What about ob.getPhysicalPath()? This is unique for every placeful Zope object. You can then resolve it back out to an object via restrictedTraverse. These methods are documented in the help system and the nebulous Interfaces wiki.

Others (myself included) have asked this same question. To date, I've not seen a satisfactory answer. Most object databases provide a unique identifier (an oid) to a given object. That reference can be stored in other objects for use when necessary. Good object databases are capable of establishing relationships between objects that are maintained. To my knowledge, Zope doesn't work that way. Instead, it uses the URL as a pseudo oid.

I think you actually mean the physical path. The URL of an object can change as a result of virtual hosting, but an object's physical path never changes unless you move it.

This has both good and bad points. URL use is handy for web integration, but you give up the standard oid paradigm and is another reason why Zope is hard to grok. (But it is one of the reasons why Zope is so justly admired.)

Note that Zope is just Python, and as such, you can also use object references in unrestricted code for the same purpose, e.g.: ref = Folder1.foo Folder2.bar = ref This is a facility that is not exposed to unrestricted code for security reasons, but it definnitely exists. It's how Zope works. ;-) -- Chris McDonough Zope Corporation http://www.zope.org http://www.zope.com "Killing hundreds of birds with thousands of stones"