>本代码演示了c++调用python的各种参数转换例子，包括字符串，数值，数组，类，list等转换方法
>运行平台：vc2019,python37(64位)

代码下载地址:https://download.csdn.net/download/dcx_dcx/12170359

代码示例如下：

//1. 传送字符串和数据到python函数

void TestF1(void) 
{

    PyObject* pModule = NULL;
    PyObject* pFunc = NULL;
    PyObject* pArg = NULL;
    pModule = PyImport_ImportModule("demo1"); //注意文件名字大小写
    pFunc = PyObject_GetAttrString(pModule, "Hello");//获取函数名称
    pArg = Py_BuildValue("(s)", "my is c++ test!");  //一个字符串参数
    PyEval_CallObject(pFunc, pArg);//函数调用
    pFunc = PyObject_GetAttrString(pModule, "Add");  //两个整形的参数
    pArg = Py_BuildValue("(i,i)", 10, 25);  // 变量格式转换成python格式
    PyEval_CallObject(pFunc, pArg);
}

python文件: demo1.py

def Hello(s):
	print("\n=======================")
	print("demo1:hello")
	print(s)


def Add(a, b):
	print("\n=======================")
	print("demo1:add")
	print("{0}".format(a + b))
  

///
//2.列表作为参数的传送给python函数

void TestF2(void)
{
    PyObject* pModule = NULL;
    PyObject* pFunc = NULL;
    PyObject* pArg = NULL;

    pModule = PyImport_ImportModule("demo2"); //注意文件名字大小写
    PyObject* pyFunc_printList = PyObject_GetAttrString(pModule, "printList");//获取函数名称
    if (pModule && PyCallable_Check(pyFunc_printList))
    {
        PyObject* pyParams = PyList_New(0);           //初始化一个列表
        PyList_Append(pyParams, Py_BuildValue("d", 5));//列表添加元素值浮点数
        PyList_Append(pyParams, Py_BuildValue("i", 2));
        PyList_Append(pyParams, Py_BuildValue("i", 6));
        PyList_Append(pyParams, Py_BuildValue("i", 8));
        PyObject* args = PyTuple_New(1);              //定义一个python变量
        PyTuple_SetItem(args, 0, pyParams);// 变量格式转换成python格式
        PyEval_CallObject(pyFunc_printList, args);//函数调用
    }
}

python文件：demo2.py
def printList(l):
	print("\n=======================")
	print("demo2")
	print(len(l))
	print(l);

/
/
//3.python类的操作
/
void TestF3(void) 
{
    PyObject* pModule = NULL;
    PyObject* pFunc = NULL;
    PyObject* pArg = NULL;
    PyObject* pClass = NULL;
    PyObject* pObject = NULL;

    pModule = PyImport_ImportModule("demo3");               //注意文件名字大小写
    pClass = PyObject_GetAttrString(pModule, "Person");     //先获取类名
    pArg = PyTuple_New(1);  // 定义一个变量                                 
    PyTuple_SetItem(pArg, 0, Py_BuildValue("s", "Class:Jacky"));  // 变量格式转换成python格式
    pObject = PyEval_CallObject(pClass, pArg);              //根据类名实例化对象
    pFunc = PyObject_GetAttrString(pObject, "printName");   //根据对象得到成员函数
    PyEval_CallObject(pFunc, NULL);//函数调用
}


python文件：demo3.py

class Person:
       def __init__(self, name):
            self.name = name
       def printName(self):
           print("\n=======================")
           print("demo3")
           print (self.name)

/
/
//4. Python程序返回参数的例子
/

void TestF4(void)
{
    PyObject* pModule = PyImport_ImportModule("demo4");//注意文件名字大小写
    PyObject* pyFunc_mix = PyObject_GetAttrString(pModule, "mix");
    if (pModule && PyCallable_Check(pyFunc_mix))
    {
        PyObject* pyParams = PyTuple_New(2); //定义两个变量
        PyTuple_SetItem(pyParams, 0, Py_BuildValue("i", 5));// 变量格式转换成python格式
        PyTuple_SetItem(pyParams, 1, Py_BuildValue("i", 2));// 变量格式转换成python格式
        int r1 = 0, r2 = 0;
        PyObject* pyValue = PyObject_CallObject(pyFunc_mix, pyParams); //调用函数返回结果
        PyArg_ParseTuple(pyValue, "i|i", &r1, &r2);//分析返回的元组值
        if (pyValue)
        {
            printf("%d   %d\n", r1, r2);
        }
    }

}

python文件：demo4.py

def mix(a,b):
    print("\n=======================")
    print("demo4")       
    r1 = a + b
    r2 = a - b
    return (r1, r2)

///
//5.c++数组转python的list
/
void TestF5(void)
{
    //以下调用很重要，否则转换中会出现异常
    if (_import_array() < 0) 
    {

        PyErr_Print(); 

        PyErr_SetString(PyExc_ImportError, "numpy.core.multiarray failed to import"); 
    } 

   
    PyObject* pModule = NULL;
    PyObject* pFunc = NULL;

    pModule = PyImport_ImportModule("demo5");//注意文件名字大小写
    PyObject* pyFunc_printList = PyObject_GetAttrString(pModule, "printList");//获取函数名称

    float buf[2][3]; //定义二维数组
    buf[0][0] = 0;
    buf[0][1] = 1.233;
    buf[0][2] = 2.222;
    buf[1][0] = 4.222;
    buf[1][1] = 5.333;
    buf[1][2] = 6.333;

    PyObject* pArgs = PyTuple_New(1);
    npy_intp dims[2]={2,3}; //定义list的shape
    int ND = 2;//指明list的维度
    PyObject* pPyArray = PyArray_SimpleNewFromData(ND, dims, NPY_FLOAT, buf); //指明list的维度，shape,数量类型，缓冲区
    PyTuple_SetItem(pArgs, 0, pPyArray);//变量转换
    PyEval_CallObject(pyFunc_printList, pArgs);//函数调用
 }


python文件:demo5.py

def printList(lis):
	print("\n=======================")
	print("demo5")
	print(lis)