Manipulating sys.path

[Thomas]

Hi all,

I want to manipulate sys.path outside of PYTHONPATH (environment) and 
sys.path.append() (programmatically).

A bit of background:
We're maintaining a small application that includes a couple of Python 
scripts. Over time, a decent amount of code has been forked into 
modules, so the overall file system layout of our kit looks like this:

tool/
   bin/
     prog1.py
     prog2.py
     ...
   lib/
     pack1/
       mod1.py
       mod2.py
       ...

The issue I have is that I want to add the 'lib' directory to the module 
search path so that our programs prog1.py, prog2.py,... can find the 
modules pack1.mod1, pack1.mod2, ... But I want to keep this out of the 
program's source code which rules out statements like 
'sys.path.insert(0, "../lib")'. We also want to be minimal-invasive for 
the hosting environment, so no copying of 'lib' into the standard Python 
lib directories (like /usr/local/lib/python2.5/site-packages etc.), nor 
forcing the user to change his PYTHONPATH shell environment. It should 
be solved locally in our kit's directory tree.

I was thinking about putting code into a 'bin/__init__.py' file but 
that's only working for modules and not for executable scripts, right?! 
Then I came across the '.pth' files, but unfortunately they only seem to 
work in some standard paths (like the before mentioned 
/usr/local/lib/python2.5/site-packages), and not in the script directory 
(like 'bin' in my case) which is automatically added to sys.path.

Can anybody think of something that could be of help here?

Thanks,
Thomas