Remove (object) from class declarations. (#6658)

python/ray/actor.py

@@ -27,7 +27,7 @@ def method(*args, **kwargs):
     .. code-block:: python
 
         @ray.remote
-        class Foo(object):
+        class Foo:
             @ray.method(num_return_vals=2)
             def bar(self):
                 return 1, 2
@@ -54,7 +54,7 @@ def method(*args, **kwargs):
 
 # Create objects to wrap method invocations. This is done so that we can
 # invoke methods with actor.method.remote() instead of actor.method().
-class ActorMethod(object):
+class ActorMethod:
     """A class used to invoke an actor method.
 
     Note: This class only keeps a weak ref to the actor, unless it has been
@@ -143,7 +143,7 @@ class ActorMethod(object):
             hardref=True)
 
 
-class ActorClassMetadata(object):
+class ActorClassMetadata:
     """Metadata for an actor class.
 
     Attributes:
@@ -234,7 +234,7 @@ class ActorClassMetadata(object):
                     method.__ray_invocation_decorator__)
 
 
-class ActorClass(object):
+class ActorClass:
     """An actor class.
 
     This is a decorated class. It can be used to create actors.
@@ -339,7 +339,7 @@ class ActorClass(object):
 
         actor_cls = self
 
-        class ActorOptionWrapper(object):
+        class ActorOptionWrapper:
             def remote(self, *args, **kwargs):
                 return actor_cls._remote(args=args, kwargs=kwargs, **options)
 
@@ -518,7 +518,7 @@ class ActorClass(object):
         return actor_handle
 
 
-class ActorHandle(object):
+class ActorHandle:
     """A handle to an actor.
 
     The fields in this class are prefixed with _ray_ to hide them from the user

python/ray/autoscaler/autoscaler.py

@@ -156,7 +156,7 @@ CLUSTER_CONFIG_SCHEMA = {
 }
 
 
-class LoadMetrics(object):
+class LoadMetrics:
     """Container for cluster load metrics.
 
     Metrics here are updated from raylet heartbeats. The autoscaler
@@ -355,7 +355,7 @@ class NodeLauncher(threading.Thread):
         logger.info(prefix + " {}".format(statement))
 
 
-class ConcurrentCounter(object):
+class ConcurrentCounter:
     def __init__(self):
         self._value = 0
         self._lock = threading.Lock()
@@ -377,7 +377,7 @@ class ConcurrentCounter(object):
             return self._value
 
 
-class StandardAutoscaler(object):
+class StandardAutoscaler:
     """The autoscaling control loop for a Ray cluster.
 
     There are two ways to start an autoscaling cluster: manually by running

python/ray/autoscaler/local/node_provider.py

@@ -19,7 +19,7 @@ filelock_logger = logging.getLogger("filelock")
 filelock_logger.setLevel(logging.WARNING)
 
 
-class ClusterState(object):
+class ClusterState:
     def __init__(self, lock_path, save_path, provider_config):
         self.lock = RLock()
         self.file_lock = FileLock(lock_path)

python/ray/autoscaler/log_timer.py

@@ -8,7 +8,7 @@ import logging
 logger = logging.getLogger(__name__)
 
 
-class LogTimer(object):
+class LogTimer:
     def __init__(self, message):
         self._message = message
 

python/ray/autoscaler/node_provider.py

@@ -129,7 +129,7 @@ def get_default_config(provider_config):
     return defaults
 
 
-class NodeProvider(object):
+class NodeProvider:
     """Interface for getting and returning nodes from a Cloud.
 
     NodeProviders are namespaced by the `cluster_name` parameter; they only

python/ray/autoscaler/updater.py

@@ -37,7 +37,7 @@ def with_interactive(cmd):
     return ["bash", "--login", "-c", "-i", quote(force_interactive + cmd)]
 
 
-class KubernetesCommandRunner(object):
+class KubernetesCommandRunner:
     def __init__(self, log_prefix, namespace, node_id, auth_config,
                  process_runner):
 
@@ -149,7 +149,7 @@ class KubernetesCommandRunner(object):
                                             self.node_id)
 
 
-class SSHCommandRunner(object):
+class SSHCommandRunner:
     def __init__(self, log_prefix, node_id, provider, auth_config,
                  cluster_name, process_runner, use_internal_ip):
 
@@ -284,7 +284,7 @@ class SSHCommandRunner(object):
                                           self.ssh_ip)
 
 
-class NodeUpdater(object):
+class NodeUpdater:
     """A process for syncing files and running init commands on a node."""
 
     def __init__(self,

python/ray/cluster_utils.py

@@ -13,7 +13,7 @@ from ray import ray_constants
 logger = logging.getLogger(__name__)
 
 
-class Cluster(object):
+class Cluster:
     def __init__(self,
                  initialize_head=False,
                  connect=False,

python/ray/dashboard/dashboard.py

@@ -72,7 +72,7 @@ def format_reply(reply):
             format_reply(item)
 
 
-class Dashboard(object):
+class Dashboard:
     """A dashboard process for monitoring Ray nodes.
 
     This dashboard is made up of a REST API which collates data published by

python/ray/experimental/actor_pool.py

@@ -5,7 +5,7 @@ from __future__ import print_function
 import ray
 
 
-class ActorPool(object):
+class ActorPool:
     """Utility class to operate on a fixed pool of actors.
 
     Arguments:

python/ray/experimental/array/distributed/core.py

@@ -9,7 +9,7 @@ import ray
 BLOCK_SIZE = 10
 
 
-class DistArray(object):
+class DistArray:
     def __init__(self, shape, objectids=None):
         self.shape = shape
         self.ndim = len(shape)

python/ray/experimental/async_api.py

@@ -15,7 +15,7 @@ transport = None
 protocol = None
 
 
-class _ThreadSafeProxy(object):
+class _ThreadSafeProxy:
     """This class is used to create a thread-safe proxy for a given object.
         Every method call will be guarded with a lock.
 

python/ray/experimental/gcs_flush_policy.py

@@ -9,7 +9,7 @@ import ray
 import ray.cloudpickle as pickle
 
 
-class GcsFlushPolicy(object):
+class GcsFlushPolicy:
     """Experimental: a policy to control GCS flushing.
 
     Used by Monitor to enable automatic control of memory usage.

python/ray/experimental/multiprocessing/pool.py

@@ -105,7 +105,7 @@ class ResultThread(threading.Thread):
             raise TimeoutError
 
 
-class AsyncResult(object):
+class AsyncResult:
     """An asynchronous interface to task results.
 
     This should not be constructed directly.
@@ -168,7 +168,7 @@ class AsyncResult(object):
         return not self._result_thread.got_error()
 
 
-class IMapIterator(object):
+class IMapIterator:
     """Base class for OrderedIMapIterator and UnorderedIMapIterator."""
 
     def __init__(self, pool, func, iterable, chunksize=None):
@@ -273,7 +273,7 @@ class UnorderedIMapIterator(IMapIterator):
 
 
 @ray.remote
-class PoolActor(object):
+class PoolActor:
     """Actor used to process tasks submitted to a Pool."""
 
     def __init__(self, initializer=None, initargs=None):
@@ -298,7 +298,7 @@ class PoolActor(object):
 
 
 # https://docs.python.org/3/library/multiprocessing.html#module-multiprocessing.pool
-class Pool(object):
+class Pool:
     """A pool of actor processes that is used to process tasks in parallel.
 
     Args:

python/ray/experimental/no_return.py

@@ -3,7 +3,7 @@ from __future__ import division
 from __future__ import print_function
 
 
-class NoReturn(object):
+class NoReturn:
     """Do not store the return value in the object store.
 
     If a task returns this object, then Ray will not store this object in the

python/ray/experimental/queue.py

@@ -16,7 +16,7 @@ class Full(Exception):
     pass
 
 
-class Queue(object):
+class Queue:
     """Queue implementation on Ray.
 
     Args:
@@ -132,7 +132,7 @@ class Queue(object):
 
 
 @ray.remote
-class _QueueActor(object):
+class _QueueActor:
     def __init__(self, maxsize):
         self.maxsize = maxsize
         self._init(maxsize)

python/ray/experimental/serve/tests/test_metric.py

@@ -8,7 +8,7 @@ from ray.experimental.serve.metric import MetricMonitor
 @pytest.fixture(scope="session")
 def start_target_actor(ray_instance):
     @ray.remote
-    class Target(object):
+    class Target:
         def __init__(self):
             self.counter_value = 0
 

python/ray/experimental/sgd/pytorch/pytorch_runner.py

@@ -17,7 +17,7 @@ from ray.experimental.sgd import utils
 logger = logging.getLogger(__name__)
 
 
-class PyTorchRunner(object):
+class PyTorchRunner:
     """Manages a PyTorch model for training."""
 
     def __init__(self,

python/ray/experimental/sgd/pytorch/pytorch_trainer.py

@@ -21,7 +21,7 @@ from ray.experimental.sgd.pytorch.pytorch_runner import PyTorchRunner
 logger = logging.getLogger(__name__)
 
 
-class PyTorchTrainer(object):
+class PyTorchTrainer:
     """Train a PyTorch model using distributed PyTorch.
 
     Launches a set of actors which connect via distributed PyTorch and

python/ray/experimental/sgd/pytorch/utils.py

@@ -108,7 +108,7 @@ def validate(model, val_iterator, criterion, config):
     return stats
 
 
-class AverageMeter(object):
+class AverageMeter:
     """Computes and stores the average and current value."""
 
     def __init__(self):

python/ray/experimental/sgd/tf/tf_runner.py

@@ -20,7 +20,7 @@ def _try_import_strategy():
     return tf.distribute.experimental.MultiWorkerMirroredStrategy
 
 
-class TFRunner(object):
+class TFRunner:
     """Manages a TensorFlow model for training."""
 
     def __init__(self, model_creator, data_creator, config=None,

python/ray/experimental/sgd/tf/tf_trainer.py

@@ -16,7 +16,7 @@ from ray.experimental.sgd.tf.tf_runner import TFRunner
 logger = logging.getLogger(__name__)
 
 
-class TFTrainer(object):
+class TFTrainer:
     def __init__(self,
                  model_creator,
                  data_creator,

python/ray/experimental/sgd/utils.py

@@ -8,7 +8,7 @@ import socket
 import time
 
 
-class TimerStat(object):
+class TimerStat:
     """A running stat for conveniently logging the duration of a code block.
 
     Note that this class is *not* thread-safe.
@@ -108,7 +108,7 @@ def find_free_port():
         return s.getsockname()[1]
 
 
-class AverageMeter(object):
+class AverageMeter:
     """Computes and stores the average and current value."""
 
     def __init__(self):

python/ray/experimental/signal.py

@@ -18,7 +18,7 @@ ACTOR_DIED_STR = "ACTOR_DIED_SIGNAL"
 logger = logging.getLogger(__name__)
 
 
-class Signal(object):
+class Signal:
     """Base class for Ray signals."""
     pass
 

python/ray/experimental/tf_utils.py

@@ -22,7 +22,7 @@ def unflatten(vector, shapes):
     return arrays
 
 
-class TensorFlowVariables(object):
+class TensorFlowVariables:
     """A class used to set and get weights for Tensorflow networks.
 
     Attributes:

python/ray/function_manager.py

@@ -39,7 +39,7 @@ FunctionExecutionInfo = namedtuple("FunctionExecutionInfo",
 logger = logging.getLogger(__name__)
 
 
-class FunctionDescriptor(object):
+class FunctionDescriptor:
     """A class used to describe a python function.
 
     Attributes:
@@ -259,7 +259,7 @@ class FunctionDescriptor(object):
         return len(self._class_name) > 0
 
 
-class FunctionActorManager(object):
+class FunctionActorManager:
     """A class used to export/load remote functions and actors.
 
     Attributes:
@@ -658,7 +658,7 @@ class FunctionActorManager(object):
                     class_name))
 
     def _create_fake_actor_class(self, actor_class_name, actor_method_names):
-        class TemporaryActor(object):
+        class TemporaryActor:
             pass
 
         def temporary_actor_method(*args, **kwargs):

python/ray/import_thread.py

@@ -19,7 +19,7 @@ import logging
 logger = logging.getLogger(__name__)
 
 
-class ImportThread(object):
+class ImportThread:
     """A thread used to import exports from the driver or other workers.
 
     Note: The driver also has an import thread, which is used only to import

python/ray/local_mode_manager.py

@@ -35,7 +35,7 @@ class LocalModeObjectID(ObjectID):
         return new
 
 
-class LocalModeManager(object):
+class LocalModeManager:
     """Used to emulate remote operations when running in local mode."""
 
     def __init__(self):

python/ray/log_monitor.py

@@ -22,7 +22,7 @@ import ray.utils
 logger = logging.getLogger(__name__)
 
 
-class LogFileInfo(object):
+class LogFileInfo:
     def __init__(self,
                  filename=None,
                  size_when_last_opened=None,
@@ -37,7 +37,7 @@ class LogFileInfo(object):
         self.worker_pid = None
 
 
-class LogMonitor(object):
+class LogMonitor:
     """A monitor process for monitoring Ray log files.
 
     This class mantains a list of open files and a list of closed log files. We

python/ray/memory_monitor.py

@@ -65,7 +65,7 @@ class RayOutOfMemoryError(Exception):
                 "these memory limits to a lower value.")
 
 
-class MemoryMonitor(object):
+class MemoryMonitor:
     """Helper class for raising errors on low memory.
 
     This presents a much cleaner error message to users than what would happen

python/ray/monitor.py

@@ -23,7 +23,7 @@ from ray.utils import (binary_to_hex, binary_to_object_id, binary_to_task_id,
 logger = logging.getLogger(__name__)
 
 
-class Monitor(object):
+class Monitor:
     """A monitor for Ray processes.
 
     The monitor is in charge of cleaning up the tables in the global state

python/ray/node.py

@@ -30,7 +30,7 @@ logger = logging.getLogger(__name__)
 SESSION_LATEST = "session_latest"
 
 
-class Node(object):
+class Node:
     """An encapsulation of the Ray processes on a single node.
 
     This class is responsible for starting Ray processes and killing them,
@@ -882,7 +882,7 @@ class Node(object):
         return not any(self.dead_processes())
 
 
-class LocalNode(object):
+class LocalNode:
     """Imitate the node that manages the processes in local mode."""
 
     def kill_all_processes(self, *args, **kwargs):

python/ray/parameter.py

@@ -10,7 +10,7 @@ from packaging import version
 import ray.ray_constants as ray_constants
 
 
-class RayParams(object):
+class RayParams:
     """A class used to store the parameters used by Ray.
 
     Attributes:

python/ray/profiling.py

@@ -5,7 +5,7 @@ from __future__ import print_function
 import ray
 
 
-class _NullLogSpan(object):
+class _NullLogSpan:
     """A log span context manager that does nothing"""
 
     def __enter__(self):

python/ray/projects/scripts.py

@@ -147,7 +147,7 @@ def load_project_or_throw():
             "`ray project validate` to inspect the error.")
 
 
-class SessionRunner(object):
+class SessionRunner:
     """Class for setting up a session and executing commands in it."""
 
     def __init__(self, session_name=None):

python/ray/ray_perf.py

@@ -11,7 +11,7 @@ filter_pattern = os.environ.get("TESTS_TO_RUN", "")
 
 
 @ray.remote(num_cpus=0)
-class Actor(object):
+class Actor:
     def small_value(self):
         return b"ok"
 
@@ -23,7 +23,7 @@ class Actor(object):
 
 
 @ray.remote(num_cpus=0)
-class Client(object):
+class Client:
     def __init__(self, servers):
         if not isinstance(servers, list):
             servers = [servers]

python/ray/remote_function.py

@@ -21,7 +21,7 @@ DEFAULT_REMOTE_FUNCTION_NUM_TASK_RETRIES = 3
 logger = logging.getLogger(__name__)
 
 
-class RemoteFunction(object):
+class RemoteFunction:
     """A remote function.
 
     This is a decorated function. It can be used to spawn tasks.
@@ -133,7 +133,7 @@ class RemoteFunction(object):
 
         func_cls = self
 
-        class FuncWrapper(object):
+        class FuncWrapper:
             def remote(self, *args, **kwargs):
                 return func_cls._remote(args=args, kwargs=kwargs, **options)
 

python/ray/reporter.py

@@ -56,7 +56,7 @@ def to_posix_time(dt):
     return (dt - datetime.datetime(1970, 1, 1)).total_seconds()
 
 
-class Reporter(object):
+class Reporter:
     """A monitor process for monitoring Ray nodes.
 
     Attributes:

python/ray/runtime_context.py

@@ -5,7 +5,7 @@ from __future__ import print_function
 import ray.worker
 
 
-class RuntimeContext(object):
+class RuntimeContext:
     """A class used for getting runtime context."""
 
     def __init__(self, worker=None):

python/ray/serialization.py

@@ -40,7 +40,7 @@ class DeserializationError(Exception):
     pass
 
 
-class SerializedObject(object):
+class SerializedObject:
     def __init__(self, metadata):
         self._metadata = metadata
 
@@ -132,7 +132,7 @@ def _try_to_compute_deterministic_class_id(cls, depth=5):
     return hashlib.sha1(new_class_id).digest()
 
 
-class SerializationContext(object):
+class SerializationContext:
     """Initialize the serialization library.
 
     This defines a custom serializer for object IDs and also tells ray to

python/ray/state.py

@@ -121,7 +121,7 @@ def _parse_resource_table(redis_client, client_id):
     return resources
 
 
-class GlobalState(object):
+class GlobalState:
     """A class used to interface with the Ray control state.
 
     # TODO(zongheng): In the future move this to use Ray's redis module in the

python/ray/tests/py3_test.py

@@ -100,7 +100,7 @@ def test_args_intertwined(ray_start_regular):
 
 def test_asyncio_actor(ray_start_regular_shared):
     @ray.remote
-    class AsyncBatcher(object):
+    class AsyncBatcher:
         def __init__(self):
             self.batch = []
             self.event = asyncio.Event()

python/ray/tests/test_actor.py

@@ -22,7 +22,7 @@ from ray.experimental.internal_kv import _internal_kv_get, _internal_kv_put
 
 def test_actor_init_error_propagated(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self, error=False):
             if error:
                 raise Exception("oops")
@@ -40,7 +40,7 @@ def test_actor_init_error_propagated(ray_start_regular):
 
 def test_keyword_args(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self, arg0, arg1=1, arg2="a"):
             self.arg0 = arg0
             self.arg1 = arg1
@@ -89,7 +89,7 @@ def test_keyword_args(ray_start_regular):
 
 def test_variable_number_of_args(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self, arg0, arg1=1, *args):
             self.arg0 = arg0
             self.arg1 = arg1
@@ -113,7 +113,7 @@ def test_variable_number_of_args(ray_start_regular):
         2, 3, 1, 2, 3, 4)) == (3, 5, ("a", "b", "c", "d"), (1, 2, 3, 4))
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self, *args):
             self.args = args
 
@@ -130,7 +130,7 @@ def test_variable_number_of_args(ray_start_regular):
 
 def test_no_args(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -144,7 +144,7 @@ def test_no_args(ray_start_regular):
 def test_no_constructor(ray_start_regular):
     # If no __init__ method is provided, that should not be a problem.
     @ray.remote
-    class Actor(object):
+    class Actor:
         def get_values(self):
             pass
 
@@ -153,12 +153,12 @@ def test_no_constructor(ray_start_regular):
 
 
 def test_custom_classes(ray_start_regular):
-    class Foo(object):
+    class Foo:
         def __init__(self, x):
             self.x = x
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self, f2):
             self.f1 = Foo(1)
             self.f2 = f2
@@ -180,13 +180,13 @@ def test_custom_classes(ray_start_regular):
 
 
 def test_actor_class_attributes(ray_start_regular):
-    class Grandparent(object):
+    class Grandparent:
         GRANDPARENT = 2
 
     class Parent1(Grandparent):
         PARENT1 = 6
 
-    class Parent2(object):
+    class Parent2:
         PARENT2 = 7
 
     @ray.remote
@@ -216,7 +216,7 @@ def test_caching_actors(shutdown_only):
     # Test defining actors before ray.init() has been called.
 
     @ray.remote
-    class Foo(object):
+    class Foo:
         def __init__(self):
             pass
 
@@ -240,7 +240,7 @@ def test_decorator_args(ray_start_regular):
     with pytest.raises(Exception):
 
         @ray.remote()
-        class Actor(object):
+        class Actor:
             def __init__(self):
                 pass
 
@@ -248,7 +248,7 @@ def test_decorator_args(ray_start_regular):
     with pytest.raises(Exception):
 
         @ray.remote(invalid_kwarg=0)  # noqa: F811
-        class Actor(object):
+        class Actor:
             def __init__(self):
                 pass
 
@@ -256,32 +256,32 @@ def test_decorator_args(ray_start_regular):
     with pytest.raises(Exception):
 
         @ray.remote(num_cpus=0, invalid_kwarg=0)  # noqa: F811
-        class Actor(object):
+        class Actor:
             def __init__(self):
                 pass
 
     # This is a valid way of using the decorator.
     @ray.remote(num_cpus=1)  # noqa: F811
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
     # This is a valid way of using the decorator.
     @ray.remote(num_gpus=1)  # noqa: F811
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
     # This is a valid way of using the decorator.
     @ray.remote(num_cpus=1, num_gpus=1)  # noqa: F811
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
 
 def test_random_id_generation(ray_start_regular):
     @ray.remote
-    class Foo(object):
+    class Foo:
         def __init__(self):
             pass
 
@@ -299,7 +299,7 @@ def test_random_id_generation(ray_start_regular):
 
 def test_actor_class_name(ray_start_regular):
     @ray.remote
-    class Foo(object):
+    class Foo:
         def __init__(self):
             pass
 
@@ -314,7 +314,7 @@ def test_actor_class_name(ray_start_regular):
 
 
 def test_actor_inheritance(ray_start_regular):
-    class NonActorBase(object):
+    class NonActorBase:
         def __init__(self):
             pass
 
@@ -342,7 +342,7 @@ def test_actor_inheritance(ray_start_regular):
 
 def test_multiple_return_values(ray_start_regular):
     @ray.remote
-    class Foo(object):
+    class Foo:
         def method0(self):
             return 1
 
@@ -375,7 +375,7 @@ def test_multiple_return_values(ray_start_regular):
 
 def test_define_actor(ray_start_regular):
     @ray.remote
-    class Test(object):
+    class Test:
         def __init__(self, x):
             self.x = x
 
@@ -395,7 +395,7 @@ def test_actor_deletion(ray_start_regular):
     # destructor is called.
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def getpid(self):
             return os.getpid()
 
@@ -413,7 +413,7 @@ def test_actor_deletion(ray_start_regular):
 
 def test_actor_method_deletion(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def method(self):
             return 1
 
@@ -426,7 +426,7 @@ def test_actor_method_deletion(ray_start_regular):
 
 def test_multiple_actors(ray_start_regular):
     @ray.remote
-    class Counter(object):
+    class Counter:
         def __init__(self, value):
             self.value = value
 
@@ -479,7 +479,7 @@ def test_remote_function_within_actor(ray_start_10_cpus):
         return ray.get(f.remote(x))
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self, x):
             self.x = x
             self.y = val2
@@ -515,13 +515,13 @@ def test_define_actor_within_actor(ray_start_10_cpus):
     # Make sure we can use remote funtions within actors.
 
     @ray.remote
-    class Actor1(object):
+    class Actor1:
         def __init__(self, x):
             self.x = x
 
         def new_actor(self, z):
             @ray.remote
-            class Actor2(object):
+            class Actor2:
                 def __init__(self, x):
                     self.x = x
 
@@ -542,7 +542,7 @@ def test_use_actor_within_actor(ray_start_10_cpus):
     # Make sure we can use actors within actors.
 
     @ray.remote
-    class Actor1(object):
+    class Actor1:
         def __init__(self, x):
             self.x = x
 
@@ -550,7 +550,7 @@ def test_use_actor_within_actor(ray_start_10_cpus):
             return self.x
 
     @ray.remote
-    class Actor2(object):
+    class Actor2:
         def __init__(self, x, y):
             self.x = x
             self.actor1 = Actor1.remote(y)
@@ -568,7 +568,7 @@ def test_define_actor_within_remote_function(ray_start_10_cpus):
     @ray.remote
     def f(x, n):
         @ray.remote
-        class Actor1(object):
+        class Actor1:
             def __init__(self, x):
                 self.x = x
 
@@ -587,7 +587,7 @@ def test_use_actor_within_remote_function(ray_start_10_cpus):
     # Make sure we can create and use actors within remote funtions.
 
     @ray.remote
-    class Actor1(object):
+    class Actor1:
         def __init__(self, x):
             self.x = x
 
@@ -618,7 +618,7 @@ def test_actor_import_counter(ray_start_10_cpus):
     @ray.remote
     def g():
         @ray.remote
-        class Actor(object):
+        class Actor:
             def __init__(self):
                 # This should use the last version of f.
                 self.x = ray.get(f.remote())
@@ -636,7 +636,7 @@ def test_inherit_actor_from_class(ray_start_regular):
     # Make sure we can define an actor by inheriting from a regular class.
     # Note that actors cannot inherit from other actors.
 
-    class Foo(object):
+    class Foo:
         def __init__(self, x):
             self.x = x
 
@@ -663,7 +663,7 @@ def test_remote_functions_not_scheduled_on_actors(ray_start_regular):
     # Make sure that regular remote functions are not scheduled on actors.
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -683,7 +683,7 @@ def test_remote_functions_not_scheduled_on_actors(ray_start_regular):
 
 def test_actors_on_nodes_with_no_cpus(ray_start_no_cpu):
     @ray.remote
-    class Foo(object):
+    class Foo:
         def method(self):
             pass
 
@@ -700,7 +700,7 @@ def test_actor_load_balancing(ray_start_cluster):
     ray.init(address=cluster.address)
 
     @ray.remote
-    class Actor1(object):
+    class Actor1:
         def __init__(self):
             pass
 
@@ -743,7 +743,7 @@ def test_actor_lifetime_load_balancing(ray_start_cluster):
     ray.init(address=cluster.address)
 
     @ray.remote(num_cpus=1)
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -759,7 +759,7 @@ def test_exception_raised_when_actor_node_dies(ray_start_cluster_head):
     remote_node = cluster.add_node()
 
     @ray.remote(max_reconstructions=0)
-    class Counter(object):
+    class Counter:
         def __init__(self):
             self.x = 0
 
@@ -799,7 +799,7 @@ def test_actor_init_fails(ray_start_cluster_head):
     remote_node = cluster.add_node()
 
     @ray.remote(max_reconstructions=1)
-    class Counter(object):
+    class Counter:
         def __init__(self):
             self.x = 0
 
@@ -825,7 +825,7 @@ def test_reconstruction_suppression(ray_start_cluster_head):
     worker_nodes = [cluster.add_node() for _ in range(num_nodes)]
 
     @ray.remote(max_reconstructions=1)
-    class Counter(object):
+    class Counter:
         def __init__(self):
             self.x = 0
 
@@ -863,7 +863,7 @@ def setup_counter_actor(test_checkpoint=False,
         checkpoint_interval = 5
 
     @ray.remote(checkpoint_interval=checkpoint_interval)
-    class Counter(object):
+    class Counter:
         _resume_exception = resume_exception
 
         def __init__(self, save_exception):
@@ -1031,7 +1031,7 @@ def _test_nondeterministic_reconstruction(
         cluster, num_forks, num_items_per_fork, num_forks_to_wait):
     # Make a shared queue.
     @ray.remote
-    class Queue(object):
+    class Queue:
         def __init__(self):
             self.queue = []
 
@@ -1115,7 +1115,7 @@ def setup_queue_actor():
     ray.init(num_cpus=1, object_store_memory=int(150 * 1024 * 1024))
 
     @ray.remote
-    class Queue(object):
+    class Queue:
         def __init__(self):
             self.queue = []
 
@@ -1274,7 +1274,7 @@ def test_garbage_collection(setup_queue_actor):
 
 def test_calling_put_on_actor_handle(ray_start_regular):
     @ray.remote
-    class Counter(object):
+    class Counter:
         def __init__(self):
             self.x = 0
 
@@ -1308,7 +1308,7 @@ def test_calling_put_on_actor_handle(ray_start_regular):
 
 def test_pickling_actor_handle(ray_start_regular):
     @ray.remote
-    class Foo(object):
+    class Foo:
         def method(self):
             pass
 
@@ -1321,12 +1321,12 @@ def test_pickling_actor_handle(ray_start_regular):
 
 def test_pickled_actor_handle_call_in_method_twice(ray_start_regular):
     @ray.remote
-    class Actor1(object):
+    class Actor1:
         def f(self):
             return 1
 
     @ray.remote
-    class Actor2(object):
+    class Actor2:
         def __init__(self, constructor):
             self.actor = constructor()
 
@@ -1345,7 +1345,7 @@ def test_register_and_get_named_actors(ray_start_regular):
     # TODO(heyucongtom): We should test this from another driver.
 
     @ray.remote
-    class Foo(object):
+    class Foo:
         def __init__(self):
             self.x = 0
 
@@ -1381,7 +1381,7 @@ def test_register_and_get_named_actors(ray_start_regular):
 
 def test_detached_actor(ray_start_regular):
     @ray.remote
-    class DetachedActor(object):
+    class DetachedActor:
         def ping(self):
             return "pong"
 
@@ -1400,7 +1400,7 @@ import ray
 ray.init(address="{}")
 
 @ray.remote
-class DetachedActor(object):
+class DetachedActor:
     def ping(self):
         return "pong"
 
@@ -1415,7 +1415,7 @@ ray.get(actor.ping.remote())
 
 def test_kill(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def hang(self):
             # Never returns.
             ray.get(ray.ObjectID.from_random())
@@ -1434,7 +1434,7 @@ def test_kill(ray_start_regular):
 def test_actor_creation_task_crash(ray_start_regular):
     # Test actor death in constructor.
     @ray.remote(max_reconstructions=0)
-    class Actor(object):
+    class Actor:
         def __init__(self):
             print("crash")
             os._exit(0)
@@ -1450,7 +1450,7 @@ def test_actor_creation_task_crash(ray_start_regular):
     # Test an actor can be reconstructed successfully
     # afte it dies in its constructor.
     @ray.remote(max_reconstructions=3)
-    class ReconstructableActor(object):
+    class ReconstructableActor:
         def __init__(self):
             count = self.get_count()
             count += 1

python/ray/tests/test_actor_failures.py

@@ -96,7 +96,7 @@ def test_actor_eviction(ray_start_object_store_memory):
     object_store_memory = ray_start_object_store_memory
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -134,7 +134,7 @@ def test_actor_reconstruction(ray_start_regular):
     """Test actor reconstruction when actor process is killed."""
 
     @ray.remote(max_reconstructions=1)
-    class ReconstructableActor(object):
+    class ReconstructableActor:
         """An actor that will be reconstructed at most once."""
 
         def __init__(self):
@@ -183,7 +183,7 @@ def test_actor_reconstruction_without_task(ray_start_regular):
     """Test a dead actor can be reconstructed without sending task to it."""
 
     @ray.remote(max_reconstructions=1)
-    class ReconstructableActor(object):
+    class ReconstructableActor:
         def __init__(self, obj_ids):
             for obj_id in obj_ids:
                 # Every time the actor gets constructed,
@@ -231,7 +231,7 @@ def test_actor_reconstruction_on_node_failure(ray_start_cluster_head):
         cluster.remove_node(node_to_remove)
 
     @ray.remote(max_reconstructions=max_reconstructions, resources={"a": 1})
-    class MyActor(object):
+    class MyActor:
         def __init__(self):
             self.value = 0
 
@@ -296,7 +296,7 @@ def test_multiple_actor_reconstruction(ray_start_cluster_head):
     ]
 
     @ray.remote(max_reconstructions=ray.ray_constants.INFINITE_RECONSTRUCTION)
-    class SlowCounter(object):
+    class SlowCounter:
         def __init__(self):
             self.x = 0
 
@@ -636,7 +636,7 @@ def test_decorated_method(ray_start_regular):
         return new_f_execution
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         @method_execution_decorator
         def decorated_method(self, x):
             return x + 1
@@ -663,7 +663,7 @@ def test_ray_wait_dead_actor(ray_start_cluster):
     cluster = ray_start_cluster
 
     @ray.remote(num_cpus=1)
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -707,7 +707,7 @@ def test_ray_wait_dead_actor(ray_start_cluster):
     ray.experimental.set_resource(head_node_resource, 1)
 
     @ray.remote(num_cpus=0, resources={head_node_resource: 1})
-    class ParentActor(object):
+    class ParentActor:
         def __init__(self, ping_ids):
             self.unready = ping_ids
 

python/ray/tests/test_actor_pool.py

@@ -18,7 +18,7 @@ def init():
 
 def test_get_next(init):
     @ray.remote
-    class MyActor(object):
+    class MyActor:
         def __init__(self):
             pass
 
@@ -37,7 +37,7 @@ def test_get_next(init):
 
 def test_get_next_unordered(init):
     @ray.remote
-    class MyActor(object):
+    class MyActor:
         def __init__(self):
             pass
 
@@ -62,7 +62,7 @@ def test_get_next_unordered(init):
 
 def test_map(init):
     @ray.remote
-    class MyActor(object):
+    class MyActor:
         def __init__(self):
             pass
 
@@ -83,7 +83,7 @@ def test_map(init):
 
 def test_map_unordered(init):
     @ray.remote
-    class MyActor(object):
+    class MyActor:
         def __init__(self):
             pass
 
@@ -105,7 +105,7 @@ def test_map_unordered(init):
 
 def test_get_next_timeout(init):
     @ray.remote
-    class MyActor(object):
+    class MyActor:
         def __init__(self):
             pass
 
@@ -127,7 +127,7 @@ def test_get_next_timeout(init):
 
 def test_get_next_unordered_timeout(init):
     @ray.remote
-    class MyActor(object):
+    class MyActor:
         def __init__(self):
             pass
 

python/ray/tests/test_actor_resources.py

@@ -29,7 +29,7 @@ def test_actor_deletion_with_gpus(shutdown_only):
     # are released.
 
     @ray.remote(num_gpus=1)
-    class Actor(object):
+    class Actor:
         def getpid(self):
             return os.getpid()
 
@@ -42,7 +42,7 @@ def test_actor_deletion_with_gpus(shutdown_only):
 
 def test_actor_state(ray_start_regular):
     @ray.remote
-    class Counter(object):
+    class Counter:
         def __init__(self):
             self.value = 0
 
@@ -63,7 +63,7 @@ def test_actor_state(ray_start_regular):
 
 
 def test_actor_class_methods(ray_start_regular):
-    class Foo(object):
+    class Foo:
         x = 2
 
         @classmethod
@@ -98,7 +98,7 @@ def test_resource_assignment(shutdown_only):
         resources={"Custom": 1},
         object_store_memory=int(150 * 1024 * 1024))
 
-    class Actor(object):
+    class Actor:
         def __init__(self):
             self.resources = ray.get_resource_ids()
 
@@ -188,7 +188,7 @@ def test_actor_gpus(ray_start_cluster):
     ray.init(address=cluster.address)
 
     @ray.remote(num_gpus=1)
-    class Actor1(object):
+    class Actor1:
         def __init__(self):
             self.gpu_ids = ray.get_gpu_ids()
 
@@ -227,7 +227,7 @@ def test_actor_multiple_gpus(ray_start_cluster):
     ray.init(address=cluster.address)
 
     @ray.remote(num_gpus=2)
-    class Actor1(object):
+    class Actor1:
         def __init__(self):
             self.gpu_ids = ray.get_gpu_ids()
 
@@ -259,7 +259,7 @@ def test_actor_multiple_gpus(ray_start_cluster):
 
     # We should be able to create more actors that use only a single GPU.
     @ray.remote(num_gpus=1)
-    class Actor2(object):
+    class Actor2:
         def __init__(self):
             self.gpu_ids = ray.get_gpu_ids()
 
@@ -297,7 +297,7 @@ def test_actor_different_numbers_of_gpus(ray_start_cluster):
     ray.init(address=cluster.address)
 
     @ray.remote(num_gpus=1)
-    class Actor1(object):
+    class Actor1:
         def __init__(self):
             self.gpu_ids = ray.get_gpu_ids()
 
@@ -343,7 +343,7 @@ def test_actor_multiple_gpus_from_multiple_tasks(ray_start_cluster):
     @ray.remote
     def create_actors(i, n):
         @ray.remote(num_gpus=1)
-        class Actor(object):
+        class Actor:
             def __init__(self, i, j):
                 self.gpu_ids = ray.get_gpu_ids()
 
@@ -389,7 +389,7 @@ def test_actor_multiple_gpus_from_multiple_tasks(ray_start_cluster):
         assert len(set(gpus_in_use[node_name])) == num_gpus_per_raylet
 
     @ray.remote(num_gpus=1)
-    class Actor(object):
+    class Actor:
         def __init__(self):
             self.gpu_ids = ray.get_gpu_ids()
 
@@ -452,7 +452,7 @@ def test_actors_and_tasks_with_gpus(ray_start_cluster):
                 [t1, t2])
 
     @ray.remote(num_gpus=1)
-    class Actor1(object):
+    class Actor1:
         def __init__(self):
             self.gpu_ids = ray.get_gpu_ids()
             assert len(self.gpu_ids) == 1
@@ -528,7 +528,7 @@ def test_actors_and_tasks_with_gpus_version_two(shutdown_only):
     # for a long time in order to make sure the GPU is not released
     # prematurely.
     @ray.remote
-    class RecordGPUs(object):
+    class RecordGPUs:
         def __init__(self):
             self.gpu_ids_seen = []
             self.num_calls = 0
@@ -550,7 +550,7 @@ def test_actors_and_tasks_with_gpus_version_two(shutdown_only):
         time.sleep(1000)
 
     @ray.remote(num_gpus=1)
-    class Actor(object):
+    class Actor:
         def __init__(self, record_gpu_actor):
             self.gpu_ids = ray.get_gpu_ids()
             assert len(self.gpu_ids) == 1
@@ -592,7 +592,7 @@ def test_blocking_actor_task(shutdown_only):
         return 1
 
     @ray.remote
-    class Foo(object):
+    class Foo:
         def __init__(self):
             pass
 
@@ -605,7 +605,7 @@ def test_blocking_actor_task(shutdown_only):
     ray.get(actor.blocking_method.remote())
 
     @ray.remote(num_cpus=1)
-    class CPUFoo(object):
+    class CPUFoo:
         def __init__(self):
             pass
 
@@ -621,7 +621,7 @@ def test_blocking_actor_task(shutdown_only):
     assert remaining_ids == [x_id]
 
     @ray.remote(num_gpus=1)
-    class GPUFoo(object):
+    class GPUFoo:
         def __init__(self):
             pass
 
@@ -639,13 +639,13 @@ def test_blocking_actor_task(shutdown_only):
 def test_lifetime_and_transient_resources(ray_start_regular):
     # This actor acquires resources only when running methods.
     @ray.remote
-    class Actor1(object):
+    class Actor1:
         def method(self):
             pass
 
     # This actor acquires resources for its lifetime.
     @ray.remote(num_cpus=1)
-    class Actor2(object):
+    class Actor2:
         def method(self):
             pass
 
@@ -666,12 +666,12 @@ def test_custom_label_placement(ray_start_cluster):
     ray.init(address=cluster.address)
 
     @ray.remote(resources={"CustomResource1": 1})
-    class ResourceActor1(object):
+    class ResourceActor1:
         def get_location(self):
             return ray.worker.global_worker.node.unique_id
 
     @ray.remote(resources={"CustomResource2": 1})
-    class ResourceActor2(object):
+    class ResourceActor2:
         def get_location(self):
             return ray.worker.global_worker.node.unique_id
 
@@ -692,12 +692,12 @@ def test_creating_more_actors_than_resources(shutdown_only):
     ray.init(num_cpus=10, num_gpus=2, resources={"CustomResource1": 1})
 
     @ray.remote(num_gpus=1)
-    class ResourceActor1(object):
+    class ResourceActor1:
         def method(self):
             return ray.get_gpu_ids()[0]
 
     @ray.remote(resources={"CustomResource1": 1})
-    class ResourceActor2(object):
+    class ResourceActor2:
         def method(self):
             pass
 

python/ray/tests/test_advanced.py

@@ -373,7 +373,7 @@ def test_multithreading(ray_start_2_cpus):
         """Test using Ray api in multiple threads."""
 
         @ray.remote
-        class Echo(object):
+        class Echo:
             def echo(self, value):
                 return value
 
@@ -433,7 +433,7 @@ def test_multithreading(ray_start_2_cpus):
 
     # Test actor that runs background threads.
     @ray.remote
-    class MultithreadedActor(object):
+    class MultithreadedActor:
         def __init__(self):
             self.lock = threading.Lock()
             self.thread_results = []
@@ -504,7 +504,7 @@ def test_free_objects_multi_node(ray_start_cluster):
             _internal_config=config)
     ray.init(address=cluster.address)
 
-    class RawActor(object):
+    class RawActor:
         def get(self):
             return ray.worker.global_worker.node.unique_id
 
@@ -633,7 +633,7 @@ def test_local_mode(shutdown_only):
     # Test actors in LOCAL_MODE.
 
     @ray.remote
-    class LocalModeTestClass(object):
+    class LocalModeTestClass:
         def __init__(self, array):
             self.array = array
 
@@ -718,7 +718,7 @@ def test_local_mode(shutdown_only):
     # Check that Actors are not overwritten by remote calls from different
     # classes.
     @ray.remote
-    class RemoteActor1(object):
+    class RemoteActor1:
         def __init__(self):
             pass
 
@@ -726,7 +726,7 @@ def test_local_mode(shutdown_only):
             return 0
 
     @ray.remote
-    class RemoteActor2(object):
+    class RemoteActor2:
         def __init__(self):
             pass
 
@@ -756,7 +756,7 @@ def test_wait_makes_object_local(ray_start_cluster):
     ray.init(address=cluster.address)
 
     @ray.remote
-    class Foo(object):
+    class Foo:
         def method(self):
             return np.zeros(1024 * 1024)
 

python/ray/tests/test_advanced_2.py

@@ -191,7 +191,7 @@ def test_gpu_ids(shutdown_only):
     # Test that actors have CUDA_VISIBLE_DEVICES set properly.
 
     @ray.remote
-    class Actor0(object):
+    class Actor0:
         def __init__(self):
             gpu_ids = ray.get_gpu_ids()
             assert len(gpu_ids) == 0
@@ -208,7 +208,7 @@ def test_gpu_ids(shutdown_only):
             return self.x
 
     @ray.remote(num_gpus=1)
-    class Actor1(object):
+    class Actor1:
         def __init__(self):
             gpu_ids = ray.get_gpu_ids()
             assert len(gpu_ids) == 1
@@ -243,7 +243,7 @@ def test_zero_cpus(shutdown_only):
 
     # We should be able to create an actor that requires 0 CPU resources.
     @ray.remote(num_cpus=0)
-    class Actor(object):
+    class Actor:
         def method(self):
             pass
 
@@ -261,7 +261,7 @@ def test_zero_cpus_actor(ray_start_cluster):
     node_id = ray.worker.global_worker.node.unique_id
 
     @ray.remote
-    class Foo(object):
+    class Foo:
         def method(self):
             return ray.worker.global_worker.node.unique_id
 
@@ -274,7 +274,7 @@ def test_fractional_resources(shutdown_only):
     ray.init(num_cpus=6, num_gpus=3, resources={"Custom": 1})
 
     @ray.remote(num_gpus=0.5)
-    class Foo1(object):
+    class Foo1:
         def method(self):
             gpu_ids = ray.get_gpu_ids()
             assert len(gpu_ids) == 1
@@ -287,7 +287,7 @@ def test_fractional_resources(shutdown_only):
     del foos
 
     @ray.remote
-    class Foo2(object):
+    class Foo2:
         def method(self):
             pass
 

python/ray/tests/test_advanced_3.py

@@ -260,7 +260,7 @@ def test_global_state_task_object_api(shutdown_only):
 
 # TODO(rkn): Pytest actually has tools for capturing stdout and stderr, so we
 # should use those, but they seem to conflict with Ray's use of faulthandler.
-class CaptureOutputAndError(object):
+class CaptureOutputAndError:
     """Capture stdout and stderr of some span.
 
     This can be used as follows.
@@ -434,7 +434,7 @@ def test_wait_reconstruction(shutdown_only):
 
 def test_ray_setproctitle(ray_start_2_cpus):
     @ray.remote
-    class UniqueName(object):
+    class UniqueName:
         def __init__(self):
             assert setproctitle.getproctitle() == "ray::UniqueName.__init__()"
 
@@ -667,7 +667,7 @@ def test_export_after_shutdown(ray_start_regular):
         pass
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def method(self):
             pass
 
@@ -731,7 +731,7 @@ def test_move_log_files_to_old(shutdown_only):
     logs_dir = os.path.join(info["session_dir"], "logs")
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def f(self):
             print("function f finished")
 

python/ray/tests/test_autoscaler.py

@@ -21,7 +21,7 @@ from ray.test_utils import RayTestTimeoutException
 import pytest
 
 
-class MockNode(object):
+class MockNode:
     def __init__(self, node_id, tags):
         self.node_id = node_id
         self.state = "pending"
@@ -36,7 +36,7 @@ class MockNode(object):
         return True
 
 
-class MockProcessRunner(object):
+class MockProcessRunner:
     def __init__(self, fail_cmds=[]):
         self.calls = []
         self.fail_cmds = fail_cmds

python/ray/tests/test_basic.py

@@ -217,7 +217,7 @@ def complex_serialization(use_pickle):
         },
     ]
 
-    class Foo(object):
+    class Foo:
         def __init__(self, value=0):
             self.value = value
 
@@ -227,12 +227,12 @@ def complex_serialization(use_pickle):
         def __eq__(self, other):
             return other.value == self.value
 
-    class Bar(object):
+    class Bar:
         def __init__(self):
             for i, val in enumerate(PRIMITIVE_OBJECTS + COMPLEX_OBJECTS):
                 setattr(self, "field{}".format(i), val)
 
-    class Baz(object):
+    class Baz:
         def __init__(self):
             self.foo = Foo()
             self.bar = Bar()
@@ -240,7 +240,7 @@ def complex_serialization(use_pickle):
         def method(self, arg):
             pass
 
-    class Qux(object):
+    class Qux:
         def __init__(self):
             self.objs = [Foo(), Bar(), Baz()]
 
@@ -273,7 +273,7 @@ def complex_serialization(use_pickle):
 
         CUSTOM_OBJECTS.append(DataClass0(number=3))
 
-        class CustomClass(object):
+        class CustomClass:
             def __init__(self, value):
                 self.value = value
 
@@ -385,7 +385,7 @@ def test_nested_functions(ray_start_regular):
 
 
 def test_ray_recursive_objects(ray_start_regular):
-    class ClassA(object):
+    class ClassA:
         pass
 
     # Make a list that contains itself.
@@ -440,7 +440,7 @@ def test_passing_arguments_by_value_out_of_the_box(ray_start_regular):
     assert ray.get(f.remote(float)) == float
     assert ray.get(f.remote(str)) == str
 
-    class Foo(object):
+    class Foo:
         def __init__(self):
             pass
 
@@ -453,7 +453,7 @@ def test_putting_object_that_closes_over_object_id(ray_start_regular):
     # This test is here to prevent a regression of
     # https://github.com/ray-project/ray/issues/1317.
 
-    class Foo(object):
+    class Foo:
         def __init__(self):
             self.val = ray.put(0)
 
@@ -493,7 +493,7 @@ def test_put_get(shutdown_only):
 
 
 def custom_serializers():
-    class Foo(object):
+    class Foo:
         def __init__(self):
             self.x = 3
 
@@ -508,7 +508,7 @@ def custom_serializers():
 
     assert ray.get(ray.put(Foo())) == ((3, "string1", Foo.__name__), "string2")
 
-    class Bar(object):
+    class Bar:
         def __init__(self):
             self.x = 3
 
@@ -530,7 +530,7 @@ def test_custom_serializers_with_pickle(shutdown_only):
     ray.init(use_pickle=True)
     custom_serializers()
 
-    class Foo(object):
+    class Foo:
         def __init__(self):
             self.x = 4
 
@@ -566,7 +566,7 @@ def test_serialization_final_fallback(ray_start_regular):
 def test_register_class(ray_start_2_cpus):
     # Check that putting an object of a class that has not been registered
     # throws an exception.
-    class TempClass(object):
+    class TempClass:
         pass
 
     ray.get(ray.put(TempClass()))
@@ -576,7 +576,7 @@ def test_register_class(ray_start_2_cpus):
     def f(x):
         return x
 
-    class Foo(object):
+    class Foo:
         def __init__(self, value=0):
             self.value = value
 
@@ -597,14 +597,14 @@ def test_register_class(ray_start_2_cpus):
     # Instead, we do this:
     assert regex.pattern == new_regex.pattern
 
-    class TempClass1(object):
+    class TempClass1:
         def __init__(self):
             self.value = 1
 
     # Test returning custom classes created on workers.
     @ray.remote
     def g():
-        class TempClass2(object):
+        class TempClass2:
             def __init__(self):
                 self.value = 2
 
@@ -616,7 +616,7 @@ def test_register_class(ray_start_2_cpus):
 
     # Test exporting custom class definitions from one worker to another
     # when the worker is blocked in a get.
-    class NewTempClass(object):
+    class NewTempClass:
         def __init__(self, value):
             self.value = value
 
@@ -633,19 +633,19 @@ def test_register_class(ray_start_2_cpus):
     # Test registering multiple classes with the same name.
     @ray.remote(num_return_vals=3)
     def j():
-        class Class0(object):
+        class Class0:
             def method0(self):
                 pass
 
         c0 = Class0()
 
-        class Class0(object):
+        class Class0:
             def method1(self):
                 pass
 
         c1 = Class0()
 
-        class Class0(object):
+        class Class0:
             def method2(self):
                 pass
 
@@ -672,19 +672,19 @@ def test_register_class(ray_start_2_cpus):
 
     @ray.remote
     def k():
-        class Class0(object):
+        class Class0:
             def method0(self):
                 pass
 
         c0 = Class0()
 
-        class Class0(object):
+        class Class0:
             def method1(self):
                 pass
 
         c1 = Class0()
 
-        class Class0(object):
+        class Class0:
             def method2(self):
                 pass
 
@@ -804,7 +804,7 @@ def test_args_starkwargs(ray_start_regular):
     def starkwargs(a, b, **kwargs):
         return a, b, kwargs
 
-    class TestActor(object):
+    class TestActor:
         def starkwargs(self, a, b, **kwargs):
             return a, b, kwargs
 
@@ -841,7 +841,7 @@ def test_args_named_and_star(ray_start_regular):
     def hello(a, x="hello", **kwargs):
         return a, x, kwargs
 
-    class TestActor(object):
+    class TestActor:
         def hello(self, a, x="hello", **kwargs):
             return a, x, kwargs
 
@@ -884,7 +884,7 @@ def test_args_stars_after(ray_start_regular):
     def star_args_after(a="hello", b="heo", *args, **kwargs):
         return a, b, args, kwargs
 
-    class TestActor(object):
+    class TestActor:
         def star_args_after(self, a="hello", b="heo", *args, **kwargs):
             return a, b, args, kwargs
 
@@ -1089,7 +1089,7 @@ def test_submit_api(shutdown_only):
     assert len(remaining_ids) == 1
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self, x, y=0):
             self.x = x
             self.y = y
@@ -1101,7 +1101,7 @@ def test_submit_api(shutdown_only):
             return ray.get_gpu_ids()
 
     @ray.remote
-    class Actor2(object):
+    class Actor2:
         def __init__(self):
             pass
 
@@ -1250,7 +1250,7 @@ def test_direct_call_simple(ray_start_cluster):
 # https://github.com/ray-project/ray/issues/6329
 def test_call_actors_indirect_through_tasks(ray_start_regular):
     @ray.remote
-    class Counter(object):
+    class Counter:
         def __init__(self, value):
             self.value = int(value)
 
@@ -1302,7 +1302,7 @@ def test_direct_call_matrix(shutdown_only):
     ray.init(object_store_memory=1000 * 1024 * 1024)
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def small_value(self):
             return 0
 
@@ -1390,7 +1390,7 @@ def test_direct_inline_arg_memory_corruption(ray_start_regular):
         return np.zeros(1000, dtype=np.uint8)
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             self.z = []
 
@@ -1407,7 +1407,7 @@ def test_direct_inline_arg_memory_corruption(ray_start_regular):
 
 def test_direct_actor_enabled(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -1430,7 +1430,7 @@ def test_direct_actor_order(shutdown_only):
         return 0
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             self.count = 0
 
@@ -1448,7 +1448,7 @@ def test_direct_actor_order(shutdown_only):
 
 def test_direct_actor_large_objects(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -1467,7 +1467,7 @@ def test_direct_actor_large_objects(ray_start_regular):
 
 def test_direct_actor_pass_by_ref(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -1497,7 +1497,7 @@ def test_direct_actor_pass_by_ref_order_optimization(shutdown_only):
     ray.init(num_cpus=4)
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -1532,7 +1532,7 @@ def test_direct_actor_pass_by_ref_order_optimization(shutdown_only):
 
 def test_direct_actor_recursive(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self, delegate=None):
             self.delegate = delegate
 
@@ -1555,7 +1555,7 @@ def test_direct_actor_recursive(ray_start_regular):
 
 def test_direct_actor_concurrent(ray_start_regular):
     @ray.remote
-    class Batcher(object):
+    class Batcher:
         def __init__(self):
             self.batch = []
             self.event = threading.Event()

python/ray/tests/test_component_failures_3.py

@@ -25,7 +25,7 @@ def test_actor_creation_node_failure(ray_start_cluster):
     cluster = ray_start_cluster
 
     @ray.remote
-    class Child(object):
+    class Child:
         def __init__(self, death_probability):
             self.death_probability = death_probability
 

python/ray/tests/test_dynres.py

@@ -580,7 +580,7 @@ def test_release_cpus_when_actor_creation_task_blocking(shutdown_only):
         return 100
 
     @ray.remote(num_cpus=1)
-    class A(object):
+    class A:
         def __init__(self):
             self.num = ray.get(get_100.remote())
 

python/ray/tests/test_failure.py

@@ -167,7 +167,7 @@ def temporary_helper_function():
     # Define an actor that closes over this temporary module. This should
     # fail when it is unpickled.
     @ray.remote
-    class Foo(object):
+    class Foo:
         def __init__(self, arg1, arg2=3):
             self.x = module.temporary_python_file()
 
@@ -213,7 +213,7 @@ def test_failed_actor_init(ray_start_regular):
     error_message2 = "actor method failed"
 
     @ray.remote
-    class FailedActor(object):
+    class FailedActor:
         def __init__(self):
             raise Exception(error_message1)
 
@@ -240,7 +240,7 @@ def test_failed_actor_method(ray_start_regular):
     error_message2 = "actor method failed"
 
     @ray.remote
-    class FailedActor(object):
+    class FailedActor:
         def __init__(self):
             pass
 
@@ -259,7 +259,7 @@ def test_failed_actor_method(ray_start_regular):
 
 def test_incorrect_method_calls(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self, missing_variable_name):
             pass
 
@@ -325,7 +325,7 @@ def test_worker_dying(ray_start_regular):
 
 def test_actor_worker_dying(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def kill(self):
             eval("exit()")
 
@@ -344,7 +344,7 @@ def test_actor_worker_dying(ray_start_regular):
 
 def test_actor_worker_dying_future_tasks(ray_start_regular):
     @ray.remote(max_reconstructions=0)
-    class Actor(object):
+    class Actor:
         def getpid(self):
             return os.getpid()
 
@@ -366,7 +366,7 @@ def test_actor_worker_dying_future_tasks(ray_start_regular):
 
 def test_actor_worker_dying_nothing_in_progress(ray_start_regular):
     @ray.remote(max_reconstructions=0)
-    class Actor(object):
+    class Actor:
         def getpid(self):
             return os.getpid()
 
@@ -381,7 +381,7 @@ def test_actor_worker_dying_nothing_in_progress(ray_start_regular):
 
 def test_actor_scope_or_intentionally_killed_message(ray_start_regular):
     @ray.remote
-    class Actor(object):
+    class Actor:
         pass
 
     a = Actor.remote()
@@ -532,7 +532,7 @@ def test_export_large_objects(ray_start_regular):
     wait_for_errors(ray_constants.PICKLING_LARGE_OBJECT_PUSH_ERROR, 1)
 
     @ray.remote
-    class Foo(object):
+    class Foo:
         def __init__(self):
             large_object
 
@@ -548,7 +548,7 @@ def test_warning_for_resource_deadlock(shutdown_only):
     ray.init(num_cpus=1)
 
     @ray.remote(num_cpus=1)
-    class Foo(object):
+    class Foo:
         def f(self):
             return 0
 
@@ -572,7 +572,7 @@ def test_warning_for_infeasible_tasks(ray_start_regular):
         pass
 
     @ray.remote(resources={"Custom": 1})
-    class Foo(object):
+    class Foo:
         pass
 
     # This task is infeasible.
@@ -592,7 +592,7 @@ def test_warning_for_infeasible_zero_cpu_actor(shutdown_only):
     ray.init(num_cpus=0)
 
     @ray.remote
-    class Foo(object):
+    class Foo:
         pass
 
     # The actor creation should be infeasible.
@@ -607,7 +607,7 @@ def test_warning_for_too_many_actors(shutdown_only):
     ray.init(num_cpus=num_cpus)
 
     @ray.remote
-    class Foo(object):
+    class Foo:
         def __init__(self):
             time.sleep(1000)
 
@@ -689,7 +689,7 @@ def test_warning_for_many_duplicate_remote_functions_and_actors(shutdown_only):
         # Require a GPU so that the actor is never actually created and we
         # don't spawn an unreasonable number of processes.
         @ray.remote(num_gpus=1)
-        class Foo(object):
+        class Foo:
             pass
 
         Foo.remote()
@@ -850,7 +850,7 @@ def test_connect_with_disconnected_node(shutdown_only):
 @pytest.mark.parametrize("num_actors", [1, 2, 5])
 def test_parallel_actor_fill_plasma_retry(ray_start_cluster_head, num_actors):
     @ray.remote
-    class LargeMemoryActor(object):
+    class LargeMemoryActor:
         def some_expensive_task(self):
             return np.zeros(10**8 // 2, dtype=np.uint8)
 
@@ -869,7 +869,7 @@ def test_parallel_actor_fill_plasma_retry(ray_start_cluster_head, num_actors):
     indirect=True)
 def test_fill_object_store_exception(ray_start_cluster_head):
     @ray.remote
-    class LargeMemoryActor(object):
+    class LargeMemoryActor:
         def some_expensive_task(self):
             return np.zeros(10**8 + 2, dtype=np.uint8)
 

python/ray/tests/test_garbage_collection.py

@@ -30,7 +30,7 @@ def test_basic_gc(shutdown_only):
         return np.random.shuffle(input)
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             # Hold a long-lived reference to a ray.put object. This should not
             # be garbage collected while the actor is alive.

python/ray/tests/test_memory_limits.py

@@ -10,7 +10,7 @@ OBJECT_TOO_LARGE = ray.exceptions.ObjectStoreFullError
 
 
 @ray.remote
-class LightActor(object):
+class LightActor:
     def __init__(self):
         pass
 
@@ -19,7 +19,7 @@ class LightActor(object):
 
 
 @ray.remote
-class GreedyActor(object):
+class GreedyActor:
     def __init__(self):
         pass
 

python/ray/tests/test_memory_scheduling.py

@@ -9,7 +9,7 @@ MB = 1024 * 1024
 
 
 @ray.remote(memory=100 * MB)
-class Actor(object):
+class Actor:
     def __init__(self):
         pass
 
@@ -18,7 +18,7 @@ class Actor(object):
 
 
 @ray.remote(object_store_memory=100 * MB)
-class Actor2(object):
+class Actor2:
     def __init__(self):
         pass
 

python/ray/tests/test_metrics.py

@@ -48,7 +48,7 @@ def test_worker_stats(shutdown_only):
         return os.getpid()
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -118,7 +118,7 @@ def test_raylet_info_endpoint(shutdown_only):
     addresses = ray.init(include_webui=True, num_cpus=6)
 
     @ray.remote(num_cpus=1)
-    class ActorA(object):
+    class ActorA:
         def __init__(self):
             pass
 
@@ -126,12 +126,12 @@ def test_raylet_info_endpoint(shutdown_only):
             return os.getpid()
 
     @ray.remote(resources={"CustomResource": 1})
-    class ActorB(object):
+    class ActorB:
         def __init__(self):
             pass
 
     @ray.remote(num_cpus=2)
-    class ActorC(object):
+    class ActorC:
         def __init__(self):
             self.children = [ActorA.remote(), ActorB.remote()]
 

python/ray/tests/test_mini.py

@@ -53,7 +53,7 @@ def test_put_api(ray_start_regular):
 
 def test_actor_api(ray_start_regular):
     @ray.remote
-    class Foo(object):
+    class Foo:
         def __init__(self, val):
             self.x = val
 

python/ray/tests/test_multi_node.py

@@ -143,7 +143,7 @@ def test_driver_exiting_quickly(call_ray_start):
 import ray
 ray.init(address="{}")
 @ray.remote
-class Foo(object):
+class Foo:
     def __init__(self):
         pass
 Foo.remote()
@@ -185,7 +185,7 @@ import ray
 import time
 ray.init(address="{}")
 @ray.remote
-class Counter(object):
+class Counter:
     def __init__(self):
         self.count = 0
     def increment(self):
@@ -236,7 +236,7 @@ import time
 log_message = "{}"
 
 @ray.remote
-class Actor(object):
+class Actor:
     def log(self):
         print(log_message)
 
@@ -278,7 +278,7 @@ def g(duration):
     time.sleep(duration)
 
 @ray.remote(num_gpus=1)
-class Foo(object):
+class Foo:
     def __init__(self):
         pass
 

python/ray/tests/test_multi_node_2.py

@@ -138,7 +138,7 @@ def test_heartbeats_single(ray_start_cluster_head):
     ray.get(work_handle)
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def work(self, timeout):
             time.sleep(timeout)
             return True

python/ray/tests/test_multinode_failures_2.py

@@ -94,7 +94,7 @@ def test_actor_creation_node_failure(ray_start_cluster):
     cluster = ray_start_cluster
 
     @ray.remote
-    class Child(object):
+    class Child:
         def __init__(self, death_probability):
             self.death_probability = death_probability
 

python/ray/tests/test_object_manager.py

@@ -133,7 +133,7 @@ def test_actor_broadcast(ray_start_cluster_with_resource):
     cluster, num_nodes = ray_start_cluster_with_resource
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def ready(self):
             pass
 

python/ray/tests/test_ray_init.py

@@ -18,7 +18,7 @@ def password():
     return random_bytes.encode("hex")  # Python 2
 
 
-class TestRedisPassword(object):
+class TestRedisPassword:
     @pytest.mark.skipif(
         os.environ.get("RAY_USE_NEW_GCS") == "on",
         reason="New GCS API doesn't support Redis authentication yet.")

python/ray/tests/test_signal.py

@@ -42,7 +42,7 @@ def test_send_signal_from_actor_to_driver(ray_start_regular):
     # Send several signals from an actor, and receive them in the driver.
 
     @ray.remote
-    class ActorSendSignal(object):
+    class ActorSendSignal:
         def __init__(self):
             pass
 
@@ -66,7 +66,7 @@ def test_send_signals_from_actor_to_driver(ray_start_regular):
     # these signals in the driver.
 
     @ray.remote
-    class ActorSendSignals(object):
+    class ActorSendSignals:
         def __init__(self):
             pass
 
@@ -123,7 +123,7 @@ def test_actor_crash(ray_start_regular):
     # of a method that failed.
 
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -145,7 +145,7 @@ def test_actor_crash_init(ray_start_regular):
     # Get an error when an actor's __init__ failed.
 
     @ray.remote
-    class ActorCrashInit(object):
+    class ActorCrashInit:
         def __init__(self):
             raise Exception("exception message")
 
@@ -165,7 +165,7 @@ def test_actor_crash_init2(ray_start_regular):
     # of the actor.
 
     @ray.remote
-    class ActorCrashInit(object):
+    class ActorCrashInit:
         def __init__(self):
             raise Exception("exception message")
 
@@ -188,7 +188,7 @@ def test_actor_crash_init3(ray_start_regular):
     # another method of the actor is invoked.
 
     @ray.remote
-    class ActorCrashInit(object):
+    class ActorCrashInit:
         def __init__(self):
             raise Exception("exception message")
 
@@ -209,7 +209,7 @@ def test_send_signals_from_actor_to_actor(ray_start_regular):
     # these signals in another actor.
 
     @ray.remote
-    class ActorSendSignals(object):
+    class ActorSendSignals:
         def __init__(self):
             pass
 
@@ -218,7 +218,7 @@ def test_send_signals_from_actor_to_actor(ray_start_regular):
                 signal.send(UserSignal(value + str(i)))
 
     @ray.remote
-    class ActorGetSignalsAll(object):
+    class ActorGetSignalsAll:
         def __init__(self):
             self.received_signals = []
 
@@ -257,7 +257,7 @@ def test_forget(ray_start_regular):
     # actor. Then show that the driver only gets the last "count" signals.
 
     @ray.remote
-    class ActorSendSignals(object):
+    class ActorSendSignals:
         def __init__(self):
             pass
 
@@ -278,7 +278,7 @@ def test_forget(ray_start_regular):
 def test_signal_on_node_failure(two_node_cluster):
     """Test actor checkpointing on a remote node."""
 
-    class ActorSignal(object):
+    class ActorSignal:
         def __init__(self):
             pass
 

python/ray/tests/test_stress_sharded.py

@@ -48,7 +48,7 @@ def test_submitting_many_tasks(ray_start_sharded):
 
 def test_submitting_many_actors_to_one(ray_start_sharded):
     @ray.remote
-    class Actor(object):
+    class Actor:
         def __init__(self):
             pass
 
@@ -56,7 +56,7 @@ def test_submitting_many_actors_to_one(ray_start_sharded):
             return
 
     @ray.remote
-    class Worker(object):
+    class Worker:
         def __init__(self, actor):
             self.actor = actor
 

python/ray/tests/test_tensorflow.py

@@ -22,7 +22,7 @@ def make_linear_network(w_name=None, b_name=None):
             tf.global_variables_initializer(), x_data, y_data)
 
 
-class LossActor(object):
+class LossActor:
     def __init__(self, use_loss=True):
         # Uses a separate graph for each network.
         with tf.Graph().as_default():
@@ -45,7 +45,7 @@ class LossActor(object):
         return self.values[0].get_weights()
 
 
-class NetActor(object):
+class NetActor:
     def __init__(self):
         # Uses a separate graph for each network.
         with tf.Graph().as_default():
@@ -67,7 +67,7 @@ class NetActor(object):
         return self.values[0].get_weights()
 
 
-class TrainActor(object):
+class TrainActor:
     def __init__(self):
         # Almost the same as above, but now returns the placeholders and
         # gradient.

python/ray/tune/analysis/experiment_analysis.py

@@ -17,7 +17,7 @@ from ray.tune.result import EXPR_PROGRESS_FILE, EXPR_PARAM_FILE, CONFIG_PREFIX
 logger = logging.getLogger(__name__)
 
 
-class Analysis(object):
+class Analysis:
     """Analyze all results from a directory of experiments."""
 
     def __init__(self, experiment_dir):

python/ray/tune/automl/search_space.py

@@ -11,7 +11,7 @@ from ray.tune import grid_search
 logger = logging.getLogger(__name__)
 
 
-class ParameterSpace(object):
+class ParameterSpace:
     """Base class of a single parameter's search space.
     """
 
@@ -116,7 +116,7 @@ class ContinuousSpace(ParameterSpace):
                                                  self.end)
 
 
-class SearchSpace(object):
+class SearchSpace:
     """Collection of ``ParameterSpace``, a.k.a <name, space> pair.
 
     It's supposed to be used with a fixed experiment config, which

python/ray/tune/automlboard/backend/collector.py

@@ -17,7 +17,7 @@ from ray.tune.result import DEFAULT_RESULTS_DIR, JOB_META_FILE, \
     EXPR_PARAM_FILE, EXPR_RESULT_FILE, EXPR_META_FILE
 
 
-class CollectorService(object):
+class CollectorService:
     """Server implementation to monitor the log directory.
 
     The service will save the information of job and

python/ray/tune/checkpoint_manager.py

@@ -16,7 +16,7 @@ except NameError:
 logger = logging.getLogger(__name__)
 
 
-class Checkpoint(object):
+class Checkpoint:
     """Describes a checkpoint of trial state.
 
     Checkpoint may be saved in different storage.
@@ -54,7 +54,7 @@ class Checkpoint(object):
         return Checkpoint(Checkpoint.MEMORY, value)
 
 
-class QueueItem(object):
+class QueueItem:
     def __init__(self, priority, value):
         self.priority = priority
         self.value = value
@@ -69,7 +69,7 @@ class QueueItem(object):
         return self.priority < other.priority
 
 
-class CheckpointManager(object):
+class CheckpointManager:
     """Manages checkpoints on the driver for a trial."""
 
     def __init__(self, keep_checkpoints_num, checkpoint_score_attr):

python/ray/tune/experiment.py

@@ -34,7 +34,7 @@ def _raise_deprecation_note(deprecated, replacement, soft=False):
         raise DeprecationWarning(error_msg)
 
 
-class Experiment(object):
+class Experiment:
     """Tracks experiment specifications.
 
     Implicitly registers the Trainable if needed.

python/ray/tune/function_runner.py

@@ -24,7 +24,7 @@ ERROR_REPORT_TIMEOUT = 10
 ERROR_FETCH_TIMEOUT = 1
 
 
-class StatusReporter(object):
+class StatusReporter:
     """Object passed into your function that you can report status through.
 
     Example:

python/ray/tune/logger.py

@@ -26,7 +26,7 @@ tf = None
 VALID_SUMMARY_TYPES = [int, float, np.float32, np.float64, np.int32]
 
 
-class Logger(object):
+class Logger:
     """Logging interface for ray.tune.
 
     By default, the UnifiedLogger implementation is used which logs results in

python/ray/tune/progress_reporter.py

@@ -26,7 +26,7 @@ REPORTED_REPRESENTATIONS = {
 }
 
 
-class ProgressReporter(object):
+class ProgressReporter:
     # TODO(ujvl): Expose ProgressReporter in tune.run for custom reporting.
 
     def report(self, trial_runner):

python/ray/tune/ray_trial_executor.py

@@ -30,7 +30,7 @@ DEFAULT_GET_TIMEOUT = 30.0  # seconds
 TRIAL_START_ATTEMPTS = 3
 
 
-class _LocalWrapper(object):
+class _LocalWrapper:
     def __init__(self, result):
         self._result = result
 

python/ray/tune/registry.py

@@ -98,7 +98,7 @@ def _make_key(category, key):
             key.encode("ascii"))
 
 
-class _Registry(object):
+class _Registry:
     def __init__(self):
         self._to_flush = {}
 

python/ray/tune/sample.py

@@ -8,7 +8,7 @@ import numpy as np
 logger = logging.getLogger(__name__)
 
 
-class sample_from(object):
+class sample_from:
     """Specify that tune should sample configuration values from this function.
 
     Arguments:

python/ray/tune/schedulers/hyperband.py

@@ -294,7 +294,7 @@ class HyperBandScheduler(FIFOScheduler):
         trial_runner.trial_executor.unpause_trial(trial)
 
 
-class Bracket(object):
+class Bracket:
     """Logical object for tracking Hyperband bracket progress. Keeps track
     of proper parameters as designated by HyperBand.
 

python/ray/tune/schedulers/pbt.py

@@ -21,7 +21,7 @@ from ray.tune.trial import Trial, Checkpoint
 logger = logging.getLogger(__name__)
 
 
-class PBTTrialState(object):
+class PBTTrialState:
     """Internal PBT state tracked per-trial."""
 
     def __init__(self, trial):

python/ray/tune/schedulers/trial_scheduler.py

@@ -5,7 +5,7 @@ from __future__ import print_function
 from ray.tune.trial import Trial
 
 
-class TrialScheduler(object):
+class TrialScheduler:
     """Interface for implementing a Trial Scheduler class."""
 
     CONTINUE = "CONTINUE"  #: Status for continuing trial execution

python/ray/tune/suggest/search.py

@@ -3,7 +3,7 @@ from __future__ import division
 from __future__ import print_function
 
 
-class SearchAlgorithm(object):
+class SearchAlgorithm:
     """Interface of an event handler API for hyperparameter search.
 
     Unlike TrialSchedulers, SearchAlgorithms will not have the ability

python/ray/tune/sync_client.py

@@ -76,7 +76,7 @@ def get_cloud_sync_client(remote_path):
     return CommandBasedClient(template, template)
 
 
-class SyncClient(object):
+class SyncClient:
     """Client interface for interacting with remote storage options."""
 
     def sync_up(self, source, target):

python/ray/tune/syncer.py

@@ -60,7 +60,7 @@ def log_sync_template(options=""):
     return template.format(options=options, rsh=quote(rsh))
 
 
-class Syncer(object):
+class Syncer:
     def __init__(self, local_dir, remote_dir, sync_client=NOOP):
         """Syncs between two directories with the sync_function.
 

python/ray/tune/tests/test_api.py

@@ -192,7 +192,7 @@ class TrainableFunctionApiTest(unittest.TestCase):
         def train(config, reporter):
             pass
 
-        class A(object):
+        class A:
             pass
 
         class B(Trainable):

python/ray/tune/tests/test_commands.py

@@ -20,7 +20,7 @@ from ray.tune import commands
 from ray.tune.result import CONFIG_PREFIX
 
 
-class Capturing(object):
+class Capturing:
     def __enter__(self):
         self._stdout = sys.stdout
         sys.stdout = self._stringio = StringIO()

python/ray/tune/tests/test_tune_restore.py

@@ -116,7 +116,7 @@ class AutoInitTest(unittest.TestCase):
         _register_all()
 
 
-class AbstractWarmStartTest(object):
+class AbstractWarmStartTest:
     def setUp(self):
         ray.init(local_mode=True)
         self.tmpdir = tempfile.mkdtemp()

python/ray/tune/track/session.py

@@ -18,7 +18,7 @@ class _ReporterHook(Logger):
         return self.tune_reporter(**metrics)
 
 
-class TrackSession(object):
+class TrackSession:
     """Manages results for a single session.
 
     Represents a single Trial in an experiment.

python/ray/tune/trainable.py

@@ -29,7 +29,7 @@ logger = logging.getLogger(__name__)
 SETUP_TIME_THRESHOLD = 10
 
 
-class Trainable(object):
+class Trainable:
     """Abstract class for trainable models, functions, etc.
 
     A call to ``train()`` on a trainable will execute one logical iteration of

python/ray/tune/trial.py

@@ -32,7 +32,7 @@ def date_str():
     return datetime.today().strftime("%Y-%m-%d_%H-%M-%S")
 
 
-class Location(object):
+class Location:
     """Describes the location at which Trial is placed to run."""
 
     def __init__(self, hostname=None, pid=None):
@@ -48,7 +48,7 @@ class Location(object):
             return "{}:{}".format(self.hostname, self.pid)
 
 
-class ExportFormat(object):
+class ExportFormat:
     """Describes the format to export the trial Trainable.
 
     This may correspond to different file formats based on the
@@ -73,7 +73,7 @@ class ExportFormat(object):
                                 export_formats[i])
 
 
-class Trial(object):
+class Trial:
     """A trial object holds the state for one model training run.
 
     Trials are themselves managed by the TrialRunner class, which implements

python/ray/tune/trial_executor.py

@@ -11,7 +11,7 @@ from ray.tune.error import TuneError
 logger = logging.getLogger(__name__)
 
 
-class TrialExecutor(object):
+class TrialExecutor:
     """Manages platform-specific details such as resource handling
     and starting/stopping trials.
     """

python/ray/tune/trial_runner.py

@@ -77,7 +77,7 @@ class _TuneFunctionDecoder(json.JSONDecoder):
         return cloudpickle.loads(hex_to_binary(obj["value"]))
 
 
-class TrialRunner(object):
+class TrialRunner:
     """A TrialRunner implements the event loop for scheduling trials on Ray.
 
     Example:

python/ray/tune/util.py

@@ -111,7 +111,7 @@ def get_pinned_object(pinned_id):
     return ray.get(pinned_id)
 
 
-class warn_if_slow(object):
+class warn_if_slow:
     """Prints a warning if a given operation is slower than 100ms.
 
     Example:

python/ray/tune/web_server.py

@@ -24,7 +24,7 @@ except ImportError:
                      "Be sure to install it on the client side.")
 
 
-class TuneClient(object):
+class TuneClient:
     """Client to interact with an ongoing Tune experiment.
 
     Requires a TuneServer to have started running.

python/ray/worker.py

@@ -72,7 +72,7 @@ except ImportError:
     setproctitle = None
 
 
-class ActorCheckpointInfo(object):
+class ActorCheckpointInfo:
     """Information used to maintain actor checkpoints."""
 
     __slots__ = [
@@ -91,7 +91,7 @@ class ActorCheckpointInfo(object):
         self.checkpoint_ids = checkpoint_ids
 
 
-class Worker(object):
+class Worker:
     """A class used to define the control flow of a worker process.
 
     Note:
@@ -1707,7 +1707,7 @@ def remote(*args, **kwargs):
             return 1
 
         @ray.remote
-        class Foo(object):
+        class Foo:
             def method(self):
                 return 1
 
@@ -1743,7 +1743,7 @@ def remote(*args, **kwargs):
             return 1, 2
 
         @ray.remote(num_cpus=2, resources={"CustomResource": 1})
-        class Foo(object):
+        class Foo:
             def method(self):
                 return 1
 
@@ -1759,7 +1759,7 @@ def remote(*args, **kwargs):
         g = f.options(num_gpus=2, max_calls=None)
 
         @ray.remote(num_cpus=2, resources={"CustomResource": 1})
-        class Foo(object):
+        class Foo:
             def method(self):
                 return 1
         Bar = Foo.options(num_cpus=1, resources=None)

rllib/agents/a3c/a3c_tf_policy.py

@@ -17,7 +17,7 @@ from ray.rllib.utils import try_import_tf
 tf = try_import_tf()
 
 
-class A3CLoss(object):
+class A3CLoss:
     def __init__(self,
                  action_dist,
                  actions,
@@ -73,7 +73,7 @@ def add_value_function_fetch(policy):
     return {SampleBatch.VF_PREDS: policy.model.value_function()}
 
 
-class ValueNetworkMixin(object):
+class ValueNetworkMixin:
     def __init__(self):
         @make_tf_callable(self.get_session())
         def value(ob, prev_action, prev_reward, *state):
@@ -94,8 +94,7 @@ def stats(policy, train_batch):
         "cur_lr": tf.cast(policy.cur_lr, tf.float64),
         "policy_loss": policy.loss.pi_loss,
         "policy_entropy": policy.loss.entropy,
-        "var_gnorm": tf.global_norm(
-            list(policy.model.trainable_variables())),
+        "var_gnorm": tf.global_norm(list(policy.model.trainable_variables())),
         "vf_loss": policy.loss.vf_loss,
     }
 

rllib/agents/a3c/a3c_torch_policy.py

@@ -69,7 +69,7 @@ def torch_optimizer(policy, config):
     return torch.optim.Adam(policy.model.parameters(), lr=config["lr"])
 
 
-class ValueNetworkMixin(object):
+class ValueNetworkMixin:
     def _value(self, obs):
         obs = torch.from_numpy(obs).float().unsqueeze(0).to(self.device)
         _ = self.model({"obs": obs}, [], [1])

rllib/agents/ars/ars.py

@@ -55,7 +55,7 @@ def create_shared_noise(count):
     return noise
 
 
-class SharedNoiseTable(object):
+class SharedNoiseTable:
     def __init__(self, noise):
         self.noise = noise
         assert self.noise.dtype == np.float32
@@ -72,7 +72,7 @@ class SharedNoiseTable(object):
 
 
 @ray.remote
-class Worker(object):
+class Worker:
     def __init__(self, config, env_creator, noise, min_task_runtime=0.2):
         self.min_task_runtime = min_task_runtime
         self.config = config

rllib/agents/ars/optimizers.py

@@ -8,7 +8,7 @@ from __future__ import print_function
 import numpy as np
 
 
-class Optimizer(object):
+class Optimizer:
     def __init__(self, policy):
         self.policy = policy
         self.dim = policy.num_params

rllib/agents/ars/policies.py

@@ -56,7 +56,7 @@ def rollout(policy, env, timestep_limit=None, add_noise=False, offset=0):
     return rews, t
 
 
-class GenericPolicy(object):
+class GenericPolicy:
     def __init__(self,
                  sess,
                  action_space,

rllib/agents/ddpg/ddpg_policy.py

@@ -32,7 +32,7 @@ TWIN_Q_TARGET_SCOPE = "twin_target_critic"
 PRIO_WEIGHTS = "weights"
 
 
-class DDPGPostprocessing(object):
+class DDPGPostprocessing:
     """Implements n-step learning and param noise adjustments."""
 
     @override(Policy)