diff --git a/oauthenticator/generic.py b/oauthenticator/generic.py
index c11b5eb7..c2e4e36c 100644
--- a/oauthenticator/generic.py
+++ b/oauthenticator/generic.py
@@ -3,12 +3,11 @@
 """
 
 import os
-from functools import reduce
 
 from jupyterhub.auth import LocalAuthenticator
 from jupyterhub.traitlets import Callable
 from tornado.httpclient import AsyncHTTPClient
-from traitlets import Bool, Dict, Set, Unicode, Union, default, observe
+from traitlets import Bool, Dict, Unicode, Union, default, observe
 
 from .oauth2 import OAuthenticator
 
@@ -37,9 +36,13 @@ def _login_service_default(self):
     def _claim_groups_key_changed(self, change):
         if callable(change.new):
             # Automatically wrap the claim_gorups_key call so it gets what it thinks it should get
-            self.auth_model_groups_key = lambda auth_model: self.claim_groups_key(auth_model["auth_state"][self.user_auth_state_key])
+            self.auth_model_groups_key = lambda auth_model: self.claim_groups_key(
+                auth_model["auth_state"][self.user_auth_state_key]
+            )
         else:
-            self.auth_model_groups_key = f"auth_state.{self.user_auth_state_key}.{self.claim_groups_key}"
+            self.auth_model_groups_key = (
+                f"auth_state.{self.user_auth_state_key}.{self.claim_groups_key}"
+            )
 
     @default("http_client")
     def _default_http_client(self):
diff --git a/oauthenticator/oauth2.py b/oauthenticator/oauth2.py
index c6846ef9..cde8e95e 100644
--- a/oauthenticator/oauth2.py
+++ b/oauthenticator/oauth2.py
@@ -7,8 +7,8 @@
 import base64
 import json
 import os
-from functools import reduce
 import uuid
+from functools import reduce
 from urllib.parse import quote, urlencode, urlparse, urlunparse
 
 import jwt
@@ -21,7 +21,18 @@
 from tornado.httpclient import AsyncHTTPClient, HTTPClientError, HTTPRequest
 from tornado.httputil import url_concat
 from tornado.log import app_log
-from traitlets import Any, Bool, Callable, Dict, List, Unicode, Union, default, Set, validate
+from traitlets import (
+    Any,
+    Bool,
+    Callable,
+    Dict,
+    List,
+    Set,
+    Unicode,
+    Union,
+    default,
+    validate,
+)
 
 
 def guess_callback_uri(protocol, host, hub_server_url):
@@ -1047,7 +1058,9 @@ def get_user_groups(self, auth_model: dict):
         if callable(self.claim_groups_key):
             return set(self.auth_model_groups_key(auth_model))
         try:
-            return set(reduce(dict.get, self.auth_model_groups_key.split("."), auth_model))
+            return set(
+                reduce(dict.get, self.auth_model_groups_key.split("."), auth_model)
+            )
         except TypeError:
             self.log.error(
                 f"The auth_model_groups_key {self.auth_model_groups_key} does not exist in the auth_model. Available keys are: {auth_model.keys()}"