python - 编程语言如何调用用另一种语言编写的代码？

Question

抱歉，如果这太含糊了。我最近在阅读 python 的 list.sort() 方法，并了解到它是出于性能原因用 C 语言编写的。

我假设 python 代码只是将一个列表传递给 C 代码，C 代码将一个列表传回，但是 python 代码如何知道将它传递到哪里或者 C 给它正确的数据类型，并且C 代码如何知道给定的数据类型？

Answer 1

Python 可以在 C/C++ 中扩展(更多信息 here)

这基本上意味着您可以像这样包装一个 C 模块

#include "Python.h"

// Static function returning a PyObject pointer
static PyObject *
keywdarg_parrot(PyObject *self, PyObject *args, PyObject *keywds) 
// takes self, args and kwargs.
{ 
    int voltage;
    // No such thing as strings here. Its a tough life.
    char *state = "a stiff";
    char *action = "voom";
    char *type = "Norwegian Blue";
    // Possible keywords
    static char *kwlist[] = {"voltage", "state", "action", "type", NULL};

    // unpack arguments
    if (!PyArg_ParseTupleAndKeywords(args, keywds, "i|sss", kwlist,
                                     &voltage, &state, &action, &type))
        return NULL;
    // print to stdout
    printf("-- This parrot wouldn't %s if you put %i Volts through it.\n",
           action, voltage);
    printf("-- Lovely plumage, the %s -- It's %s!\n", type, state);

    // Reference count some None.
    Py_INCREF(Py_None);
    // return some none.
    return Py_None;
}
// Static PyMethodDef
static PyMethodDef keywdarg_methods[] = {
    /* The cast of the function is necessary since PyCFunction values
     * only take two PyObject* parameters, and keywdarg_parrot() takes
     * three.
     */
    // Declare the parrot function, say what it takes and give it a doc string.
    {"parrot", (PyCFunction)keywdarg_parrot, METH_VARARGS | METH_KEYWORDS,
     "Print a lovely skit to standard output."},
    {NULL, NULL, 0, NULL}   /* sentinel */
};

并且使用 Python 头文件，它将定义和理解 C/C++ 代码中的入口点和返回位置。