Getting a dictionary from an object

Mike Meyer mwm at mired.org
Sat Jul 23 19:50:36 CEST 2005


Steven D'Aprano <steve at REMOVETHIScyber.com.au> writes:
> On Sat, 23 Jul 2005 11:48:27 +0300, Thanos Tsouanas wrote:
>> Hello.
>> 
>> I would like to have a quick way to create dicts from object, so that a
>> call to foo['bar'] would return obj.bar.
>
> That looks rather confusing to me. Why not just call obj.bar, since it
> doesn't look like you are actually using the dictionary at all?

Well, I needed exactly this functionality last week. I have a
collection of (rather messy) classes that have a slew of attributes as
values. I would have used a dictionary for this, but I didn't write
the code.

I have to be able to display these objects (in HTML, if it matters),
and have as a requirement that the format string live in a database.

My solution didn't look to different from dictobj. There's some extra
mechanism to fetch the format string from the database, and some
formatting of the attribute based on meta-information in the object,
but it's the same basic idea.

>> class dictobj(dict):
>>     """
>>     class dictobj(dict):
>>     A dictionary d with an object attached to it,
>> 	which treats d['foo'] as d.obj.foo.
>>     """
>>     def __init__(self, obj):
>>         self.obj = obj
>>     def __getitem__(self, key):
>>         return self.obj.__getattribute__(key)
>
> I don't think this is particularly useful behaviour. How do you use it?

    def __str__(self):
        return self._format % self


        <mike
-- 
Mike Meyer <mwm at mired.org>			http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.



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