python中调用C++写的动态库

一、环境：Windows XP + Python3.2

1. dll对应的源文件(m.cpp)：

#include <stdio.h>extern "C"{_declspec(dllexport) int add(int a, int b){return a+b;}_declspec(dllexport) void print_sum(unsigned long ulNum){while(ulNum != 0){printf("The ulNum is : %u\n", ulNum--);}}}

2. python源程序：

# coding=GBKfrom ctypes import *import timeif __name__ == '__main__':time_begin = time.clock()#dll = CDLL("d.dll")# 加载dll方式一dll = cdll.LoadLibrary("d.dll")# 加载dll方式二print(dll.add(2, 6))# 调用dll中add方法dll.print_sum(100)# 调用dll中print_sum方法t = time.clock() - time_begin# 计算时间差print("Use time: %f" %t)# 打印耗时时间

运行输出：

E:\Program\Python>del8The ulNum is : 100The ulNum is : 99The ulNum is : 98...........The ulNum is : 2The ulNum is : 1Use time: 0.003853E:\Program\Python>

二、环境：Fedora12 + Python2.6

1. 动态库源文件(a.cpp):

#include <stdio.h>extern "C"{int add(int a, int b){return a+b;}void print_sum(unsigned long ulNum){while(ulNum != 0){printf("The ulNum is : %u\n", ulNum--);}}}

编译指令：g++ -shared -o liba.so a.cpp

2. python源程序(del.py)：

#!/usr/bin/env python# coding=UTF-8from ctypes import *import timeif __name__ == '__main__':time_begin = time.clock()dll = CDLL("./liba.so")# 加载dll方式一(默认在系统lib库路径下查找.so文件)#dll = cdll.LoadLibrary("./liba.so")# 加载dll方式二print(dll.add(2, 6))# 调用dll中add方法dll.print_sum(10000)# 调用dll中print_sum方法t = time.clock() - time_begin# 计算时间差print("\nUse time: %s" %t)# 打印耗时时间

运行结果：与windows版本基本相同!

结论：Linux上用Python加载动态库时默认是从系统lib路径下是查找库文件的。所以在python中加载当前路径下的动态库的话，路径要写“./liba.so"，否则会提示动态库文件找不到！