c++ 调用python

compile.sh

g++ new.cpp  -I/usr/include/python2.4  -fPIC -lpython2.4

main.cpp

#include <Python.h>
#include <iostream>
#include <string>
using namespace std;
bool calc(const string& filename, char* methodname, const string& expression, double& result)
{
    PyObject *pyFileName = PyString_FromString(filename.c_str());
    PyObject *pyMod = PyImport_Import(pyFileName); // load the module
    if(pyMod) // if ok
    {
        // load the function
        PyObject *pyFunc = PyObject_GetAttrString(pyMod, methodname);
        if(pyFunc && PyCallable_Check(pyFunc))
        {
            PyObject *pyParams = PyTuple_New(1);
            PyObject *pyValue = PyString_FromString(expression.c_str());
            PyTuple_SetItem(pyParams, 0, pyValue);
            // ok, call the function
            pyValue = PyObject_CallObject(pyFunc, pyParams);
            if(pyValue)
            {
                result = PyFloat_AsDouble(pyValue);
                return true;
            }
            else
            {
                return false;
            }
        }
        else
        {
            return false;
        }
    }
    else
    {
        return false;
    }
    return false;
}
int main(int argc, char *argv[])
{
    string filename = "python_code"; // file name is settled!
    string inputParam = "Hello World"; // get user input!
    double result = 0.0;

    Py_SetProgramName(argv[0]);
    Py_Initialize();
    PySys_SetArgv(argc, argv);

    if(calc(filename, "calculate", inputParam, result))
    {
        printf("/nResult is : %lf/n", result);
    }

    Py_Finalize();
}

python_code.py

def calculate(expression):
    try:
        # result = eval(expression)
        print expression
    except:
        print 'Eval error!'
        return -1.0
    return 1.0