Closed
Description
this seems to be a regression which I am getting with mypy master @ 0df8cf5, havent bisected to find the exact commit:
from typing import Dict
from typing import Generic
from typing import List
from typing import Tuple
from typing import TypeVar
from typing import Union
class Thing:
pass
_THING = TypeVar("_THING", bound="Thing")
class ThingCollection(Generic[_THING]):
_collection: List[Tuple[str, _THING]]
_index: Dict[Union[None, str, int], _THING]
def __init__(self, t: _THING):
self._collection = [("x", t)]
self._index = {}
def do_thing(self) -> None:
self._index.update(
(idx, c) for idx, (k, c) in enumerate(self._collection)
)
def do_thing_workaround(self) -> None:
self._index.update(
(idx, c) for idx, c in enumerate(c for (k, c) in self._collection)
)output:
$ mypy test3.py
test3.py:27: error: Generator has incompatible item type "Tuple[int, Tuple[str, _THING]]"; expected "Tuple[Union[None, str, int], _THING]" [misc]
Found 1 error in 1 file (checked 1 source file)
mypy seems to be mis-interpreting the first generator. works in mypy 0.942 and pyright