fix some typing

pyproject.toml

@@ -55,7 +55,7 @@ known-first-party = ["numpy", "pandas"]
 source = ["src"]
 
 [tool.mypy]
-python_version = 3.8
+python_version = "3.9"
 platform = "posix"
 
 color_output = true

src/impunity/visitor.py

@@ -148,8 +148,8 @@ def get_annotation_unit(self, node: ast.expr) -> Optional[str]:
 
         elif isinstance(node, ast.Subscript):
             if isinstance(node.slice, ast.Index):
-                if isinstance(node.slice.value, ast.Tuple):
-                    unit_node = node.slice.value.elts[1]
+                if isinstance(node.slice.value, ast.Tuple):  # type: ignore
+                    unit_node = node.slice.value.elts[1]  # type: ignore
             elif isinstance(node.slice, ast.Tuple):
                 unit_node = node.slice.elts[1]
             if isinstance(unit_node, ast.Constant):

tests/sample_module.py

@@ -1,12 +1,12 @@
 from typing import Any
 
-from typing_extensions import Annotated
+from typing_extensions import Annotated, TypeAlias
 
 import numpy as np
 import numpy.typing as npt
 from impunity import impunity
 
-NDArrayFloat = npt.NDArray[np.float64]
+NDArrayFloat: TypeAlias = npt.NDArray[np.float64]
 meters = Annotated[NDArrayFloat, "m"]
 seconds = Annotated[float, "s"]
 meters_per_second = Annotated[NDArrayFloat, "m/s"]