[Zope-CMF] Re: Content types based on Python objects

Philipp von Weitershausen philipp at weitershausen.de
Wed Nov 28 13:49:07 EST 2007

Charlie Clark wrote:
> Am 28.11.2007 um 14:03 schrieb Charlie Clark:
>> class Grid(dict, PortalContent)
>> ...
>> TypeError: Error when calling the metaclass bases multiple bases have 
>> instance lay-out conflict
> Looks like using the old favourite UserDict solve the incompatability 
> problem.
> class Grid(UserDict, PortalContent):
> ...

Right. You can't mix built-in types with ExtensionClasses (pretty much 
anything in Zope 2 is an ExtensionClass). Actually, subclassing the 
built-in types usually only works for trivial cases.

UserDict (or PersistentDict) is the right thing to use here.

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