diff --git a/cinema/models.py b/cinema/models.py
index 7724fd64..56922020 100644
--- a/cinema/models.py
+++ b/cinema/models.py
@@ -89,14 +89,16 @@ def clean(self):
             (self.row, "row", "count_rows"),
             (self.seat, "seat", "count_seats_in_row"),
         ]:
-            count_attrs = getattr(self.movie_session.cinema_hall, cinema_hall_attr_name)
+            count_attrs = getattr(
+                self.movie_session.cinema_hall, cinema_hall_attr_name
+            )
             if not (1 <= ticket_attr_value <= count_attrs):
                 raise ValidationError(
                     {
                         ticket_attr_name: f"{ticket_attr_name} number "
-                                          f"must be in available range: "
-                                          f"(1, {cinema_hall_attr_name}): "
-                                          f"(1, {count_attrs})"
+                        f"must be in available range: "
+                        f"(1, {cinema_hall_attr_name}): "
+                        f"(1, {count_attrs})"
                     }
                 )
 
diff --git a/cinema/serializers.py b/cinema/serializers.py
index 8923dc4e..a929eab6 100644
--- a/cinema/serializers.py
+++ b/cinema/serializers.py
@@ -46,7 +46,10 @@ class MovieDetailSerializer(MovieSerializer):
 
 class MovieSessionSerializer(serializers.ModelSerializer):
     movie = serializers.PrimaryKeyRelatedField(queryset=Movie.objects.all())
-    cinema_hall = serializers.PrimaryKeyRelatedField(queryset=CinemaHall.objects.all())
+    cinema_hall = (serializers.
+                   PrimaryKeyRelatedField
+                   (queryset=CinemaHall.objects.all()))
+
     class Meta:
         model = MovieSession
         fields = ("show_time", "movie", "cinema_hall")
diff --git a/cinema/urls.py b/cinema/urls.py
index 581af4f2..f37fdd7b 100644
--- a/cinema/urls.py
+++ b/cinema/urls.py
@@ -14,10 +14,14 @@
 router.register("genres", GenreViewSet)
 router.register("actors", ActorViewSet)
 router.register("movies", MovieViewSet, basename="movie")
-router.register("movie_sessions", MovieSessionViewSet, basename="movie_session")
+router.register(
+    "movie_sessions",
+    MovieSessionViewSet,
+    basename="movie_session"
+)
 
 urlpatterns = [
     path("", include(router.urls))
 ]
 
-app_name = "cinema"
\ No newline at end of file
+app_name = "cinema"