Open
Description
Bug Report
The function
def get_value(key: CombinedDictKey, mapping: CombinedDict):
return mapping[key]raises an error when mapping is a union of two TypedDicts and key is a union of two Literals containing the keys of those TypedDicts. It works when typed with just one of the Literals and TypedDicts.
To Reproduce
from typing import Literal, TypedDict, Union
class DictA(TypedDict):
x: int
y: int
class DictB(TypedDict):
z: str
class DictAB(DictA, DictB):
pass
DictAKey = Literal["x", "y"]
DictBKey = Literal["z"]
DictABKey = Union[DictAKey, DictBKey]
dict_a = DictA(x=1, y=2)
dict_b = DictB(z="z")
dict_ab = DictAB(**dict_a, **dict_b) # type: ignore # Unrelated issue #11108
def get_value_from_A(key: DictAKey, mapping: DictA):
return mapping[key] # Passes type check as expected
def get_value_from_B(key: DictBKey, mapping: DictB):
return mapping[key] # Passes type check as expected
def get_value_from_AB(key: DictABKey, mapping: DictAB):
return mapping[key] # Fails type check with error: TypedDict key must be a string literalExpected Behavior
return mapping[key] passes typing in all three cases.
Actual Behavior
In the case of get_value_from_AB, return mapping[key] raises error: TypedDict key must be a string literal; expected one of ("z", "x", "y"). This is unexpected as it passes for the functions typed with only one of DictA or DictB.
Your Environment
- Mypy version used: 0.991
- Python version used: 3.11.0