self-aware list of objects able to sense constituent member alterations?

[koranthala]

On Jan 28, 2:16 am, Reckoner <recko... at gmail.com> wrote:
> I'm not sure this is possible, but I would like to have
> a list of  objects
>
> A=[a,b,c,d,...,z]
>
> where,  in the midst of a lot of processing I might do something like,
>
> A[0].do_something_which_changes_the_properties()
>
> which alter the properties of the object 'a'.
>
> The trick is that I would like A to be mysteriously aware that
> something about the  object 'a' has changed so that when I revisit A,
> I will know that the other items in the list need to be refreshed to
> reflect the changes in A as a result of changing 'a'.
>
> Even better would be to automatically percolate the subsequent changes
> that resulted from altering 'a' for the rest of the items in the list.
> Naturally, all of these items are related in some parent-child
> fashion.
>
> that might be a lot to ask, however.
>
> Any advice appreciated.

I think Python Cookbook has a recipe which deals with this.
- 6.12 Checking an Instance for Any State Change.