python from-import语句用法

testpy.py

#!/usr/bin/env python
 

def euclid(a, b):
    while b:
        a, b = b, a%b
    return a

$ python

Python 2.7.6 (default, Jun 22 2015, 17:58:13) 

[GCC 4.8.2] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>>> from testpy import euclid

>>> euclid(100,30)

10

>>> euclid(120,30)

30

>>> euclid(120,48)

24

>>>

测试mytest.py

#!/usr/bin/env python
from testpy import euclid

num1= input("Please enter the first integer: ")
num2= input("Please enter the second integer: ")

print "The Greatest Common Divisor (GCD) is: ", euclid(num1,num2)

$ chmod +x mytest.py

$ ./mytest.py

Please enter the first integer: 120

Please enter the second integer: 48

The Greatest Common Divisor (GCD) is:  24

在c语言中调用python模块中函数

/**
 * @file euclidpy.c
 * gcc -Wall -O2 -o euclidpy euclidpy.c -I/usr/include/python2.7 -L/usr/lib -lpython2.7 -Wl,-R/usr/local/lib
 */
#include <Python.h>
#include <stdio.h>
int main()
{
    //初始化python
    Py_Initialize();
    if (!Py_IsInitialized()) {
        printf("Python_Initialize failed\n");
        return 1;
    }   

    PyObject *pModule = NULL;
    PyObject *pFunc   = NULL;
    PyObject *pArg    = NULL;
    PyObject *result  = NULL;

    PyRun_SimpleString("import sys");                                   //直接执行python语句
    PyRun_SimpleString("import sys;sys.path.append('.')");

    pModule = PyImport_ImportModule("testpy");
    if (pModule == NULL) {
        printf("import module failed!\n");
        return -1;
    }  
    pFunc   = PyObject_GetAttrString(pModule, "euclid");
    pArg    = Py_BuildValue("(i, i)", 120, 48);

    //调用函数，并得到python类型的返回值
    result =PyEval_CallObject(pFunc,pArg);

    //c用来保存c/c++类型的返回值
    int c;
    //将python类型的返回值转换为c/c++类型
    PyArg_Parse(result, "i", &c);
    //输出返回值
    printf("The Greatest Common Divisor (GCD) is:%d\n", c);
    
    Py_Finalize();
    return 0;
}

编译和运行：

$ gcc -Wall -O2 -o euclidpy euclidpy.c -I/usr/include/python2.7 -L/usr/lib -lpython2.7 -Wl,-R/usr/local/lib

$ ./euclidpy 

The Greatest Common Divisor (GCD) is:24