New In Python 3.15: frozendict

I suppose everybody starting out with Python and discovering that
tuples were available as an immutable alternative to lists, and
frozensets as an immutable alternative to sets, has wondered why dicts
were the odd one out in this.

Well, this omission is finally being fixed with the introduction of
frozendicts in Python 3.15 <https://peps.python.org/pep-0814/>.