cython_test.sh

root@arch area: # 首先输出c版本
root@arch area: cat area.h 
#ifndef _AREA_H
#define _AREA_H

struct Square {
    float length;
    float width;
};

typedef struct Square *pSquare;

float calc_area(pSquare);

#endif /* area.h */
root@arch area: cat area.c 
#include <stdio.h>
#include <stdlib.h>

#include "area.h"


float calc_area(pSquare s) {
    return s->length * s->width;
}

int main(void) {
    pSquare s = (pSquare)malloc(sizeof(struct Square));
    if (s == NULL) {
        printf("memory not enough");
        exit(1);
    }
    s->length = 10.0;
    s->width = 3.0;
    printf("area of the square: %f\n", calc_area(s));
    free(s);
}
root@arch area: # 运行一下
root@arch area: cc area.c && ./a.out && rm a.out
area of the square: 30.000000
root@arch area: # 为area.c定义包裹的Cython头文件
root@arch area: cat carea.pxd 
cdef extern from "area.h":
    cdef struct Square:
        float length
        float width

    ctypedef Square *pSquare;

    cdef float calc_area(pSquare);
root@arch area: # 为python版本Square定义Cython头文件
root@arch area: cat py_area.pxd 
cimport carea

cdef class Square:
    cdef carea.pSquare _square

    cpdef float calc_area(Square)
root@arch area: # 为python版本Square包裹一下
root@arch area: cat py_area.pyx 
from cpython.mem cimport PyMem_Malloc, PyMem_Free

cimport carea

cdef class Square:
    def __cinit__(self, length, width):
        self._square = <carea.pSquare>PyMem_Malloc(sizeof(carea.Square))
        if not self._square:
            raise MemoryError("Memory not enough")

        self._square.length = length
        self._square.width = width

    def __dealloc__(self):
        PyMem_Free(self._square)

    cpdef float calc_area(self):
        return carea.calc_area(self._square)
root@arch area: # 调用一下
root@arch area: # 哦不，先写好setup.py，然后编译
root@arch area: cat setup.py 
from distutils.core import setup
from distutils.extension import Extension
from Cython.Build import cythonize

ext_modules = cythonize([
    Extension("py_area", ["py_area.pyx", "area.c"])
])

setup(ext_modules=ext_modules)
root@arch area: python3 setup.py build_ext --inplace
running build_ext
building 'py_area' extension
gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fPIC -I/usr/include/python3.6m -c py_area.c -o build/temp.linux-x86_64-3.6/py_area.o
gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fPIC -I/usr/include/python3.6m -c area.c -o build/temp.linux-x86_64-3.6/area.o
gcc -pthread -shared -Wl,-O1,--sort-common,--as-needed,-z,relro -Wl,-O1,--sort-common,--as-needed,-z,relro build/temp.linux-x86_64-3.6/py_area.o build/temp.linux-x86_64-3.6/area.o -L/usr/lib -lpython3.6m -o /root/tests/area/py_area.cpython-36m-x86_64-linux-gnu.so
root@arch area: # 调用
root@arch area: ipython
Python 3.6.0 (default, Dec 24 2016, 08:03:08) 
Type "copyright", "credits" or "license" for more information.

IPython 5.1.0 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: import py_area

In [2]: a = py_area.Square(10, 20)

In [3]: a.calc_area()
Out[3]: 200.0

In [4]:                                                                                                                                
Do you really want to exit ([y]/n)? 

注意Cython版本的实现和“头文件”里的声明类型要保持一致。