Last element in OrderedDict

Question

I have od of type OrderedDict. I want to access its most recently added (key, value) pair. od.popitem(last = True) would do it, but would

Answer 1

Using next(reversed(od)) is a perfect way of accessing the most-recently added element. The class OrderedDict uses a doubly linked list for the dictionary items and implements __reversed__(), so this implementation gives you O(1) access to the desired element. Whether it is worthwhile to subclass OrderedDict() for this simple operation may be questioned, but there's nothing actually wrong with this approach.