diff --git a/sceptre/cli/update.py b/sceptre/cli/update.py
index 155e135a3..419ffc66a 100644
--- a/sceptre/cli/update.py
+++ b/sceptre/cli/update.py
@@ -66,7 +66,10 @@ def update_command(
 
             for status in list(statuses.values()):
                 # Exit if change set fails to create
-                if status not in (StackChangeSetStatus.READY, StackChangeSetStatus.NO_CHANGES):
+                if status not in (
+                    StackChangeSetStatus.READY,
+                    StackChangeSetStatus.NO_CHANGES,
+                ):
                     write("Failed to create change set", context.output_format)
                     exit(1)
 
diff --git a/sceptre/plan/actions.py b/sceptre/plan/actions.py
index 2126f82fb..478c16df1 100644
--- a/sceptre/plan/actions.py
+++ b/sceptre/plan/actions.py
@@ -925,18 +925,17 @@ def _get_cs_status(self, change_set_name):
         ] and cs_exec_status in ["UNAVAILABLE", "AVAILABLE"]:
             return StackChangeSetStatus.PENDING
         elif (
-                cs_status == "FAILED" and
-                cs_reason is not None and
-                self.change_set_creation_failed_due_to_no_changes(cs_reason)
+            cs_status == "FAILED"
+            and cs_reason is not None
+            and self.change_set_creation_failed_due_to_no_changes(cs_reason)
         ):
             return StackChangeSetStatus.NO_CHANGES
-        elif (
-                cs_status in ["DELETE_COMPLETE", "FAILED"] or
-                cs_exec_status in [
-                    "EXECUTE_IN_PROGRESS", "EXECUTE_COMPLETE",
-                    "EXECUTE_FAILED", "OBSOLETE"
-                ]
-        ):
+        elif cs_status in ["DELETE_COMPLETE", "FAILED"] or cs_exec_status in [
+            "EXECUTE_IN_PROGRESS",
+            "EXECUTE_COMPLETE",
+            "EXECUTE_FAILED",
+            "OBSOLETE",
+        ]:
             return StackChangeSetStatus.DEFUNCT
         else:  # pragma: no cover
             raise Exception("This else should not be reachable.")
diff --git a/tests/test_actions.py b/tests/test_actions.py
index 379f3967e..c3c5a007d 100644
--- a/tests/test_actions.py
+++ b/tests/test_actions.py
@@ -1169,12 +1169,10 @@ def test_get_cs_status_handles_all_statuses(self, mock_describe_change_set):
         mock_describe_change_set.return_value = {
             "Status": "FAILED",
             "StatusReason": "The submitted information didn't contain changes. "
-                            "Submit different information to create a change set.",
-            "ExecutionStatus": "UNAVAILABLE"
+            "Submit different information to create a change set.",
+            "ExecutionStatus": "UNAVAILABLE",
         }
-        response = self.actions._get_cs_status(
-            sentinel.change_set_name
-        )
+        response = self.actions._get_cs_status(sentinel.change_set_name)
         assert response == scss.NO_CHANGES
 
         for status in return_values["Status"]:
diff --git a/tests/test_cli/test_cli_commands.py b/tests/test_cli/test_cli_commands.py
index 439760314..08403e05e 100644
--- a/tests/test_cli/test_cli_commands.py
+++ b/tests/test_cli/test_cli_commands.py
@@ -515,7 +515,8 @@ def test_stack_commands(self, command, success, yes_flag, exit_code):
         assert result.exit_code == exit_code
 
     @pytest.mark.parametrize(
-        "change_set_status,yes_flag,exit_code,verbose_flag", [
+        "change_set_status,yes_flag,exit_code,verbose_flag",
+        [
             (StackChangeSetStatus.READY, True, 0, True),
             (StackChangeSetStatus.READY, True, 0, False),
             (StackChangeSetStatus.READY, False, 0, True),
@@ -528,9 +529,11 @@ def test_stack_commands(self, command, success, yes_flag, exit_code):
             (StackChangeSetStatus.DEFUNCT, False, 1, False),
             (StackChangeSetStatus.DEFUNCT, True, 1, False),
             (StackChangeSetStatus.DEFUNCT, False, 1, True),
-        ]
+        ],
     )
-    def test_update_with_change_set(self, change_set_status, yes_flag, exit_code, verbose_flag):
+    def test_update_with_change_set(
+        self, change_set_status, yes_flag, exit_code, verbose_flag
+    ):
         create_command = self.mock_stack_actions.create_change_set
         wait_command = self.mock_stack_actions.wait_for_cs_completion
         execute_command = self.mock_stack_actions.execute_change_set
@@ -556,10 +559,10 @@ def test_update_with_change_set(self, change_set_status, yes_flag, exit_code, ve
                         "Replacement": "Replacement",
                         "ResourceType": "ResourceType",
                         "Scope": "Scope",
-                        "VerboseProperty": "VerboseProperty"
+                        "VerboseProperty": "VerboseProperty",
                     }
                 }
-            ]
+            ],
         }
 
         if not verbose_flag:
@@ -581,14 +584,14 @@ def test_update_with_change_set(self, change_set_status, yes_flag, exit_code, ve
         result = self.runner.invoke(cli, **kwargs)
 
         change_set_name = create_command.call_args[0][0]
-        assert 'change-set' in change_set_name
+        assert "change-set" in change_set_name
 
-        assert wait_command.called_with(change_set_name)
-        assert delete_command.called_with(change_set_name)
+        wait_command.assert_called_once_with(change_set_name)
+        delete_command.assert_called_once_with(change_set_name)
 
         if change_set_status == StackChangeSetStatus.READY:
-            assert execute_command.called_with(change_set_name)
-            assert describe_command.called_with(change_set_name)
+            execute_command.assert_called_once_with(change_set_name)
+            describe_command.assert_called_once_with(change_set_name)
             output = result.output.splitlines()[0]
             assert yaml.safe_load(output) == response
 
@@ -601,7 +604,8 @@ def test_update_with_change_set(self, change_set_status, yes_flag, exit_code, ve
         assert result.exit_code == exit_code
 
     @pytest.mark.parametrize(
-        "command, ignore_dependencies", [
+        "command, ignore_dependencies",
+        [
             ("create", True),
             ("create", False),
             ("delete", True),