While there is documentation that dict.keys(), dict.values(), and dict.items() are now view objects(https://docs.python.org/3/library/stdtypes.html#dict-views), there's no mention dictviews, dict_keys, dict_values, and dict_items not being built-ins. This is confusing because type(dict.keys()) returns dict_keys, type(dict.values()) returns dict_values, etc., and the documentation uses `dictview` as the object signature, and so it's unclear how to do object introspection on dictview objects. 

The #python-dev channel suggested that the canonical way to do the object introspection is to use the collections.abc.mapview types; the documentation for dicts should reflect this (and that dictview and the rest are not __builtin__ types/in the python namspace).