用python编译错误gcc。

I am trying to embed python in c++ and I have been playing with some sample code for a while. I was working with boost python interpreter and it works okay but right now I cannot seem to compile some c++ code that uses Python.h. I get an error that seems to be the library is not referenced correctly (this code is supposed to work as it is copied straight off of http://www.codeproject.com/Articles/11805/Embedding-Python-in-C-C-Part-I). I have tried many flags for compiling. Any help will be much appreciated! Thanks :)

我正在尝试在c++中嵌入python，并且我一直在玩一些示例代码。我正在使用boost python解释器，它运行良好，但是现在我似乎不能编译使用python的c++代码。我有一个错误，似乎是库没有被正确引用(这段代码应该是工作的，因为它是直接从http://www.codeproject.com/articles/11805/嵌入- python - c - parti)。我尝试了许多标记来编译。非常感谢您的帮助!谢谢:)

Below is the one example and the error I received:

下面是我收到的一个例子和错误:

g++ -Wall -o call_function call_function.c

g++ -Wall -o call_function call_function.c。

call_function.c: In function âint main(int, char**)â:
call_function.c:61:56: warning: format â%dâ expects argument of type âintâ, but argument 2 has type âlong intâ [-Wformat]
/tmp/ccAUMMHm.o: In function `main':
call_function.c:(.text+0x2a): undefined reference to `Py_Initialize'
call_function.c:(.text+0x3d): undefined reference to `PyString_FromString'
call_function.c:(.text+0x4d): undefined reference to `PyImport_Import'
call_function.c:(.text+0x5d): undefined reference to `PyModule_GetDict'
call_function.c:(.text+0x7b): undefined reference to `PyDict_GetItemString'
call_function.c:(.text+0x8b): undefined reference to `PyCallable_Check'
call_function.c:(.text+0xb2): undefined reference to `PyTuple_New'
call_function.c:(.text+0xe5): undefined reference to `PyInt_FromLong'
call_function.c:(.text+0xf5): undefined reference to `PyErr_Print'
call_function.c:(.text+0x118): undefined reference to `PyTuple_SetItem'
call_function.c:(.text+0x13f): undefined reference to `PyObject_CallObject'
call_function.c:(.text+0x195): undefined reference to `PyObject_CallObject'
call_function.c:(.text+0x1ac): undefined reference to `PyInt_AsLong'
call_function.c:(.text+0x1fd): undefined reference to `PyErr_Print'
call_function.c:(.text+0x204): undefined reference to `PyErr_Print'
call_function.c:(.text+0x279): undefined reference to `Py_Finalize'
collect2: ld returned 1 exit status

The following is the c++ code

下面是c++代码。

// call_function.c - A sample of calling python functions from C code
//
#include "/usr/include/python2.6/Python.h"

int main(int argc, char *argv[])
{
    int i;
    PyObject *pName, *pModule, *pDict, *pFunc, *pArgs, *pValue;
    if (argc < 3)
    {
        printf("Usage: exe_name python_source function_name\n");
        return 1;
    }
    // Initialize the Python Interpreter
    Py_Initialize();
    // Build the name object
    pName = PyString_FromString(argv[1]);
    // Load the module object
    pModule = PyImport_Import(pName);
    // pDict is a borrowed reference
    pDict = PyModule_GetDict(pModule);
    // pFunc is also a borrowed reference
    pFunc = PyDict_GetItemString(pDict, argv[2]);
    if (PyCallable_Check(pFunc))
    {
        // Prepare the argument list for the call
        if( argc > 3 )
        {
                pArgs = PyTuple_New(argc - 3);
                for (i = 0; i < argc - 3; i++)
                {
                    pValue = PyInt_FromLong(atoi(argv[i + 3]));
                    if (!pValue)
                    {
                        PyErr_Print();
                        return 1;
                    }
                    PyTuple_SetItem(pArgs, i, pValue);
                }
                pValue = PyObject_CallObject(pFunc, pArgs);
                if (pArgs != NULL)
                {
                    Py_DECREF(pArgs);
                }
        } else
        {
                pValue = PyObject_CallObject(pFunc, NULL);
        }
        if (pValue != NULL)
        {
            printf("Return of call : %d\n", PyInt_AsLong(pValue));
            Py_DECREF(pValue);
        }
        else
        {
            PyErr_Print();
        }
    } else
    {
        PyErr_Print();
    }

    // Clean up
    Py_DECREF(pModule);
    Py_DECREF(pName);
    // Finish the Python Interpreter
    Py_Finalize();
    return 0;
}

The following is the python script:

下面是python脚本:

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

def multiply():
    c = 12345*6789
    print 'The result of 12345 x 6789 :', c
    return c

1 个解决方案

#1

You need to compile with -lpython2.6.

您需要用-lpython2.6编译。

The compiler is unable to find the python functions, which are defined in libpythonX.Y.so. To tell it to use that library, you need to add -lpythonX.Y. As your Python version is 2.6, you need to use -lpython2.6.

编译器无法找到在libpythonxt中定义的python函数。要告诉它使用那个库，您需要添加-lpythonX.Y。由于您的Python版本是2.6，您需要使用-lpython2.6。

The fact that you're getting things like (.text+0xf00) tells you that this is a linker problem, which means that your code itself is fine. The problem is just that some functions are not fully defined. This means, the compiler knew the prototype (that is, return type and argument values) while compiling (from the header), but it doesn't know where the actual code is. It is up to the linker to figure that out, and it cannot know by magic where it'll find the neccessary functions.

事实上，您得到的是(.text+0xf00)这样的东西，它告诉您这是一个链接器问题，这意味着您的代码本身很好。问题是有些函数没有完全定义。这意味着，编译器在编译(从标题)时知道原型(即返回类型和参数值)，但是它不知道实际代码在哪里。它是由链接器来计算出来的，它不可能通过魔法知道它会在哪里找到必要的函数。