autoflake
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PyCQA
incorrectly removes unused variable when surrounded in typing
Running autoflake --remove-all-unused-imports on this file
from typing import List, TYPE_CHECKING
if TYPE_CHECKING:
from pandas import DataFrame
def foo(a: List["DataFrame"]) -> None:
print(a[0].size)
produces
from typing import List, TYPE_CHECKING
if TYPE_CHECKING:
pass # <----
def foo(a: List["DataFrame"]) -> None:
print(a[0].size)
i.e. it removes the DataFrame import despite the type being used. I think this is because it is enclosed in the List because if I include "DataFrame" as a top-level type, the import is retained, as expected:
# this example stays the same
from typing import List, TYPE_CHECKING
if TYPE_CHECKING:
from pandas import DataFrame
def foo(a: "DataFrame") -> None:
print(a.size)
A temporary workaround for this is to add a line such as:
if TYPE_CHECKING:
from pandas import DataFrame
DataFrame # Prevent autoflake from removing imports. pylint: disable=pointless-statement
But I hope that this will eventually be fixed as such lines are ugly. :smile:
I just add a # noqa on the import line so it doesn't get removed, easier than the no-op DataFrame you have. But of course then if you later remove the typing that refers to DataFrame, autoflake won't clean it up for you automatically.