MyPy 1.11.0 loop variable persistance #17541
Description
Bug Report
In MyPy version 1.11.0, the type inference for loop variables seems to persist across different loops when the same variable name is used. This behavior differs from MyPy version 1.10.1, where the code works without issues.
To Reproduce
from functools import WRAPPER_ASSIGNMENTS, WRAPPER_UPDATES
class Test:
def test(self) -> None:
self.stage_fn = lambda x: x
for attr in WRAPPER_ASSIGNMENTS:
object.__setattr__(self, attr, getattr(self.stage_fn, attr))
for attr in WRAPPER_UPDATES:
getattr(self, attr).update(getattr(self.stage_fn, attr, {}))Expected Behavior
In previous versions, this did not raise an issue.
Actual Behavior
test.py:9: error: Incompatible types in assignment (expression has type "Literal['__dict__']", variable has type "Literal['__module__', '__name__', '__qualname__', '__doc__', '__annotations__']") [assignment]
Found 1 error in 1 file (checked 1 source file)
This is seemingly fixed by changing the loop variables
for attr_1 in WRAPPER_ASSIGNMENTS:
object.__setattr__(self, attr_1, getattr(self.stage_fn, attr_1))
for attr_2 in WRAPPER_UPDATES:
getattr(self, attr_2).update(getattr(self.stage_fn, attr_2, {}))
This workaround should not be necessary, as loop variables should be scoped independently.
Your Environment
mypy==1.11.0
mypy-boto3-s3==1.34.138
mypy-extensions==1.0.0
pyproject.toml:
[tool.mypy]
explicit_package_bases = true
files = "src,test"
mypy_path = "src"
plugins = ["pydantic.mypy"]
strict = true