diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 0717acaab..eff20805f 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -894,6 +894,7 @@ class AlphabeticFieldValidator:
         if not re.match(r'^[A-Za-z ]*$', value):
             raise ValueError("This field must contain only alphabetic characters and spaces.")
 
+
 class AlphanumericFieldValidator:
     """
     Custom validator to ensure the field contains only alphanumeric characters (letters and numbers).
@@ -906,6 +907,7 @@ class AlphanumericFieldValidator:
         if not re.match(r'^[A-Za-z0-9]*$', value):
             raise ValueError("This field must contain only alphanumeric characters (letters and numbers).")
 
+
 class CustomLengthValidator:
     """
     Custom validator to ensure the length of a string is within specified limits.
diff --git a/rest_framework/permissions.py b/rest_framework/permissions.py
index 3c0de3d67..9c9211d8f 100644
--- a/rest_framework/permissions.py
+++ b/rest_framework/permissions.py
@@ -172,6 +172,7 @@ class IsAuthenticatedOrReadOnly(BasePermission):
             request.user.is_authenticated
         )
 
+
 class IsAdminUserOrReadOnly(BasePermission):
     """
     Custom permission to only allow admin users to edit an object.
diff --git a/tests/models.py b/tests/models.py
index 1c5d58c1d..90be1d7b6 100644
--- a/tests/models.py
+++ b/tests/models.py
@@ -157,4 +157,4 @@ class OwnershipTestModel(models.Model):
     title = models.CharField(max_length=100)
 
     def __str__(self):
-        return self.title
\ No newline at end of file
+        return self.title
diff --git a/tests/test_fields.py b/tests/test_fields.py
index 089772b8a..a278015a2 100644
--- a/tests/test_fields.py
+++ b/tests/test_fields.py
@@ -1141,6 +1141,7 @@ class TestAlphanumericField:
                 validator(value)
             assert str(excinfo.value) == "This field must be a string."
 
+
 class TestCustomLengthField:
     """
     Valid and invalid values for `CustomLengthValidator`.
diff --git a/tests/test_permissions.py b/tests/test_permissions.py
index 417dbd3c8..e1b17d0ac 100644
--- a/tests/test_permissions.py
+++ b/tests/test_permissions.py
@@ -819,4 +819,4 @@ class PermissionTests(TestCase):
         self.assertTrue(permission.has_object_permission(request, None, obj))
 
         request.user = self.admin_user
-        self.assertTrue(permission.has_object_permission(request, None, obj))
\ No newline at end of file
+        self.assertTrue(permission.has_object_permission(request, None, obj))
diff --git a/tests/test_status.py b/tests/test_status.py
index 7fbe1b522..4d7aeb90a 100644
--- a/tests/test_status.py
+++ b/tests/test_status.py
@@ -1,8 +1,7 @@
 from django.test import TestCase
 
 from rest_framework.status import (
-    is_client_error, is_informational, is_redirect, is_server_error,
-    is_success
+    is_client_error, is_informational, is_redirect, is_server_error, is_success
 )
 
 
diff --git a/tests/test_validators.py b/tests/test_validators.py
index 5ea0542c4..4bb8658d5 100644
--- a/tests/test_validators.py
+++ b/tests/test_validators.py
@@ -10,8 +10,7 @@ from django.test import TestCase
 from rest_framework import serializers
 from rest_framework.exceptions import ValidationError
 from rest_framework.validators import (
-    BaseUniqueForValidator, UniqueTogetherValidator, UniqueValidator,
-    qs_exists
+    BaseUniqueForValidator, UniqueTogetherValidator, UniqueValidator, qs_exists
 )