This is the kind of ad-hoc PEP proposal that could be completely avoidable if there was a generic modifier or initialization/declaration construction for declaring a variable as constant. So incredibly simple, so incredibly useful that it's hard to believe that it hasn't been accepted yet (it was proposed).

Something interesting to note is that Python’s ContextVar (introduced in Python 3.7) is a persistent dictionary.

https://www.python.org/dev/peps/pep-0567/#implementation

Nice I like having persistent structures available. Then I don't have to safeguared against unintended modifications.