[Python] Decorating python properties with an observable pattern

I'm trying to create an observable decorator that adds the method "add_observer" to a property. The main issue I'm having is that I do not know how to treat the getter. It would be amazing if I could extend the underlying property with the method somehow.

class observable:
def __init__(self, fget):
self.observers = []
self.fget = fget
self.fset = None
self.name = fget.__name__

def add_observer(self, observer):
self.observers.append(observer)

def setter(self, fset):
self.fset = fset
return self

def __set__(self, obj, value) -> None:

if self.fset is None:
raise AttributeError(f"Setter not defined for property {self.name}")
self.fset(obj, value)

for observer in self.observers:
observer(value)

def __get__(self, obj, objtype=None):
return self


class Options:

def __init__(self):
self._debug: bool = False

@observable
def debug(self) -> bool:
return self._debug

@debug.setter
def debug(self, debug: bool):
self._debug = debug


opt = Options()
print(opt.debug)
opt.debug.add_observer(lambda value: print(f"Debug is {value}"))
opt.debug = True
opt.debug = False


<__main__.observable object at 0x7f446f854500>
Debug is True
Debug is False


I cannot use opt.debug as a boolean value. I tried alternatives such as modifying the owner with owner.add_observable(owner.debug, lambda x: 'hello!') which is pretty close to what I want but not close enough. Mostly because I wanted autocomplete to work.

Also, I'm getting a shadowing error on the IDE that @property does not trigger, how come?:

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