No value

Sentinel values to express missing keys or values, where None has it's own meaning, for example in jsom

warn: does not support static analysis (there is not way to make it right now)

Examples:

from no_value import NoValue 
def update_some_value(val: int | None | NoValue) -> None:
    if isinstance(val, int):
        print(f'set something to {val}')
    elif val is None:
        print(f'clear value')
    elif val is NoValue:
        print("do nothing")


update_some_value(17)
update_some_value(42)
update_some_value(NoValue)
update_some_value(None)

Will

set something to 17
set something to 42
do nothing
clear value