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.
http://mypy.readthedocs.io/en/latest/cheat_sheet_py3.html#st...