Question

我在代码中将C扩展名作为子模块时遇到了困难。下面的C扩展编译得很好。当我尝试将其添加到另一个模块时会出现问题。

这是C代码：文件名是prctl3-0.c。我能够为Python2.7和Python 3.0编译它。

#include <Python.h>

#include <stdio.h>
#include <string.h>
#include <sys/prctl.h>

// Now we need to identify which version of Python we are working with.
//  For backwards compatibility, we need to be able to be compiled by either
//  Python 2.7 or Python3.x.

#if PY_MAJOR_VERSION >=3
#define PY_3CODE            // We will use this pre-compile statement to differentiate
                            //  between code for Py2.7 and 3.x
#endif

/* osCall_changeName
  Calls prctl() to change the name of the calling thread, process or subprocess

*/
static PyObject* osCall_changeName(PyObject*self, PyObject* args)
{
  const char *passedInName;   // Name passed in by the system
  size_t nameLength;          // Calculated by calling strlen() on passedInName

  char newName[16];           // In Python newName= passedInName[0:15]+ \0
  int nameChangeRes;          // stores error code for calling prctl()

  PyObject *retName;          // Return value; Python None if error occurs

  // Check if argument passed in successfully
  if(! PyArg_ParseTuple(args, "s", &passedInName)){
    printf("Error in arg passing\n");
    Py_RETURN_NONE;
  }

  nameLength = strlen(passedInName);
  if( nameLength > 15){       // prctl() automatically truncates, but unsure if new string is null-terminated
     strncpy(newName, passedInName, 15);
     newName[15] = '\0';
  } else {
    strcpy(newName, passedInName);
  }

  //Actual function call
  nameChangeRes = prctl(PR_SET_NAME, newName, 0,0,0);

  if( nameChangeRes == 0 )    // Success; pass back the changed name value
  {
    retName = Py_BuildValue("s", newName);
    return retName;
  }

  // Method failed; return None
  Py_RETURN_NONE;
}

static PyObject* osCall_getName(PyObject* self) {

  char procName[16];          // Buffer to put prctl results into
  int  nameRetrieveRes;       // Result of the name retrieval operation
  PyObject *retName;          // Python object to return values


  nameRetrieveRes = prctl(PR_GET_NAME, procName, 0,0,0);

  if ( nameRetrieveRes == 0 ) //
  {
      retName = Py_BuildValue("s", procName);
      return retName;
  }
  printf("Process name change failed\n");
  // Operation failed; return None
  Py_RETURN_NONE;
}

//==========================================================
//  STEP 2: COMPILE THE PIECES NEEDED FOR EITHER 2.7 OR 3.X
//    PYTHON LIBRARIES
//==========================================================

static PyMethodDef proc_OsFunc[] = {
  { "changeName",
  (PyCFunction)osCall_changeName,
  METH_VARARGS,
  "Function to give Python process a new associated string ID"},

  { "getName",
  (PyCFunction)osCall_getName,
  METH_NOARGS,
  "Function to get Python process's current string ID"
  },

  {NULL, NULL, 0, NULL} //function array terminator
};

#ifdef PY_3CODE
static struct PyModuleDef osCallDefine = {
  PyModuleDef_HEAD_INIT,
  "prctl3_0",
  "A simple library for accessing prctl() on Linux from Python 3.0",
  -1,
  proc_OsFunc
};

#endif

#ifdef PY_3CODE
// Python 3.0 initialization syntax
PyMODINIT_FUNC PyInit_prctl3_0(void)
{
  Py_Initialize();

  return PyModule_Create(&osCallDefine);
}

#else
// Python 2.0 initialization syntax
PyMODINIT_FUNC initprctl3_0() {
  Py_InitModule3("prctl3_0",proc_OsFunc,
        "A simple library for accessing prctl() on Linux from Python 2.0");
}



#endif

我希望将此代码作为更大项目的一部分放在模块名mpIPC中。我遇到的问题是当我把它放入一个更大的模块，并尝试使用以下代码访问它时，我得到以下内容：

>>> import mpIPC.prctl3_0
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named prctl3_0

我的setup.py文件如下：

from setuptools import setup, find_packages, Extension

prctl_module = Extension("mpIPC.prctl3_0",
                                sources = ["mpIPC/prctl3_0.c"])

setup(name = "mpIPC",
    version = '0.0',
    description = "Python C module for accessing Linux commands for IPC",
    packages = ['mpIPC'],
    ext_modules = [prctl_module] )

此模块的文件目录：

project/
+- setup.py
+- mkdir/
-+- __init__.py 
-+- prctl3_0.c
-+- os.py   # used for other Linux os calls

我不确定我错过了什么。我还检查了以下链接： How to build a Python C Extension so I can import it from a module 但在这一点上它并没有真正帮助我。

Answer 1

我没有任何源代码修改工作。

您的目录＆＃34; mkdir＆＃34; 必须命名为＆＃34; mpIPC＆＃34;，这是模块名称。您希望您的目录结构看起来像在底部
尝试从您的源目录中进行测试，即不是来自project中的任何地方，因为它会尝试导入，根据Python＆＃39; s模块结构，来自目录＆＃34; mpIPC＆＃34; （你将在1中创建））（此提示的信用额转到this comment in the post you mentioned。相反，请在home-dir的任何位置尝试。例如，假设您先运行python setup.py install ：）

目录树：

foobar
    ├── mpIPC
    │   ├── __init__.py
    │   ├── os.py
    │   └── prctl3_0.c
    └── setup.py

Python C-extension子模块错误：没有名为“x”的模块

1 个答案: