[Distutils] Sharing code between C extensions

[Jack Jansen]

On maandag, oktober 21, 2002, at 01:27 , Anders J. Munch wrote:
> What I'd like to do is to have multiple C extensions in the same .pyd.

All attempts to do this lead to disaster. If it isn't on your 
platform it is on another one. And the same is true for multiple 
.pyd files, each containing a single module, that link against 
each other. (I know: been there, done that:-)

There's two solutions I use for this, but you'd have to work out 
the distutils magic for yourself:

1. Use a normal shared library (.dll, .so) for the shared code 
and/or the glue between the modules. Use a shared-data DLL if 
you need to share data. On some OSes you can get away with 
putting the dll in the same directory as the pyd's, on others 
you may have to install it in a system location. PythonWin does 
something like this with PyWinTypes. MacPython does it with a 
little help from the core.

2. Use Python's import mechanism. In module A's init() routine 
import module B. Call a special method in B that returns a 
pointer (coded a Python integer or Cobject or some such). You 
now have a pointer from one module to the other. Numeric does 
this.
--
- Jack Jansen        <Jack.Jansen@oratrix.com>        
http://www.cwi.nl/~jack -
- If I can't dance I don't want to be part of your revolution -- 
Emma Goldman -