用c扩展python

搞了一晚上终于做了一个demo，也会用distutils做一个包了，不过现在太晚了，先睡觉，明天好好做下笔记;

写一个简单得python c扩展一共就那么几步，

1。 编写c函数

int math_fib(int n){    if (n<=2)        return 1;    return math_fib(n-1) + math_fib(n-2);}

2. 编写一个包装函数

static PyObject*spam_fib(PyObject *self, PyObject *args){    int n, result;    if (!PyArg_ParseTuple(args, "i", &n))        return NULL;    result = math_fib(n);    return Py_BuildValue("i", result);}

3. 模块函数数组

static PyMethodDef SpamMethods[] = {    {"system", spam_system, METH_VARARGS, "exec a shell command"},    {"fib",    spam_fib,    METH_VARARGS, "cal fibonacci number"},    {NULL, NULL, 0, NULL}};

4. 模块初始化函数

PyMODINIT_FUNCinitspam(void){    PyObject *m;    m = Py_InitModule("spam", SpamMethods);    if (m==NULL)        return;    SpamError = PyErr_NewException("spam.error", NULL, NULL);    Py_INCREF(SpamError);    PyModule_AddObject(m, "error", SpamError);}

这样c扩展就写好了，现在是将其编译成动态连接库，python提供了一个很好得工具distutils, 就不需要自己写makefile 手动编译了

5.编写setup.py

from distutils.core import setup, Extensionmodule1 = Extension('spam',                    sources = ['spammodule.c'])setup (name = 'spam',       version = '1.0',       description = 'this is a demo package',       ext_modules = [module1],       author = 'Arthur')

6. python setup.py build #编译

    python setup.py install #安装

    python setup.py sdist #将源码打包