I can't remember for certain. I know that in some places where a similar change was made a list rather than a view is required in code that follows on from the change. It may be that I changed it in several places without actually needing to do it in all the places that I did.

The view concept comes in new in Python 3. It's neither a list nor a generator and though it can iterate it's not quite a normal iterator (in the old sense). At this exact minute though, I can't remember the details. Basically I did the changes that made things work rather than being theoretical about it...