Project source code layout?

[Lawrence D'Oliveiro]

In message <mailman.1158.1244174209.8015.python-list at python.org>, Dave Angel 
wrote:

> Rather than editing the source files at install time, consider just
> using an environment variable in your testing environment, which would
> be missing in production environment.

I'd still need to define that environment variable in a wrapper script, 
which means editing that script at install time ... back to square one ...