Python嵌入使用C - 段错误

Question

从阅读另一个post，我想embbed一些一些Python代码到C：

的main.c

#include <Python.h> 

int callModuleFunc(int array[], size_t size) { 
    PyObject *mymodule = PyImport_ImportModule("py_function"); 
    PyObject *myfunc = PyObject_GetAttrString(mymodule, "printlist"); 
    PyObject *mylist = PyList_New(size); 
    for (size_t i = 0; i != size; ++i) { 
     PyList_SET_ITEM(mylist, i, PyInt_FromLong(array[i])); 
    } 
    PyObject *arglist = Py_BuildValue("(o)", mylist); 
    PyObject *result = PyObject_CallObject(myfunc, arglist); 
    int retval = (int)PyInt_AsLong(result); 
    Py_DECREF(result); 
    Py_DECREF(arglist); 
    Py_DECREF(mylist); 
    Py_DECREF(myfunc); 
    Py_DECREF(mymodule); 
    return retval; 
} 

int main(int argc, char *argv[]) 
{ 
    int a[] = {1,2,3,4}; 
    callModuleFunc(a, 4); 
    return 0; 
} 

py_function.py

'''py_function.py - Python source designed to ''' 
'''demonstrate the use of python embedding''' 

def printlist(mylist): 
    print mylist 

然后我编译：

gcc main.c -I/usr/include/python2.7 -lpython2.7 

但后来我跑的应用程序，它给了我一个分段错误：

/a.out 
[1] 18890 segmentation fault ./a.out 

有没有办法，我失去了一些东西？

Answer 1

存在一些问题与您的代码：

1. Py_Initialize()不叫。
2. PyImport_ImportModule()未能找到您的python文件，因为在嵌入式Python中，您可以从开始，而不是初始模块，相对于此模块可以进行搜索。解决方法是明确包含当前目录sys.path。
3. "(O)" in Py_BuildValue()应该使用大写'O'。
4. printlist函数应返回一个值（因为这是C代码所期望的）。

这应该工作：

的main.c

#include <Python.h> 

void initPython() 
{ 
    Py_Initialize(); 
    PyObject *sysmodule = PyImport_ImportModule("sys"); 
    PyObject *syspath = PyObject_GetAttrString(sysmodule, "path"); 
    PyList_Append(syspath, PyString_FromString(".")); 
    Py_DECREF(syspath); 
    Py_DECREF(sysmodule); 
} 

int callModuleFunc(int array[], size_t size) { 
    PyObject *mymodule = PyImport_ImportModule("py_function"); 
    assert(mymodule != NULL); 
    PyObject *myfunc = PyObject_GetAttrString(mymodule, "printlist"); 
    assert(myfunc != NULL); 
    PyObject *mylist = PyList_New(size); 
    for (size_t i = 0; i != size; ++i) { 
     PyList_SET_ITEM(mylist, i, PyInt_FromLong(array[i])); 
    } 
    PyObject *arglist = Py_BuildValue("(O)", mylist); 
    assert(arglist != NULL); 
    PyObject *result = PyObject_CallObject(myfunc, arglist); 
    assert(result != NULL); 
    int retval = (int)PyInt_AsLong(result); 
    Py_DECREF(result); 
    Py_DECREF(arglist); 
    Py_DECREF(mylist); 
    Py_DECREF(myfunc); 
    Py_DECREF(mymodule); 
    return retval; 
} 

int main(int argc, char *argv[]) 
{ 
    initPython(); 

    int a[] = {1,2,3,4,5,6,7}; 
    callModuleFunc(a, 4); 
    callModuleFunc(a+2, 5); 

    Py_Finalize(); 
    return 0; 
} 

py_function.py

'''py_function.py - Python source designed to ''' 
'''demonstrate the use of python embedding''' 

def printlist(mylist): 
    print mylist 
    return 0