How about making an immutabledict class where the value is covariant?

[spacether]

How about making an immutabledict class where the value is covariant?
Other immutable containers are all covariant (Union, Tuple Sequence etc).
Because the _K is by default not covariant, my type hints did not work when they should have.
This was uncovered here: python/mypy#15710

Note: the copy method must be removed if you do that per pylance or mypy

[sterliakov]

To add on this, you won't have to remove the copy method. It could be

def copy(self, **add_or_replace: _U) -> immutabledict[_K, _V | _U]: ...

to resolve variance issues (with add_or_replace: _V _V cannot be covariant), where _U is another unbound type variable. Since your mapping is immutable, why constraint users in creating another instances with different types?

[corenting]

Fixed with #244 , closing the issue