python调用c代码

Linux环境下使用python调用C的printf例子：

#!/usr/bin/env python2.7

#-*- coding:utf-8 -*-

from ctypes import *

def test():

    #libc = cdll.LoadLibrary("libc.so.6")

    libc = CDLL("libc.so.6")                                                                                                 
    msg = "hello world!\n"

    libc.printf("Testing:%s",msg)

def main():

    test()

if __name__ == ‘__main__‘:

    main()

python中结构体对应的类型：

#!/usr/bin/env python2.7

#-*- coding:utf-8 -*-

from ctypes import *

class barley_amout(Structure):

    _fields_ = [

        ("barley_long",c_long),

        ("barley_int",c_int),

        ("barley_char",c_char*100)

        ]

def main():

    bu = barley_amout(66,44,"Hello world")

    print bu.barley_long

    print bu.barley_int

    print bu.barley_char

if __name__ == ‘__main__‘:

    main()

python中Union体对应的类型：

class _U(Union):

    _fields_ = [("lptdesc", POINTER(TYPEDESC)),

                ("lpadesc", POINTER(ARRAYDESC)),

                ("hreftype", HREFTYPE)]

class TYPEDESC(Structure):

    _anonymous_ = ("u",)

    _fields_ = [("u", _U),

                ("vt", VARTYPE)]

调用方式

td = TYPEDESC()

td.vt = VT_PTR

td.lptdesc = POINTER(some_type)

td.u.lptdesc = POINTER(some_type)

生成单个so动态库并通过python调用

1、test.c文件

#include <stdio.h>

void print_helloworld(){

    printf("%s","Hello world!\n");

}
int main(){

    print_helloworld();

    return 0;

}

2、生成动态库文件

gcc -fPIC -c test.c  -o libtest.o

通过这种方式在python调用的时候出现

OSError: ./libtest.o: only ET_DYN and ET_EXEC can be loaded

参照这个博客http://xieruilin.iteye.com/blog/730422

修改方式如下：

gcc -fpic -shared -o libtest.o ./test.c 

3、python调用

[[email protected] 20140509]# more call_test.py

#!/usr/bin/env python2.7

#-*- coding:utf-8 -*-

from ctypes import *

def test():

    libc = CDLL("./libtest.o")

    libc.print_helloworld()
if __name__ == ‘__main__‘:

    test()

[[email protected] 20140509]# ./call_test.py

Hello world!

 参考文献

https://docs.python.org/2/library/ctypes.html?highlight=structure#ctypes.Structure

https://docs.python.org/2.7/library/ctypes.html#module-ctypes

http://wangrqa.blog.163.com/blog/static/170946827201010309510247/

http://csl.name/C-functions-from-Python/

http://mypyg.iteye.com/blog/845915

python调用c代码,布布扣,bubuko.com