diff --git a/t4_devkit/cli/sanity.py b/t4_devkit/cli/sanity.py
index 14aba58..b83e064 100644
--- a/t4_devkit/cli/sanity.py
+++ b/t4_devkit/cli/sanity.py
@@ -26,9 +26,7 @@ def _run_sanity_check(
 ) -> list[DBException]:
     exceptions: list[DBException] = []
 
-    db_dirs: list[Path] = Path(db_parent).glob("*")
-
-    for db_root in tqdm(db_dirs, desc=">>>Sanity checking..."):
+    for db_root in tqdm(Path(db_parent).glob("*"), desc=">>>Sanity checking..."):
         result = sanity_check(db_root, revision=revision, include_warning=include_warning)
         if result:
             exceptions.append(result)
diff --git a/t4_devkit/common/converter.py b/t4_devkit/common/converter.py
index 8f74a38..0254b9d 100644
--- a/t4_devkit/common/converter.py
+++ b/t4_devkit/common/converter.py
@@ -11,17 +11,13 @@
 __all__ = ["to_quaternion"]
 
 
-def to_quaternion(value: ArrayLike | NDArray) -> Quaternion:
+def to_quaternion(x: ArrayLike | NDArray) -> Quaternion:
     """Convert input rotation like array to `Quaternion`.
 
     Args:
-        value (ArrayLike | NDArray): Rotation matrix or quaternion.
+        x (ArrayLike | NDArray): Rotation matrix or quaternion.
 
     Returns:
         Quaternion: Converted instance.
     """
-    return (
-        Quaternion(matrix=value)
-        if isinstance(value, np.ndarray) and value.ndim == 2
-        else Quaternion(value)
-    )
+    return Quaternion(matrix=x) if isinstance(x, np.ndarray) and x.ndim == 2 else Quaternion(x)