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). 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:

Set up a Unicode library so that the wide character set # # UNICODE #include can be copied correctly
 
  #include
  
   
  Set Text to clipboard (Clipboard) static Pyobject *setclip (Pyobject *self, Pyobject *args) {LPTSTR lptstrcopy;  Hglobal hglbcopy;  Py_unicode *content;    int len = 0; Pass the Python UNICODE string and length to the IF (!    Pyarg_parsetuple (args, "u#", &content, &len)) return NULL;    Py_incref (Py_none); if (!    OpenClipboard (NULL)) return py_none;    EmptyClipboard ();  Hglbcopy = GlobalAlloc (gmem_moveable, (len+1) * sizeof (Py_unicode));    if (hglbcopy = = NULL) {CloseClipboard ();  return py_none;  } lptstrcopy = GlobalLock (hglbcopy);  memcpy (lptstrcopy, content, Len * sizeof (Py_unicode));    Lptstrcopy[len] = (py_unicode) 0;    GlobalUnlock (hglbcopy);    SetClipboardData (Cf_unicodetext, hglbcopy);    CloseClipboard ();  return py_none;} Defines the method that is exported to Python static pymethoddef clipmethods[] = {{"SetClip", SetClip, Meth_varargs, "Set string to clip."}, {NU  LL, NULL, 0, NULL}}; Define Python's modelstatic struct pymoduledef clipmodule = {pymoduledef_head_init, "clip", NULL,-1, CliPmethods}; Initialize Python modelpymodinit_func pyinit_clip (void) {return pymodule_create (&clipmodule);}
  
 

The second step is to write the Python setup.py

Create a setup.py file that reads as follows:

From Distutils.core Import Setup, Extension  module1 = Extension (' clip ',                    sources = [' clip.c '])  setup (name = ' Clip ',       Version = ' 1.0 ',       description = ' This was 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:

#-*-ENCODING:GBK-*-import clipclip.setclip ("Hello python")

Run

Python test.py

Paste it anywhere else to verify that it is correct.

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