[Baypiggies] Help with ctypes

[Glen Jarvis]

I'm trying to learn how to write my own C-libraries and wrap with  
Python. My first stab at this was with ctypes - it looked cleaner for  
what I wanted to do. I admit, however, I don't understand the error  
that I seem to be getting on several tested platforms.

(Note: Here's the basic documentation: http://docs.python.org/library/ctypes.html)


Here is my very powerful and sophisticated C-library :)  (demo.c):

int demo() {
     return 5;
}

Compile to library (I imagine this is where I am missing a step):
gjarvis at boxee:~$ gcc -c demo.c


And, now I have a spanking good demo.o file:

gjarvis at boxee:~$ file demo.o
demo.o: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not  
stripped



Now, when trying to access with ctypes, I keep seeing the message  
"Only ET_DYN and ET_EXEC can be loaded" -- I'm not able to find any  
web pages or docs to point me in the right direction. Is there  
anything that I'm missing? Do I need to include <Python.h> if it's  
just a one-way-wrap like this? Any direction to documentation -- or a  
very small code snippet to get me started is all I think I'll need:

Python 2.6.2 (release26-maint, Apr 19 2009, 01:56:41)
[GCC 4.3.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
 >>> import ctypes
 >>> demo = ctypes.cdll.LoadLibrary('/home/gjarvis/demo.o')
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
   File "/usr/lib/python2.6/ctypes/__init__.py", line 431, in  
LoadLibrary
     return self._dlltype(name)
   File "/usr/lib/python2.6/ctypes/__init__.py", line 353, in __init__
     self._handle = _dlopen(self._name, mode)
OSError: /home/gjarvis/demo.o: only ET_DYN and ET_EXEC can be loaded


Thanks in Advance,



Glen
--
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