c/c++再学习:C与Python相互调用

时间:2022-09-25 08:50:26

c/c++再学习:Python调用C函数

Python 调用C函数比较简单

这里两个例子,一个是直接调用参数,另一个是调用结构体

C代码

typedef struct {
int i1;
int i2;
char str[20];
} core_data_t; __declspec(dllexport) int add(int a, int b)
{
return a + b;
} __declspec(dllexport) int multi(int a, int b)
{
return a * b;
} __declspec(dllexport) int struct_add(core_data_t* data)
{
printf("%s\n", data->str);
return data->i1 + data->i2;
}

python代码

from ctypes import *

core = CDLL('core.dll')

add_val = core.add(1, 2)
multi_val = core.multi(2, 3) print(add_val)
print(multi_val) class CoreData(Structure):
_fields_ = [("i1", c_int),
("i2", c_int),
("str", c_char*20)] coredata = CoreData()
coredata.i1 = 10
coredata.i2 = 20
coredata.str = b"hello world"
coredata_ptr = byref(coredata)
struct_add_val = core.struct_add(coredata_ptr) print(struct_add_val)

结果

3
6
30
hello world

C调用python函数

c调用python,需要在增加<Python.h>和python36.lib,有时遇到编译时需要python36_d.lib时,只需要将python36.lib复制重命名为python36_d.lib放在同目录下即可

python代码

def py_print():
print("py_print") def py_add(a,b):
return a+b

c代码

#include "stdio.h"
#include "windows.h"
#include <Python.h> void main()
{
Py_Initialize();
PyObject* pModule = NULL;
PyObject* pFunc = NULL;
PyObject* pArgs = NULL;
PyObject* pValue = NULL; pModule = PyImport_ImportModule("python_demo");
pFunc = PyObject_GetAttrString(pModule, "py_print");
PyEval_CallObject(pFunc, NULL); pFunc = PyObject_GetAttrString(pModule, "py_add");
pArgs = PyTuple_New(2); PyTuple_SetItem(pArgs, 0, Py_BuildValue("i", 5));
PyTuple_SetItem(pArgs, 1, Py_BuildValue("i", 10)); pValue = PyEval_CallObject(pFunc, pArgs);
int res = 0;
PyArg_Parse(pValue, "i", &res);
printf("res %d\n", res); Py_Finalize();
return;
}

结果

py_print
res 15