Python 2 compatibility. (#5887)

python/ray/autoscaler/autoscaler.py

@@ -354,7 +354,7 @@ class NodeLauncher(threading.Thread):
         logger.info(prefix + " {}".format(statement))
 
 
-class ConcurrentCounter():
+class ConcurrentCounter(object):
     def __init__(self):
         self._value = 0
         self._lock = threading.Lock()

python/ray/autoscaler/log_timer.py

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

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

@@ -9,7 +9,7 @@ from ray.experimental.serve.metric import MetricMonitor
 @pytest.fixture(scope="session")
 def start_target_actor(ray_instance):
     @ray.remote
-    class Target():
+    class Target(object):
         def __init__(self):
             self.counter_value = 0
 

python/ray/tune/log_sync.py

@@ -41,7 +41,7 @@ def log_sync_template():
             ).format(ssh_key=quote(ssh_key))
 
 
-class NodeSyncMixin():
+class NodeSyncMixin(object):
     """Mixin for syncing files to/from a remote dir to a local dir."""
 
     def __init__(self):

python/ray/tune/schedulers/hyperband.py

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

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():
+class Capturing(object):
     def __enter__(self):
         self._stdout = sys.stdout
         sys.stdout = self._stringio = StringIO()