Python调用C/C++的种种方法

 Python调用C/C++的种种方法 Python是解释性语言, 底层就是用c实现的, 因此用python调用C是很容易的, 下面就总结一下各类调用的方法, 给出例子, 全部例子都在ubuntu9.10, python2.6下试过.   1. Python 调用 C (base) 想在python中调用c函数, 如这儿的fact #include <Python.h> int fact(int n) {   if (n <= 1)     return 1;   else     return n * fact(n - 1); } PyObject* wrap_fact(PyObject* self, PyObject* args) {   int n, result;   if (! PyArg_ParseTuple(args, "i:fact", &n))     return NULL;   result = fact(n);   return Py_BuildValue("i", result); } static PyMethodDef exampleMethods[] = {   {"fact", wrap_fact, METH_VARARGS, "Caculate N!"},   {NULL, NULL} }; void initexample() {   PyObject* m;   m = Py_InitModule("example", exampleMethods); }   把这段代码存为wrapper.c, 编成so库, gcc -fPIC wrapper.c -o example.so -shared  -I/usr/include/python2.6 -I/usr/lib/python2.6/config   而后在有此so库的目录, 进入python, 能够以下使用 import example example.fact(4)   2. Python 调用 C++ (base) 在python中调用C++类成员函数, 以下调用TestFact类中的fact函数, #include <Python.h> class TestFact{     public:     TestFact(){};     ~TestFact(){};     int fact(int n); }; int TestFact::fact(int n) {   if (n <= 1)     return 1;   else     return n * (n - 1); } int fact(int n) {     TestFact t;     return t.fact(n); } PyObject* wrap_fact(PyObject* self, PyObject* args) {   int n, result;   if (! PyArg_ParseTuple(args, "i:fact", &n))     return NULL;   result = fact(n);   return Py_BuildValue("i", result); } static PyMethodDef exampleMethods[] = {   {"fact", wrap_fact, METH_VARARGS, "Caculate N!"},   {NULL, NULL} }; extern "C"              //不加会致使找不到initexample void initexample() {   PyObject* m;   m = Py_InitModule("example", exampleMethods); }   把这段代码存为wrapper.cpp, 编成so库, g++ -fPIC wrapper.cpp -o example.so -shared -I/usr/include/python2.6 -I/usr/lib/python2.6/config   而后在有此so库的目录, 进入python, 能够以下使用 import example example.fact(4)   3. Python 调用 C++ (Boost.Python) Boost库是很是强大的库, 其中的python库能够用来封装c++被python调用, 功能比较强大, 不但能够封装函数还能封装类, 类成员. http://dev.gameres.com/Program/Abstract/Building%20Hybrid%20Systems%20with%20Boost_Python.CHN.by.JERRY.htm 首先在ubuntu下安装boost.python, apt-get install libboost-python-dev #include <boost/python.hpp> char const* greet() {    return "hello, world"; } BOOST_PYTHON_MODULE(hello) {     using namespace boost::python;     def("greet", greet); } 把代码存为hello.cpp, 编译成so库 g++ hello.cpp -o hello.so -shared -I/usr/include/python2.5 -I/usr/lib/python2.5/config -lboost_python-gcc42-mt-1_34_1   此处python路径设为你的python路径, 而且必须加-lboost_python-gcc42-mt-1_34_1, 这个库名不必定是这个, 去/user/lib查   而后在有此so库的目录, 进入python, 能够以下使用 >>> import hello >>> hello.greet() 'hello, world'   4. python 调用 c++ (ctypes) ctypes is an advanced ffi (Foreign Function Interface) package for Python 2.3 and higher. In Python 2.5 it is already included. ctypes allows to call functions in dlls/shared libraries and has extensive facilities to create, access and manipulate simple and complicated C data types in Python - in other words: wrap libraries in pure Python. It is even possible to implement C callback functions in pure Python. http://python.net/crew/theller/ctypes/   #include <Python.h> class TestFact{     public:     TestFact(){};     ~TestFact(){};     int fact(int n); }; int TestFact::fact(int n) {   if (n <= 1)     return 1;   else     return n * (n - 1); } extern "C" int fact(int n) {     TestFact t;     return t.fact(n); } 将代码存为wrapper.cpp不用写python接口封装, 直接编译成so库, g++ -fPIC wrapper.cpp -o example.so -shared -I/usr/include/python2.6 -I/usr/lib/python2.6/config   进入python, 能够以下使用 >>> import ctypes >>> pdll = ctypes.CDLL('/home/ubuntu/tmp/example.so') >>> pdll.fact(4) 12