Please don't do this, there are far better approaches. Use dataclasses/attrs that are frozen for immutable record types.

(Specifically avoid namedtuples unless you're hoisting a tuple to a real record. Record types also being a weird union with a tuple is...oft confusing)

For immutable basic data types, adopt type annotations and prefer to use sequence/iterable and mapping to direct didn't/list types. These provide statically verifiable immutability and also allow begin to encourage useful async-friendly patterns.

Since PEP 591 [1], if using mypy with Python 3.8+ or the typing_extensions module, you can also take advantage of typing.Final, which lets you statically verify something isn't changed. The catch is that it isn't enforced at runtime.

  [1]: https://www.python.org/dev/peps/pep-0591/

...or `dataclass(frozen=True)` if you need the ergonomics.

For non-primitive members, `frozenset` is in the standard library, but frozen dictionaries are unfortunately lacking.

I second this. My current job is the first place I've worked where the convention is to use NamedTuples for most things I've seen dicts used for on past projects and I quite like the pattern. It both makes the code more readable and avoids a number of subtle bugs that can crop up.

Sure, we'll do all that. In the mean time, could you please get started on getting the _rest_ of the community to adopt that as a well established idiom and then also have them initiate efforts to adapt popular libraries/frameworks so that they implement the adopted idioms?

Would Thursday be a good time to checkpoint on this?

Thank you so much.

I’ll research those, thanks. Any suggestions for OSS projects that do so today?