Apply suggestions from code review

Co-authored-by: Carol Willing <carolcode@willingconsulting.com>

jupyterhub/apihandlers/users.py

@@ -210,7 +210,7 @@ class UserListAPIHandler(APIHandler):
             except Exception as e:
                 self.log.error("Failed to create user: %s" % name, exc_info=True)
                 self.users.delete(user)
-                raise web.HTTPError(400, f"Failed to create user {name}: {str(e)}")
+                raise web.HTTPError(400, f"Failed to create user {name}: {e}")
             else:
                 created.append(user)
 

jupyterhub/handlers/base.py

@@ -623,7 +623,7 @@ class BaseHandler(RequestHandler):
         if (next_url + '/').startswith(
             (
                 f'{self.request.protocol}://{self.request.host}/',
-                '//%s/' % self.request.host,
+                f'//{self.request.host}/',
             )
         ) or (
             self.subdomain_host

jupyterhub/objects.py

@@ -148,7 +148,9 @@ class Server(HasTraits):
     def host(self):
         if self.connect_url:
             parsed = urlparse(self.connect_url)
-            return f"{parsed.scheme}://{parsed.netloc}"
+            proto = parsed.scheme
+            host = parsed.netloc
+            return f"{proto}://{host}"
 
         if ':' in self._connect_ip:
             fmt = "{proto}://[{ip}]:{port}"

jupyterhub/orm.py

@@ -1039,8 +1039,6 @@ def get_class(resource_name):
     }
     if resource_name not in class_dict:
         raise ValueError(
-            "Kind must be one of {}, not {}".format(
-                ", ".join(class_dict), resource_name
-            )
+            f'Kind must be one of {", ".join(class_dict)}, not {resource_name}'
         )
     return class_dict[resource_name]