#!/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()

#!/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()

class _U(Union):
    _fields_ = [("lptdesc", POINTER(TYPEDESC)),
                ("lpadesc", POINTER(ARRAYDESC)),
                ("hreftype", HREFTYPE)]

class TYPEDESC(Structure):
    _anonymous_ = ("u",)
    _fields_ = [("u", _U),
                ("vt", VARTYPE)]

td = TYPEDESC()
td.vt = VT_PTR
td.lptdesc = POINTER(some_type)
td.u.lptdesc = POINTER(some_type)

#include <stdio.h>

void print_helloworld(){
    printf("%s","Hello world!\n");
}

int main(){
    print_helloworld();
    return 0;
}

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

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

[root@typhoeus79 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()
[root@typhoeus79 20140509]# ./call_test.py    
Hello world!