How to distribute code with required modules?

[Roy Smith]

I work in a shop that uses a lot of perl for internal tools.  I've been 
writing stuff (again, internal tools) in python, and trying to figure out a 
way to get the language to be more accepted.  Yesterday, I hit upon a 
stumbling block.

The way we distribute tools is we just check them into a tools CVS module.  
Everybody does "cvs update" on a regular basis, and gets any new tools that 
have been added to the repository.  I've written a lot of python classes 
for handling the types of data files we work with.  All of my tools depend 
on some combination of those classes.  I created a subdirectory of tools 
called pylib, and check all my class modules into there.  Then I set by 
PYTHONLIB environment variable to "$HOME/sandbox/src/tools/pylib".

So, here's the problem.  Somebody goes to run one of my tools, and it can't 
find my classes.  I explain to the guy that he just needs to set PYTHONPATH 
and all will be well.  I get a bit of pushback because none of his perl 
tools require you to set a PERLLIB" variable; he just has code which looks 
at $0, chops off the last component (leaving the directory from which the 
script was run), and then appends the name of the module he wants:

if ($0 =~ m/(.*\/)/) {
    $rundir = $1;
}
require "$rundir/module.pm";

He thinks my python scrips should do something similar (which would 
certainly be possible).  I'm trying to convince him that it would be very 
un-pythonic to do it that way.

Any thoughts?