diff --git a/fastkml/features.py b/fastkml/features.py
index e32be911..2cc1b4a3 100644
--- a/fastkml/features.py
+++ b/fastkml/features.py
@@ -462,10 +462,10 @@ def _get_kwargs(
             kwargs["description"] = description.text
         visibility = element.find(f"{ns}visibility")
         if visibility is not None and visibility.text:
-            kwargs["visibility"] = visibility.text in ["1", "true"]
+            kwargs["visibility"] = visibility.text in {"1", "true"}
         isopen = element.find(f"{ns}open")
         if isopen is not None:
-            kwargs["isopen"] = isopen.text in ["1", "true"]
+            kwargs["isopen"] = isopen.text in {"1", "true"}
         address = element.find(f"{ns}address")
         if address is not None:
             kwargs["address"] = address.text
@@ -541,7 +541,8 @@ def __init__(
             extended_data=extended_data,
         )
         if kml_geometry and geometry:
-            raise ValueError("You can only specify one of kml_geometry or geometry")
+            msg = "You can only specify one of kml_geometry or geometry"
+            raise ValueError(msg)
         if geometry:
             kml_geometry = create_kml_geometry(  # type: ignore[assignment]
                 geometry=geometry,
diff --git a/fastkml/geometry.py b/fastkml/geometry.py
index 884a03f7..e97c7641 100644
--- a/fastkml/geometry.py
+++ b/fastkml/geometry.py
@@ -771,4 +771,5 @@ def create_kml_geometry(
                     geometry=geom,
                 ),
             )
-    raise KMLWriteError(f"Unsupported geometry type {type(geometry)}")
+    msg = f"Unsupported geometry type {type(geometry)}"
+    raise KMLWriteError(msg)
diff --git a/fastkml/styles.py b/fastkml/styles.py
index 2c41d70f..17ae6100 100644
--- a/fastkml/styles.py
+++ b/fastkml/styles.py
@@ -871,7 +871,7 @@ def _get_kwargs(
             key = pair.find(f"{ns}key")
             style = pair.find(f"{ns}Style")
             style_url = pair.find(f"{ns}styleUrl")
-            if key is None or key.text not in ["highlight", "normal"]:
+            if key is None or key.text not in {"highlight", "normal"}:
                 raise ValueError
             elif key.text == "highlight":
                 if style is not None:
diff --git a/fastkml/views.py b/fastkml/views.py
index 4a488eb9..e94e80ab 100644
--- a/fastkml/views.py
+++ b/fastkml/views.py
@@ -198,19 +198,19 @@ def etree_element(
             )
             tilt.text = str(self.tilt)
         if self.altitude_mode:
-            if self.altitude_mode in (
+            if self.altitude_mode in {
                 AltitudeMode.clamp_to_ground,
                 AltitudeMode.relative_to_ground,
                 AltitudeMode.absolute,
-            ):
+            }:
                 altitude_mode = config.etree.SubElement(  # type: ignore[attr-defined]
                     element,
                     f"{self.ns}altitudeMode",
                 )
-            elif self.altitude_mode in (
+            elif self.altitude_mode in {
                 AltitudeMode.clamp_to_sea_floor,
                 AltitudeMode.relative_to_sea_floor,
-            ):
+            }:
                 altitude_mode = config.etree.SubElement(  # type: ignore[attr-defined]
                     element,
                     f"{self.name_spaces['gx']}altitudeMode",