Module Structure/Import Design Problem

[Rafe]

Hi,

I am in a situation where I feel I am being forced to abandon a clean
module structure in favor of a large single module. If anyone can save
my sanity here I would be forever grateful.

My problem is that classes in several modules share a common base
class which needs to implement a factory method to return instances of
these same classes.

An example to help illustrate what I mean:
Lets say I have the following modules with the listed classes:
 - baselib.py   with  BaseClass
 - types.py   with  TypeA, ...
 - special.py   with  SpecialTypeA, ...

Which would be used a bit like this:
>>> type_a = any_type_instance.get_type("TypeA")
>>> special_type = type_a.get_type("SpecialTypeA")


Again, I can get around this by dumping everything in to one module,
but it muddies the organization of the package a bit. This seems like
a problem that would come up a lot. Are there any design paradigms I
can apply here?

Cheers

- Rafe