Python file to run from C++ code

Question

I am using Python 3.3. I am using C++ Qt code and embedding python into it. I want to execute one python file using C Python API in Python 3.

Below is sample code i am using to read the file and execute using Qt.

FILE *cp = fopen("/tmp/my_python.py", "r");
if (!cp)
{ 
 return;
}
Py_Initialize();
// Run the python file
#ifdef PYTHON2
PyObject* PyFileObject = PyFile_FromString("/tmp/my_python.py", (char *)"r");
if (PyRun_SimpleFile(PyFile_AsFile(PyFileObject), "/tmp/my_python.py") != 0)
 setError(tr("Failed to launch the application server, server thread exiting."));
#else
int fd = fileno(cp);
PyObject* PyFileObject = PyFile_FromFd(fd, "/tmp/my_python.py", (char *)"r", -1, NULL, NULL,NULL,1);
if (PyRun_SimpleFile(fdopen(PyObject_AsFileDescriptor(PyFileObject),"r"), "/tmp/my_python.py") != 0)
 setError(tr("Failed to launch the application server, server thread exiting."));
#endif
Py_Finalize();

For Python2 everything is working fine. But for python3(#else part) is not working under windows. Application is getting crashed. I do not want to read line by line and execute.

Can anyone give me guidance how to execute python file in C++ application using Python3 ? Some pseudo code or link will be helpful.

Thanks in Advance.

• Ignacio Vazquez-Abrams: Why are you not just passing cp instead of trying to be clever?
• Neel: You mean to say to call "if (PyRun_SimpleFile(cp, "/tmp/my_python.py")) right? This also i have tried but same result.
• Ignacio Vazquez-Abrams: docs.python.org/3/c-api/veryhigh.html#c.PyRun_SimpleFile

Answer 1

The following test program works fine passing the FILE pointer in directly for me.

runpy.c

#include <stdio.h>
#include <Python.h>
int main(int argc, char** argv)
{
 if (argc != 2)
 {
 printf("Usage: %s FILENAME\n", argv[0]);
 return 1;
 }
 FILE* cp = fopen(argv[1], "r");
 if (!cp)
 {
 printf("Error opening file: %s\n", argv[1]);
 return 1;
 }
 Py_Initialize();
 int rc = PyRun_SimpleFile(cp, argv[1]);
 fclose(cp);
 Py_Finalize(); 
 return rc;
}

Compiled on Fedora 23 with:

g++ -W -Wall -Wextra -I/usr/include/python3.4m -o runpy runpy.c -lpython3.4m