On 18/01/13 11:11, Jose Amoreira wrote:
Suppose I have a list l_obj of similar objects. Is there any way I can generate a list l_prp of references to a given property of those objects in such a way that, if change the value of one element in l_prp, the corresponding object in l_obj gets its property updated, and vice-versa?
Not easily, and for very good reason, it breaks one of the fundamental principles of OOP. Objects should manage their own data and clients should manage the objects.
So getting a list of the prp values is fine. Trying to modify those values without going through the object is asking for trouble and creating a nightmare for debugging. So unless you have a very specific reason to do so just modify the objects prp through the object.
As expected, changes in l_prp do not change the properties of the elements in l_obj, neither do changes in l_obj's element's properties change the values in l_prp.
As you say, it's as expected and very worrying if it did otherwise!
Is there a simple way to implement such connections?
It's difficult by intent. It's to save you from yourself. Is there a good reason to want to do such a thing? -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
