Maybe it's possible to allow "/path/to/zipfile.zip/subdirectory/etc/" in sys.path? That sounds better than picking a random new character as delimiter.
Fine by me. From a java POV the bang ("!") was not random:
import java java.lang.Class.getResource(type(1), "/java/lang/Class.class")
The URL library in java can of course open the string above as an input stream.
I guess the advantage of this notation is that it makes a simple check for "file inside zip archive" possible; I sort of like that. The downside is that it limits the use of "!" for other reasons in pathnames (which seems a mostly but not entirely theoretical problem).
I assume that as long as some module exists with a __path__ like this, it not possible to clear the cached entries for /C/D/E/Archive.zip.
If importing from zip is regarded mainly as a deployment/bootstrapping feature, then the cleanup issues does not exist. I have no problem looking at it as a deployment feature (that is all I need it for myself), I just didn't dare to put such a limit on my jython implementation.
I don't see sys.path as a very dynamic thing anyway. It gets manipulated briefly at the beginning, and then maybe, rarely, stuff gets added during the program run. I've seen temporary additions, but these were usually in the test suite.
--Guido van Rossum (home page: http://www.python.org/%7Eguido/)