[Jim Fulton]
Here's an example that I hope will be motivating:
Suppose Marc-Andre has a package mx with subpackages DateTime and stringtools. ... Zope has a notion of products which are *self contained* packages that are sub-packages of the Products package. So, suppose someone wants to write a NiftyDB product, which is a Zope product that provides access to an external database. Now the author of the NiftyDB product wants to use the mx package. The mx package is not a standard part of Zope, or of Python, so they simpley include it in the NiftyDB product directory.
This would motivate me to strangle the author of NiftyDB. He should say "This requires Marc-Andre's mx package", and put error handling on the import. Otherwise I might end up with a gazillion separate copies of the mx package installed on my system and no way to clean it up. Your notion of "self contained packages" is flawed. Reducto ad adsurdum, it leads to downloading the OS with every app you install. (Crap, I hope I haven't given Sun any new ideas...). - Gordon