I'm aware that Python scripts (as opposed to Extension methods) do not have access to the entire Python library, but I'm confused by the following and would appreciate both an explanation and, if it's possible, instructions for setting things up so that (during development) what I tried to do would be permitted. At the beginning of one of my Python scripts I put: import pdb pdb.set_trace() which I had gotten used to doing in my product's Python code. It doesn't complain about the import (which, in retrospect, surprises me, since I thought there were only a small number of library modules that could be imported). However, when it gets to the pdb.set_trace(), it prompts for a login name and password (even though I'm already logged in) and doesn't accept mine. When I finally cancel out of the repeated login prompts, it gives me the following error: Site Error An error was encountered while publishing this resource. Unauthorized Access denied for because its container, , has no security assertions. .... File Script (Python), line 2, in TestScript (Object: guarded_getattr) File /Zope/zope/lib/python/AccessControl/ZopeGuards.py, line 122, in guarded_getattr (Object: pdb) File /Zope/zope/lib/python/AccessControl/SecurityManager.py, line 149, in validate File /Zope/Zope-2.4.0/lib/python/Products/ZDebug/DebugSecurityPolicy.py, line 185, in validate (I don't know why the container is blank.) In retrospect, I would have thought that access would be categorically denied as being unsafe from the web. However, the error message implies that it would be allowed if I had the right security assertions set up. How would I do that (if it is indeed possible)?