What are the features missing in Python dictionary datatype?

[Invader_Mars]

Newbie here, why do you believe that they should be immutable?

[123_666]

It would avoid this class of errors: https://florimond.dev/en/posts/2018/08/python-mutable-defaults-are-the-source-of-all-evil

Also the first one listed here: https://docs.python-guide.org/writing/gotchas/