Question

我想创建一个嵌入式python 3解释器，让python脚本导入通过C Python API创建的模块。

创建＆＃34;顶级＆＃34;没问题模块，但现在我想用软件包组织我的模块......但是我失败了。

这是我目前的（简单）代码：

#include <Python.h>

//// Definition of 'emb.sub' module
static PyObject* emb_sub_foo(PyObject *self, PyObject *args)
{
    char const* n = "I am sub foo";
    return Py_BuildValue("s", n);
}
static PyMethodDef EmbSubMethods[] = {
    {"foo", emb_sub_foo, METH_VARARGS, "Returns sub foo"},
    {NULL, NULL, 0, NULL}
};
static PyModuleDef EmbSubModule = {
    PyModuleDef_HEAD_INIT, "emb.sub", NULL, -1, EmbSubMethods,
    NULL, NULL, NULL, NULL
};
static PyObject* PyInit_emb_sub(void)
{
    return PyModule_Create(&EmbSubModule);
}

//// Embedded Python
int main()
{
    PyImport_AppendInittab("emb.emb", &PyInit_emb_sub);
    Py_Initialize();

    PyRun_SimpleString("import emb.sub\n");

    Py_Finalize();
    return 0;
}

当我执行程序时，我得到：

Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named 'emb'

所以我创建了一个空的emb模块，并将其__path__设置为：

#include <Python.h>

//// Definition of 'emb' module
static PyModuleDef EmbModule = {
    PyModuleDef_HEAD_INIT, "emb", NULL, -1, NULL,
    NULL, NULL, NULL, NULL
};
static PyObject* PyInit_emb(void)
{
    PyObject *mod = PyModule_Create(&EmbModule);
    PyModule_AddObject(mod, "__path__", Py_BuildValue("()"));

    return mod;
}

//// Definition of 'emb.sub' module
static PyObject* emb_sub_foo(PyObject *self, PyObject *args)
{
    char const* n = "I am sub foo";
    return Py_BuildValue("s", n);
}
static PyMethodDef EmbSubMethods[] = {
    {"foo", emb_sub_foo, METH_VARARGS, "Returns sub foo"},
    {NULL, NULL, 0, NULL}
};
static PyModuleDef EmbSubModule = {
    PyModuleDef_HEAD_INIT, "emb.sub", NULL, -1, EmbSubMethods,
    NULL, NULL, NULL, NULL
};
static PyObject* PyInit_emb_sub(void)
{
    return PyModule_Create(&EmbSubModule);
}

//// Embedded Python
int main()
{
    PyImport_AppendInittab("emb", &PyInit_emb);
    PyImport_AppendInittab("emb.sub", &PyInit_emb_sub);
    Py_Initialize();

    PyRun_SimpleString("import emb.sub\n");

    Py_Finalize();
    return 0;
}

现在我收到了这个错误：

Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named 'emb.sub'

我想知道是否可以在嵌入式python中创建包和模块的层次结构？

谢谢！

Answer 1

据我所知，默认的内置模块处理无法与包+模块名称匹配。这可以通过添加一个自定义导入钩子来解决，只需在Py_Initialize（）之后运行它：

PyRun_SimpleString(
    "import importlib.abc\n" \
    "import importlib.machinery\n" \
    "import sys\n" \
    "\n" \
    "\n" \
    "class Finder(importlib.abc.MetaPathFinder):\n" \
    "    def find_spec(self, fullname, path, target=None):\n" \
    "        if fullname in sys.builtin_module_names:\n" \
    "            return importlib.machinery.ModuleSpec(\n" \
    "                fullname,\n" \
    "                importlib.machinery.BuiltinImporter,\n" \
    "            )\n" \
    "\n" \
    "\n" \
    "sys.meta_path.append(Finder())\n" \
);

我用完整的代码尝试了这一点并取得了成功：

#include <Python.h>

//// Definition of 'emb' module
static PyModuleDef EmbModule = {
    PyModuleDef_HEAD_INIT, "emb", NULL, -1, NULL,
    NULL, NULL, NULL, NULL
};
static PyObject* PyInit_emb(void)
{
    PyObject *mod = PyModule_Create(&EmbModule);
    PyModule_AddObject(mod, "__path__", Py_BuildValue("()"));

    return mod;
}

//// Definition of 'emb.sub' module
static PyObject* emb_sub_foo(PyObject *self, PyObject *args)
{
    char const* n = "I am sub foo";
    return Py_BuildValue("s", n);
}
static PyMethodDef EmbSubMethods[] = {
    {"foo", emb_sub_foo, METH_VARARGS, "Returns sub foo"},
    {NULL, NULL, 0, NULL}
};
static PyModuleDef EmbSubModule = {
    PyModuleDef_HEAD_INIT, "emb.sub", NULL, -1, EmbSubMethods,
    NULL, NULL, NULL, NULL
};
static PyObject* PyInit_emb_sub(void)
{
    return PyModule_Create(&EmbSubModule);
}

//// Embedded Python
int main()
{
    PyImport_AppendInittab("emb", &PyInit_emb);
    PyImport_AppendInittab("emb.sub", &PyInit_emb_sub);
    Py_Initialize();

    PyRun_SimpleString(
        "import importlib.abc\n" \
        "import importlib.machinery\n" \
        "import sys\n" \
        "\n" \
        "\n" \
        "class Finder(importlib.abc.MetaPathFinder):\n" \
        "    def find_spec(self, fullname, path, target=None):\n" \
        "        if fullname in sys.builtin_module_names:\n" \
        "            return importlib.machinery.ModuleSpec(\n" \
        "                fullname,\n" \
        "                importlib.machinery.BuiltinImporter,\n" \
        "            )\n" \
        "\n" \
        "\n" \
        "sys.meta_path.append(Finder())\n" \
    );

    PyRun_SimpleString("import emb.sub\n");
    PyRun_SimpleString("print(emb.sub.foo())\n");

    Py_Finalize();
    return 0;
}

以编程方式在嵌入式python 3

1 个答案: