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>del
8
The ulNum is : 100
The ulNum is : 99
The ulNum is : 98
...........
The ulNum is : 2
The ulNum is : 1
Use 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!