That's right, mirroring the built in (3.x) abc collections heirarchy. Which then allows you to do interesting things like delegation based polymorphism by regis

That's right, mirroring the built in (3.x) abc collections heirarchy. Which then allows you to do interesting things like delegation based polymorphism by registering with the appropriate metaclass so - just to come back to your parent's point - interrogating the type reveals it to be list-like or dict-like.