diff --git a/moto/iot/models.py b/moto/iot/models.py
index 0ef53bbb5..c36bb985f 100644
--- a/moto/iot/models.py
+++ b/moto/iot/models.py
@@ -281,14 +281,15 @@ class IoTBackend(BaseBackend):
     def list_things(self, attribute_name, attribute_value, thing_type_name, max_results, token):
         all_things = [_.to_dict() for _ in self.things.values()]
         if attribute_name is not None and thing_type_name is not None:
-            filtered_things = list(
-                filter(
-                    lambda elem: attribute_name in elem["attributes"] and elem["attributes"][
-                        attribute_name] == attribute_value and "thingTypeName" in elem and elem[
-                                     "thingTypeName"] == thing_type_name, all_things))
+            filtered_things = list(filter(lambda elem:
+                                          attribute_name in elem["attributes"] and
+                                          elem["attributes"][attribute_name] == attribute_value and
+                                          "thingTypeName" in elem and
+                                          elem["thingTypeName"] == thing_type_name, all_things))
         elif attribute_name is not None and thing_type_name is None:
-            filtered_things = list(filter(lambda elem: attribute_name in elem["attributes"] and elem["attributes"][
-                attribute_name] == attribute_value, all_things))
+            filtered_things = list(filter(lambda elem:
+                                          attribute_name in elem["attributes"] and
+                                          elem["attributes"][attribute_name] == attribute_value, all_things))
         elif attribute_name is None and thing_type_name is not None:
             filtered_things = list(
                 filter(lambda elem: "thingTypeName" in elem and elem["thingTypeName"] == thing_type_name, all_things))