Table of collection data types in Python

python_collections.mediawiki

container	ordered members?	unique members?	immutable type?	used for keys in
	No	No	No
	No	No	Yes
set	No	Yes	No	dict
frozenset	No	Yes	Yes
list	Yes	No	No
tuple	Yes	No	Yes
OrderedSet	Yes	Yes	No	OrderedDict
	Yes	Yes	Yes

Looks like Python treats uniqueness and order as mutually exclusive (unique XOR ordered).

An implementation of the last line would likely be called OrderedFrozenSet or FrozenOrderedSet.

Reorganized table to make patterns more apparent.