diff --git a/scripts/lib/upgrade-zulip-stage-2 b/scripts/lib/upgrade-zulip-stage-2
index 8d3d972506..bebf2708ad 100755
--- a/scripts/lib/upgrade-zulip-stage-2
+++ b/scripts/lib/upgrade-zulip-stage-2
@@ -124,7 +124,7 @@ rabbitmq_dist_listen = listening_publicly(25672)
 # Check the erlang magic cookie size
 cookie_size: Optional[int] = None
 if os.path.exists("/var/lib/rabbitmq/.erlang.cookie"):
-    with open("/var/lib/rabbitmq/.erlang.cookie", "r") as cookie_fh:
+    with open("/var/lib/rabbitmq/.erlang.cookie") as cookie_fh:
         cookie_size = len(cookie_fh.readline())
 else:
     logging.info("No RabbitMQ erlang cookie found, not auditing RabbitMQ security.")
diff --git a/zerver/lib/actions.py b/zerver/lib/actions.py
index 5e6d0a4164..dcf3a52a04 100644
--- a/zerver/lib/actions.py
+++ b/zerver/lib/actions.py
@@ -6584,7 +6584,7 @@ def maybe_send_resolve_topic_notifications(
     # Compute the users who either sent or reacted to messages that
     # were moved via the "resolve topic' action. Only those users
     # should be eligible for this message being managed as unread.
-    affected_participant_ids = (set(message.sender_id for message in changed_messages)) | set(
+    affected_participant_ids = {message.sender_id for message in changed_messages} | set(
         Reaction.objects.filter(message__in=changed_messages).values_list(
             "user_profile_id", flat=True
         )
diff --git a/zerver/migrations/0375_invalid_characters_in_stream_names.py b/zerver/migrations/0375_invalid_characters_in_stream_names.py
index 129ed40e21..3d2803eec1 100644
--- a/zerver/migrations/0375_invalid_characters_in_stream_names.py
+++ b/zerver/migrations/0375_invalid_characters_in_stream_names.py
@@ -6,12 +6,12 @@ from django.db.migrations.state import StateApps
 
 # There are 66 Unicode non-characters; see
 # https://www.unicode.org/faq/private_use.html#nonchar4
-unicode_non_chars = set(
+unicode_non_chars = {
     chr(x)
     for x in list(range(0xFDD0, 0xFDF0))  # FDD0 through FDEF, inclusive
     + list(range(0xFFFE, 0x110000, 0x10000))  # 0xFFFE, 0x1FFFE, ... 0x10FFFE inclusive
     + list(range(0xFFFF, 0x110000, 0x10000))  # 0xFFFF, 0x1FFFF, ... 0x10FFFF inclusive
-)
+}
 
 
 def character_is_printable(character: str) -> bool:
@@ -31,7 +31,7 @@ def fix_stream_names(apps: StateApps, schema_editor: DatabaseSchemaEditor) -> No
     for realm_id in realm_ids:
         print(f"Processing realm {realm_id}")
         realm_stream_dicts = Stream.objects.filter(realm_id=realm_id).values("id", "name")
-        occupied_stream_names = set(stream_dict["name"] for stream_dict in realm_stream_dicts)
+        occupied_stream_names = {stream_dict["name"] for stream_dict in realm_stream_dicts}
 
         for stream_dict in realm_stream_dicts:
             stream_name = stream_dict["name"]
diff --git a/zerver/tests/test_message_flags.py b/zerver/tests/test_message_flags.py
index 5bb2de62f2..7bbf4c8b48 100644
--- a/zerver/tests/test_message_flags.py
+++ b/zerver/tests/test_message_flags.py
@@ -1552,7 +1552,7 @@ class MarkUnreadTest(ZulipTestCase):
         self.assert_json_success(result)
         event = events[0]["event"]
         self.assertEqual(event["messages"], messages_to_unread)
-        unread_message_ids = set(str(message_id) for message_id in messages_to_unread)
+        unread_message_ids = {str(message_id) for message_id in messages_to_unread}
         self.assertSetEqual(set(event["message_details"].keys()), unread_message_ids)
         for message_id in event["message_details"]:
             self.assertEqual(
@@ -1625,7 +1625,7 @@ class MarkUnreadTest(ZulipTestCase):
         self.assert_json_success(result)
         event = events[0]["event"]
         self.assertEqual(event["messages"], messages_to_unread)
-        unread_message_ids = set(str(message_id) for message_id in messages_to_unread)
+        unread_message_ids = {str(message_id) for message_id in messages_to_unread}
         self.assertSetEqual(set(event["message_details"].keys()), unread_message_ids)
         for message_id in event["message_details"]:
             self.assertEqual(
@@ -1698,7 +1698,7 @@ class MarkUnreadTest(ZulipTestCase):
         self.assert_json_success(result)
         event = events[0]["event"]
         self.assertEqual(event["messages"], messages_to_unread)
-        unread_message_ids = set(str(message_id) for message_id in messages_to_unread)
+        unread_message_ids = {str(message_id) for message_id in messages_to_unread}
         self.assertSetEqual(set(event["message_details"].keys()), unread_message_ids)
         for message_id in event["message_details"]:
             self.assertEqual(
@@ -1768,7 +1768,7 @@ class MarkUnreadTest(ZulipTestCase):
         self.assert_json_success(result)
         event = events[0]["event"]
         self.assertEqual(event["messages"], messages_to_unread)
-        unread_message_ids = set(str(message_id) for message_id in messages_to_unread)
+        unread_message_ids = {str(message_id) for message_id in messages_to_unread}
         self.assertSetEqual(set(event["message_details"].keys()), unread_message_ids)
         for message_id in event["message_details"]:
             self.assertEqual(
@@ -1838,7 +1838,7 @@ class MarkUnreadTest(ZulipTestCase):
         self.assert_json_success(result)
         event = events[0]["event"]
         self.assertEqual(event["messages"], messages_to_unread)
-        unread_message_ids = set(str(message_id) for message_id in messages_to_unread)
+        unread_message_ids = {str(message_id) for message_id in messages_to_unread}
         self.assertSetEqual(set(event["message_details"].keys()), unread_message_ids)
         for message_id in event["message_details"]:
             self.assertEqual(
@@ -1909,7 +1909,7 @@ class MarkUnreadTest(ZulipTestCase):
         self.assert_json_success(result)
         event = events[0]["event"]
         self.assertEqual(event["messages"], messages_to_unread)
-        unread_message_ids = set(str(message_id) for message_id in messages_to_unread)
+        unread_message_ids = {str(message_id) for message_id in messages_to_unread}
         self.assertSetEqual(set(event["message_details"].keys()), unread_message_ids)
         for message_id in event["message_details"]:
             self.assertNotIn("mentioned", event["message_details"][message_id]),
@@ -1975,7 +1975,7 @@ class MarkUnreadTest(ZulipTestCase):
         self.assert_json_success(result)
         event = events[0]["event"]
         self.assertEqual(event["messages"], messages_to_unread)
-        unread_message_ids = set(str(message_id) for message_id in messages_to_unread)
+        unread_message_ids = {str(message_id) for message_id in messages_to_unread}
         self.assertSetEqual(set(event["message_details"].keys()), unread_message_ids)
         for message_id in event["message_details"]:
             self.assertEqual(event["message_details"][message_id]["mentioned"], True),