[Python] How to use a generic function defined in Python?

I have a class and a corresponding factory function that holds some state in a closure (event_bus):

from typing import TypeVar, Generic, Callable, Any

class EventBus:

def subscribe(self):
print("Subscribed")

def publish(self):
print("Published")

T = TypeVar('T')

def create_property(event_bus: EventBus):
class Property(Generic[T]):
def __init__(self, validator: Callable[[T], bool]):
self._validator = validator

def __set_name__(self, obj: Any, name: str):
self.name = name

def __get__(self, obj: Any, type: Any) -> T:
return obj.__dict__.get(self.name)

def __set__(self, obj: Any, value: T):
if not self._validator(value):
raise ValueError("Invalid value")
obj.__dict__[self.name] = value
event_bus.publish()

def property(validator: Callable[[T], bool] = lambda x: True) -> Property[T]:
return Property(validator)

return property


Now this compiles, and the property function has the correct type: Callable[..., Property[T]]. Property can be used as a descriptor, but when I try to do so I get compiler errors:

property: Callable[..., Property[T]] = create_property(event_bus.EventBus())


class MyComponent:

width = property() # Type of "width" is partially unknown
# Type of "width" is "Property[Unknown]
height: int = property(lambda x: x > 0) # Expression of type "Property[Unknown]" is
# incompatible with declared type "int"


What am I doing wrong? How do I call the generic property function properly?

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