Partially Use f string (#10218)

* flynt. trial 1.

* Trial 1.

* Addressed code review.

python/ray/monitor.py

@@ -133,8 +133,7 @@ class Monitor:
                                          available_resources, resource_load)
             else:
                 logger.warning(
-                    "Monitor: "
-                    "could not find ip for client {}".format(client_id))
+                    f"Monitor: could not find ip for client {client_id}")
             self.handle_resource_demands(message.resource_load_by_shape)
 
     def xray_job_notification_handler(self, unused_channel, data):
@@ -366,8 +365,8 @@ if __name__ == "__main__":
         redis_client = ray.services.create_redis_client(
             args.redis_address, password=args.redis_password)
         traceback_str = ray.utils.format_error_message(traceback.format_exc())
-        message = "The monitor failed with the following error:\n{}".format(
-            traceback_str)
+        message = ("The monitor failed with the "
+                   f"following error:\n{traceback_str}")
         ray.utils.push_error_to_driver_through_redis(
             redis_client, ray_constants.MONITOR_DIED_ERROR, message)
         raise e