Non-caching import?

[Kevin Smith]

Is it possible to implement an import mechanism that will not use the caching 
mechanism?  For example,  let's say that I have the following file/directory 
structure.  The only difference between the two structures is that 
/home/lib/more.py has an extra class "Blech" defined.

/usr/lib/python/site-packages/:
   foo.py:
      from more import *
      class Bar: pass
   more.py:
      class Blah: pass

/home/lib/:
   foo.py:
      from more import *
      class Bar: pass
   more.py:
      class Blah: pass
      class Blech: pass

Now we run the following code...

# Import foo from /usr/lib/python/site-packages/.
import foo

# Insert the directory into the path where the other foo.py exists.
sys.path.insert(0, '/home/lib/')

# Import foo again (hopefully from /home/lib/).
import foo

After the second import, there are no changes to foo.  Class Bar is still the 
class definition from site-packages/foo.py.  I can get Bar from the second 
import to act the way I would like by doing a "del sys.modules['foo']" after 
the first import, but this has no effect on the "from more import *" in 
foo.py.

So I end up not having access to class Blech, and Blah is still from 
site-packages/foo.py because the caching mechanism blocked them from being 
loaded from /home/lib/foo.py.  Is there a way around this (possibly using 
__import__())?

P.S. Keep in mind that this is a very simple example case and that I am not 
trying to use the above code verbatim, so please refrain from simply 
correcting poor programming practices in this example.


Kevin Smith
Kevin.Smith at sas.com