[ZODB-Dev] PersistentMapping in BTrees

[Thomas Guettler]

Hi ZODB gurus,

I want to store instances of a class which derives from
PersistentMapping in a OOBTree.

Now I am looking for a way to write the __cmp__ method. Is there
something like an id() method for persistent objects? I know addresses
of references get lost since they are not persistent. Is there
something like a persistent reference?

In some code I found self._p_oid, but it is empty for my objects.

I use ZODB3 and python2.2.2.

Would it be better to use ZODB4?

 thomas


-- 
Thomas Guettler <guettli at thomas-guettler.de>
http://www.thomas-guettler.de