linux平台上面python调用c

不能免俗，先打印个helloworld出来，c代码的函数

hello.c

#include <stdio.h>
int helloworld()
{
    printf("hello world!");
    return 0;
}

然后编译成动态链接库

 gcc hello.c -fPIC -shared -o libhello.so  

最后在python中引入ctypes这个包，然后通过一个对dlopen包装的CDLL就可以引用so中的代码

 import ctypes
 so=ctypes.CDLL("./libhello.so")
 so.helloworld()

python3和python都能够执行

python3 main.py                          
 hello world!

python main.py  
hello world!

python仅仅支持c代码的这种方式，如果使用c++的编译器，则会报错，例如仅仅是把文件名称替换为hello.cpp

gcc hello.cpp -fPIC -shared -o libhello.so

此时再执行

python ./main.py  

则出现这种错误

Traceback (most recent call last):
  File "./main.py", line 15, in <module>
    so=ctypes.CDLL("./libhello.so")
  File "/usr/local/lib/python2.7/ctypes/__init__.py", line 365, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: ./libhello.so: undefined symbol: __gxx_personality_v0

用g++更错

g++ hello.cpp -fPIC -shared -o libhello.so

则出现

Traceback (most recent call last):
  File "./main.py", line 16, in <module>
    so.helloworld()
  File "/usr/local/lib/python2.7/ctypes/__init__.py", line 378, in __getattr__
    func = self.__getitem__(name)
  File "/usr/local/lib/python2.7/ctypes/__init__.py", line 383, in __getitem__
    func = self._FuncPtr((name_or_ordinal, self))
AttributeError: ./libhello.so: undefined symbol: helloworld