    if (dbFile) {
        Py_DECREF(dbFile);
    }
    if (getReader) {
        Py_XDECREF(reader);
    }
    if (csvModule) {
        Py_DECREF(csvModule);
    }
    if (err) {
        PyErr_Print();
    }
    Py_Finalize();
    return err;
}


int main(int argc, char *argv[]) {
  int err = 0;
  printf("test python CSV parser from C.\n");
  if (argc < 2 || NULL == argv[1]) {
    printf("You need to call this binary with a path to a CSV file.\n\n");
    err = 1;
  } else {
    err = try_python(argv[1]);
  }
  return err;
}