Ok... I wrong. The array of items have a NULL key and value if one item is deleted. Sorry for the confusion.

On Sat, 1 Aug 2020 at 01:09, Guido van Rossum <guido@python.org> wrote:
the key and items views already implement the Set ABC, and I'd rather refrain from having them *also* implement the Sequence ABC.

I'm not pro or against the proposal, but maybe count it's not useful at all for keys and items. Furthermore, dict implements __reversed__, that is not a Mapping method, but it's a Sequence method.

I think that it's useful to implement methods of other APIs without changing their name or implement the full other API... if it's useful ^^ But maybe I'm missing something in the general picture.