Dictionary, iterate & update objects

[Caleb Hattingh]

jansenh wrote:
> hi comp.lang.python.
>
> I need some newbe advice on idiomatic use of Python dictionaries.
>
> I have service with a dictionary which holds a bunch of objects as
> values, and an ID as key to each object. Then I want to change an
> objects state based on its key. The way I am doing this now is by using
> 'fromkeys' and copying my object over in a temporary dictionary, then
> manipulating the object, and then I do an 'update' back to the main
> dictionary..  :-0

It would be easier to help if you post a short snippet of code that
demonstrates the essence of the issue, but I made an attempt at coding
what you describe:

>>> d = {}
>>> class o(object):
... 	def __init__(self):
... 		self.x = 0
...
>>> i = o()
>>> d[12345]=i
>>> temp=d[12345]
>>> temp.x = 5
>>> d[12345].x
5
>>> i.x
5
>>>

After I assign the object to the dict with ID=12345, I can easily get
the object by its key and manipulate its state.  The last 4 lines show
that the state changed for all the active references to the created
object.   Is this what you wanted?

If you are this Henning Jansen:

http://www.henning-jansen.com/

you may get a lot much more accurate help from others in this group by
mentioning that you have some Ruby experience.   That way, the guys in
here who also know Ruby (not me :) can quickly point out the
differences in behaviour for your specific question.

Regards
Caleb