[Zope3-Users] Re: AttributeError: 'NoneType' object has no attribute '_implied'

Alec Munro alecmunro at gmail.com
Tue Aug 30 15:09:56 EDT 2005

Apparently, the problem was that the __getattr__ method in my adapter
didn't raise an AttributeError if it failed. I do know better, but I
really didn't expect it to manifest like this.

Thanks for reading, and perhaps I can save someone else the day of debugging.


On 8/30/05, Alec Munro <alecmunro at gmail.com> wrote:
> This seems to be a regression, as I believe this was working with the beta.
> I don't have it pinned down entirely, but it seems to be related to an
> Annotation adapter I am using. The error occurs in
> zope.interface.interface, at the following location:
>     def providedBy(self, ob):
>         .....
>         spec = providedBy(ob)
>         return self in spec._implied
> Printing spec gives:
> <implementedBy zope.app.pagetemplate.simpleviewclass.SimpleViewClass
> from /usr/local/Zope-3.1.0c2/lib/python/zope/app/exception/browser/systemerror.pt>
> Also, dir(spec) includes '_implied', so I really don't know what's going on.
> It isn't likely to be important, but I have commented out the import
> of the C optimized version of this method, so I could attempt to debug
> it. The error changed when I did this (it was AttributeError:
> 'NoneType' object has no attribute isOrExtends), but I assume that was
> simply because the C code was cloaking the error.
> I've attempted to track this down myself, but I really had no luck. I
> think I'll do some trial and error editing of my Annotations adapter,
> and see if that effects it.
> Thanks,
> Alec Munro

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