[Zope-Coders] Re: [ZC] 490/ 2 Resolve ""Object" class for PythonScripts"

[Evan Simpson]

Casey Duncan wrote:
> Why a __setitem__ as opposed to __setattr__? Is it because that is forbidden 
> in general in the bytecode interpreter?

It's not opposed to __setattr__, it's in addition.  '_guarded_writes' 
allows attributes and items to be set, and the base 'record' class 
already provides __getitem__, so a __setitem__ was all it needed.

> I'm a little confused what this gains us over just using a dict (but I am 
> happy to be enlightened). Also this should be documented somewhere, like the 
> scripting section of the Zope book ;^)

It's useful for constructing data structures for code that expects an 
object, not a dict.  It's the difference between <dtml-in foo> and 
<dtml-in foo mapping>, for example.  An Object makes a fine stand-in 
where a :record or :records marshalled field was expected.

I'll definitely send Chris a snippet for the Book.

Cheers,

Evan @ 4-am