Documentation

Keys views are set-like since their entries are unique and :term:hashable. If all values are hashable, so that (key, value) pairs are unique and hashable, then the items view is also set-like. (Values views are not treated as set-like since the entries are generally not unique.) For set-like views, all of the operations defined for the abstract base class :class:collections.abc.Set are available (for example, ==, <, or ^). While using set operators, set-like views accept any iterable as the other operand, unlike sets which only accept sets as the input.

> {1:2, 3:4}.items() >= {1:2}.items()
True
> {1:[2], 3:4}.items() >= {1:[2]}.items()
True
> set({1:[2], 3:4}.items())
TypeError: unhashable type: 'list'

It seems like this documentation is not accurate. dict.items() does have set operations even when the values are not hashable.

See also: https://stackoverflow.com/questions/77399592/set-like-behaviour-of-dict-items-for-non-hashable-values

Linked PRs

• gh-111622: Fix doc for items views #112051
• [3.12] gh-111622: Fix doc for items views (GH-112051) #112052