Step by step to write Python extensions in C language

This article describes how to extend Python with the C language. As an example, add a function for Python to set the string to the Windows clipboard (Clipboard). I was writing ...

This article describes how to extend Python with the C language. As an example, add a function for Python to set the string to the Windows clipboard (Clipboard). The environment I used to write the following code is: Windows XP, Gcc.exe 4.7.2, Python 3.2.3.

The first step is to compose the C language DLL

Create a clip.c file that reads as follows:

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// 设置 UNICODE 库，这样的话才可以正确复制宽字符集#define UNICODE  #include <windows.h>#include <python.h> // 设置文本到剪切板(Clipboard)staticPyObject *setclip(PyObject *self, PyObject *args){  LPTSTRlptstrCopy;  HGLOBALhglbCopy;  Py_UNICODE *content;  intlen = 0;   // 将 python 的 UNICODE 字符串及长度传入  if(!PyArg_ParseTuple(args, "u#", &content, &len))    returnNULL;   Py_INCREF(Py_None);   if(!OpenClipboard(NULL))    returnPy_None;   EmptyClipboard();   hglbCopy = GlobalAlloc(GMEM_MOVEABLE, (len+1) * sizeof(Py_UNICODE));  if(hglbCopy == NULL) {    CloseClipboard();    returnPy_None;  }   lptstrCopy = GlobalLock(hglbCopy);  memcpy(lptstrCopy, content, len * sizeof(Py_UNICODE));  lptstrCopy[len] = (Py_UNICODE) 0;   GlobalUnlock(hglbCopy);   SetClipboardData(CF_UNICODETEXT, hglbCopy);    CloseClipboard();   returnPy_None;} // 定义导出给 python 的方法staticPyMethodDef ClipMethods[] = {  {"setclip", setclip, METH_VARARGS,   "Set string to clip."},  {NULL, NULL, 0, NULL}}; // 定义 python 的 modelstaticstructPyModuleDef clipmodule = {  PyModuleDef_HEAD_INIT,  "clip",  NULL,  -1,  ClipMethods}; // 初始化 python modelPyMODINIT_FUNC PyInit_clip(void){  returnPyModule_Create(&clipmodule);}

The second step is to write the Python setup.py

Create a setup.py file that reads as follows:

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fromdistutils.core importsetup, Extension module1 =Extension(‘clip‘,                    sources =[‘clip.c‘]) setup (name =‘clip‘,       version =‘1.0‘,       description =‘This is a clip package‘,       ext_modules =[module1])

The third step is to compile with Python

Run the following command:

Python setup.py build--compiler=mingw32 Install

The following error is prompted in my environment:

gcc:error:unrecognized command line option '-mno-cygwin '

Error:command ' gcc ' failed with exit status 1

Open the%python installation directory%/lib/distutils/cygwinccompiler.py file, delete the-mno-cygwin inside, and then run it again.

After normal operation, a Clip.pyd file is generated and the file is copied to the%python installation directory%/lib/site-packages directory

The fourth step tests the extension

Write a test.py that reads as follows:

123	# -*- encoding: gbk -*-importclipclip.setclip("Hello python")

Run

Python test.py

Paste it anywhere else to verify that it is correct.

Step by step to write Python extensions in C language