POOP / Python (Object Oriented Persistence) ?

[Jim Fulton]

Andrew Kuchling wrote:
> 
> "Tony J Ibbs (Tibs)" <tony at lsl.co.uk> writes:
> > OK - I've lost one snag, so here's a new one (although much less
> > important) - it's not clear (from the web pages) how to install the ZODB if
> > one *doesn't* care about Zope in general - *presumably* one has to download
> > the standard Zope distribution and just answer some questions?
> 
> I've submitted setup.py scripts that use the Distutils to install just
> ExtensionClass, or just the ZODB, and makes it pretty easy.  Brian
> Lloyd at Digicool, who's responsible for Zope releases, has said that
> the scripts will get looked at after Zope 2.2final ships; I'd guess
> that will happen in a week or so.  I'm pushing hard to get the ZODB
> packaged separately, because it'll be hard to use in Python
> applications if you can only get it by downloading all of Zope.

FWIW, we want to see ZODB packages separately too. Soo much to 
do, so little time. Waaaaaaaa.

> > I still think someone should be pushing this more...
> 
> Agreed; the ZODB is really quite cool!  At work we're beginning to use
> ZODB for storing business-related objects, and it's an interesting
> learning experience.  The major issues so far are:
> 
>         1) lack of documentation, particularly for various advanced
>         properties of the ZODB.

Sigh.

>         2) the use of ExtensionClass means that the standard Python
>         isinstance() doesn't work any more, so you need to use a
>         modified version. 

FWIW I provided a patch to isinstance to make it work with 
ExtensionClass and AFAIK, the patch got checked in, so
isinstance should work with ExtensionClass in the next 
release of Python and in the Python CVS.

>         We've also hit things like ExtensionClass
>         not supporting __radd__; the resulting symptoms are often
>         mysterious and it's time-consuming to pin down what the
>         problem is.

Yes, unfortunately, the numeric protocol is a weakness because
it's hard and because we (Zope) don't rely on it much. I'd love to
see it improved. For that matter, I'd love to see some future
release of Python render ExtensionClass unnecessary.
 
>         3) lack of an easy installation method, which is why I wrote
> the setup.py scripts.

Thanks. :)

Jim

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