C/C++调用python,opencv+python

c++中调用python 的属性配置

将python安装目录下的include和libs文件夹分别包含在VC++目录下，如下图：

c++中调用python 的实例

code 1:

#include   
#include   
using namespace std;

int main(int argc, char *argv[])
{
	Py_Initialize();
	PyRun_SimpleString("print 'Hello Python!'\n");
	Py_Finalize();
	return 0;
}

code2:

//.cpp调用pyhton .py文件
#include 
#include 
using namespace std;

int main()
{
	Py_Initialize();

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

	pModule = PyImport_ImportModule("py_test");
	if (!pModule){
		cout << "get module failed!" << endl;
		exit(0);
	}

	pFunc = PyObject_GetAttrString(pModule, "Hello");
	PyEval_CallObject(pFunc, NULL);

	Py_Finalize();

	return 0;
}

#py_test.py

def Hello():
    print "Hello, Jason"

下面是调用python脚本的一般步骤：

1.  windows VS环境，首先在C++的工程文件总增加python安装目录下的include(附加包含目录)和libs目录(附加库目录)。
2.  在需要用到python的C++文件中，添加#include "Python.h"
3.  引用python的代码部分，都需要以Py_Initialize()开始，用Py_Finalize()结束
4.  python相关的对象多半声明为PyObject指针，如PyObject *pstr, *pmod, *pdict, *pfunc, *pargs等
5.  最简单的调用一段python代码的方法：PyRun_SimpleString("...");
6. 导入一个模块：pModule= PyImport_ImportModule("script")  //script，脚本的名字调用其中的一个函数Hello( ) pfunc = PyObject_GetAttrString(pModule, "Hello");用指定的参数运行这个函数：PyEval_CallObject(pfunc, pargs);
7.  步骤6的另一种做法：导入一个模块：pname = PyString_FromString("script");    pModule = PyImport_Import(pname); 调用其中的函数pyPrint(name1, name2)pdict = PyModule_GetDict(pModule);        pfunc = PyDict_GetItemString(pdict, "pyPrint");   pargs = Py_BuildValue("s, s", "Hello World", "again");            运行这个函数：PyEval_CallObject(pfunc, pargs);注意，当py函数没有参数时，pargs = NULL
8. 释放PyObject 指针：Py_DECREF(pobj)
   

下面code3实例为python脚本带参数：

//python函数带参数

#include 
int main()
{
	Py_Initialize();

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

	pModule = PyImport_ImportModule("py_test2_para");
	pFunc = PyObject_GetAttrString(pModule, "add");
	pArg = Py_BuildValue("(i,i)", 10, 15); //构造一个元组
	PyEval_CallObject(pFunc, pArg);
	Py_Finalize();
	return 0;
}

#py_test_para.py，带参数
def add(a, b):
    print "a+b=", a+b

opencv中调用python

除了上面调用python脚本的方法，还可以使用c++代码中直接嵌入方式，先附一段嵌入的python代码：

/* embedding Python code */
char *pycode =
"from scipy import signal\n"
"def bwlp(order, f, samplingRate):\n"
"   b, a = signal.butter(order, f/samplingRate, 'low', analog=False)\n"
"   return b, a\n"
"a, b = bwlp(1, f, samplingRate)\n"
"a0 = a[0]\n"
"a1 = a[1]\n"
"b0 = b[0]\n"
"b1 = b[1]\n";

下面使用上面的python代码：

double low_a[2], low_b[2], high_a[2], high_b[2];
// call python butter func
PyObject *main_module, *main_dict;
PyObject *b0_obj, *b1_obj, *a0_obj, *a1_obj, *f_obj, *samplerate_obj;
Py_Initialize();
 // 检查初始化是否成功  
if ( !Py_IsInitialized() ) {  
    return -1;  
  }  

/* Setup the __main__ module to use */
main_module = PyImport_ImportModule("__main__");
main_dict = PyModule_GetDict(main_module);

/* C var to Python var */
samplerate_obj = PyInt_FromLong(long(samplingRate));
f_obj = PyFloat_FromDouble(fl);
/* inject var into __main__ */
PyDict_SetItemString(main_dict, "f", f_obj);
PyDict_SetItemString(main_dict, "samplingRate", samplerate_obj);
PyRun_SimpleString(pycode);

/* Extract the resultant var, double a, b */
b0_obj = PyMapping_GetItemString(main_dict, "b0");
a0_obj = PyMapping_GetItemString(main_dict, "a0");
b1_obj = PyMapping_GetItemString(main_dict, "b1");
a1_obj = PyMapping_GetItemString(main_dict, "a1");
low_b[0] = PyFloat_AsDouble(b0_obj);
low_b[1] = PyFloat_AsDouble(b1_obj);
low_a[0] = PyFloat_AsDouble(a0_obj);
low_a[1] = PyFloat_AsDouble(a1_obj);
Py_Finalize();

参考：

http://blog.csdn.net/taiyang1987912/article/details/44779719

https://www.zhihu.com/question/23003213

http://blog.csdn.NET/sunboyiris/article/details/23737915

http://blog.csdn.net/abcjennifer/article/details/49377123