[Zope] Persistence.py does not define Persistent

[R. David Murray]

On Mon, 14 Aug 2000, Skip Montanaro wrote:
> I'm trying to publish my own module with ZServer (from Zope 2.2.0).  I get
> the following traceback:
> 
> 	from Persistence import Persistent
>     ImportError: cannot import name Persistent
> 
> When I look at lib/python/Persistence.py, all I see is a copyright notice
> and the following short doc string:
> 
>     """Provide access to Persistent and PersistentMapping
> 
>     This avoids dependency on the database package name.
>     """
> 
> I can't find a definition of an object named Persistent (probably ought to
> be a class or ExtensionClass, based upon the usage I saw) anywhere in the
> Zope 2.2.0 tree.

The comment implies it should work.  There's a cPersistent in the
ZODB directory, which I think is the ExtensionClass you are looking
for.  from ZODB.cPersistence import Persistent seems to do
something...but PersistentMapping.py in the ZODB directory just
does an 'import Persistence', so I don't see why that doesn't work
when I try it from the python command line.

--RDM