Closed
Description
Considering this self-contained example:
from typing import TypeVar, overload
_S = TypeVar("_S", bound="Descriptor")
_M = TypeVar("_M", bound="Model")
class Descriptor:
@overload
def __get__(self: _S, obj: None, objtype: type[_M]) -> _S:
...
@overload
def __get__(self, obj: _M, objtype: type[_M]) -> str:
...
def __set__(self, obj, value: str):
...
class Model:
foo = Descriptor()
foo2 = Descriptor()
def some_method_that_sets_foo2(self):
self.foo2 = "abc"
reveal_type(Model.foo)
reveal_type(Model.foo2)Running pyright gives the following
> pyright foobar.py
No configuration file found.
No pyproject.toml file found.
stubPath /tmp/typings is not a valid directory.
Assuming Python platform Linux
Searching for source files
Found 1 source file
/tmp/foobar.py
/tmp/foobar.py:28:13 - info: Type of "Model.foo" is "Descriptor"
/tmp/foobar.py:29:13 - info: Type of "Model.foo2" is "Descriptor | str"
1 error, 0 warnings, 4 infos
Completed in 0.558sec
The fact that there exists a method that sets foo2 makes the typing for the descriptor being retrieved from the class to consider that now he can return that too, which is wrong since I'm setting it through object and not class. Also, setting it by class (i.e. Model.foo = <something else> would change it to something else and not call __set__).
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