C++调用返回多个值的Python函数

deles

某些时候，用python模块来实现一些特定的功能会比用其他类型的模块更加简洁方便。
在C++程序中，调用python模块时需要加载一些必要的libs，这些libs在网上都可以找到。下面的代码演示了C++程序如何调用python中的函数，并得到从python函数中返回的多个值。

# filename : cal.py
# return type : tuple
def mix(a, b) :
r1 = a + b
r2 = a - b
return (r1, r2) # (7,3)


#include "stdafx.h"
#include ".\\include\\Python.h"
int _tmain(int argc, _TCHAR* argv[])
{
string filename = "cal"; // cal.py
string methodname_mix = "mix"; // function name
Py_Initialize();  
// load the module
PyObject * pyFileName = PyString_FromString(filename.c_str());
PyObject * pyMod = PyImport_Import(pyFileName);
// load the function
PyObject * pyFunc_mix = PyObject_GetAttrString(pyMod, methodname_mix.c_str());
// test the function is callable
if (pyFunc_mix && PyCallable_Check(pyFunc_mix))
{
PyObject * pyParams = PyTuple_New(2);
PyTuple_SetItem(pyParams, 0, Py_BuildValue("i", 5));
PyTuple_SetItem(pyParams, 1, Py_BuildValue("i", 2));
// ok, call the function
int r1 = 0, r2 = 0;
PyObject * pyValue = PyObject_CallObject(pyFunc_mix, pyParams);
PyArg_ParseTuple(pyValue, "i|i", &r1, &r2);
if (pyValue)
{
printf("%d,%d\n", r1, r2); //output is 7,3
}
}
Py_Finalize();  
return 0;
}