Internal change

PiperOrigin-RevId: 321883870

orbit/__init__.py

+# Lint as: python3
 # Copyright 2020 The Orbit Authors. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -12,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # ==============================================================================
+"""Orbit package definition."""
 
 from orbit import utils
 from orbit.controller import Controller

orbit/controller.py

+# Lint as: python3
 # Copyright 2020 The Orbit Authors. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -14,14 +15,8 @@
 # ==============================================================================
 """A light weight utilities to train TF2 models."""
 
-from __future__ import absolute_import
-from __future__ import division
-# from __future__ import google_type_annotations
-from __future__ import print_function
-
 import time
 from typing import Callable, Optional, Text, Union
-
 from absl import logging
 from orbit import runner
 from orbit import utils
@@ -43,7 +38,7 @@ def _validate_interval(interval: Optional[int], steps_per_loop: Optional[int],
                          interval_name, interval, steps_per_loop))
 
 
-class Controller(object):
+class Controller:
   """Class that facilitates training and evaluation of models."""
 
   def __init__(
@@ -396,7 +391,7 @@ class Controller(object):
     return False
 
 
-class StepTimer(object):
+class StepTimer:
   """Utility class for measuring steps/second."""
 
   def __init__(self, step):

orbit/controller_test.py

+# Lint as: python3
 # Copyright 2020 The Orbit Authors. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -14,10 +15,6 @@
 # ==============================================================================
 """Tests for orbit.controller."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 from absl import logging
 from absl.testing import parameterized
@@ -203,7 +200,7 @@ class TestTrainerWithSummaries(standard_runner.StandardTrainer):
 class ControllerTest(tf.test.TestCase, parameterized.TestCase):
 
   def setUp(self):
-    super(ControllerTest, self).setUp()
+    super().setUp()
     self.model_dir = self.get_temp_dir()
 
   def test_no_checkpoint(self):

orbit/runner.py

+# Lint as: python3
 # Copyright 2020 The Orbit Authors. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -14,19 +15,12 @@
 # ==============================================================================
 """An abstraction that users can easily handle their custom training loops."""
 
-from __future__ import absolute_import
-from __future__ import division
-# from __future__ import google_type_annotations
-from __future__ import print_function
-
 import abc
 from typing import Dict, Optional, Text
-import six
 import tensorflow as tf
 
 
-@six.add_metaclass(abc.ABCMeta)
-class AbstractTrainer(tf.Module):
+class AbstractTrainer(tf.Module, metaclass=abc.ABCMeta):
   """An abstract class defining the APIs required for training."""
 
   @abc.abstractmethod
@@ -56,8 +50,7 @@ class AbstractTrainer(tf.Module):
     pass
 
 
-@six.add_metaclass(abc.ABCMeta)
-class AbstractEvaluator(tf.Module):
+class AbstractEvaluator(tf.Module, metaclass=abc.ABCMeta):
   """An abstract class defining the APIs required for evaluation."""
 
   @abc.abstractmethod

orbit/standard_runner.py

+# Lint as: python3
 # Copyright 2020 The Orbit Authors. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -14,21 +15,14 @@
 # ==============================================================================
 """An abstraction that users can easily handle their custom training loops."""
 
-from __future__ import absolute_import
-from __future__ import division
-# from __future__ import google_type_annotations
-from __future__ import print_function
-
 import abc
 from typing import Any, Dict, Optional, Text
 from orbit import runner
 from orbit import utils
-import six
 import tensorflow as tf
 
 
-@six.add_metaclass(abc.ABCMeta)
-class StandardTrainer(runner.AbstractTrainer):
+class StandardTrainer(runner.AbstractTrainer, metaclass=abc.ABCMeta):
   """Implements the standard functionality of AbstractTrainer APIs."""
 
   def __init__(self,
@@ -145,8 +139,7 @@ class StandardTrainer(runner.AbstractTrainer):
     self._train_iter = None
 
 
-@six.add_metaclass(abc.ABCMeta)
-class StandardEvaluator(runner.AbstractEvaluator):
+class StandardEvaluator(runner.AbstractEvaluator, metaclass=abc.ABCMeta):
   """Implements the standard functionality of AbstractEvaluator APIs."""
 
   def __init__(self, eval_dataset, use_tf_function=True):

orbit/standard_runner_test.py

+# Lint as: python3
 # Copyright 2020 The Orbit Authors. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");

orbit/utils.py

+# Lint as: python3
 # Copyright 2020 The Orbit Authors. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -14,18 +15,12 @@
 # ==============================================================================
 """Some layered modules/functions to help users writing custom training loop."""
 
-from __future__ import absolute_import
-from __future__ import division
-# from __future__ import google_type_annotations
-from __future__ import print_function
-
 import abc
 import contextlib
 import functools
 import inspect
 
 import numpy as np
-import six
 import tensorflow as tf
 
 
@@ -132,10 +127,7 @@ def make_distributed_dataset(strategy, dataset_or_fn, *args, **kwargs):
     # names, pass `ctx` as the value of `input_context` when calling
     # `dataset_or_fn`. Otherwise `ctx` will not be used when calling
     # `dataset_or_fn`.
-    if six.PY3:
-      argspec = inspect.getfullargspec(dataset_or_fn)
-    else:
-      argspec = inspect.getargspec(dataset_or_fn)  # pylint: disable=deprecated-method
+    argspec = inspect.getfullargspec(dataset_or_fn)
     args_names = argspec.args
 
     if "input_context" in args_names:
@@ -146,7 +138,7 @@ def make_distributed_dataset(strategy, dataset_or_fn, *args, **kwargs):
   return strategy.experimental_distribute_datasets_from_function(dataset_fn)
 
 
-class SummaryManager(object):
+class SummaryManager:
   """A class manages writing summaries."""
 
   def __init__(self, summary_dir, summary_fn, global_step=None):
@@ -201,8 +193,7 @@ class SummaryManager(object):
         self._summary_fn(name, tensor, step=self._global_step)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class Trigger(object):
+class Trigger(metaclass=abc.ABCMeta):
   """An abstract class representing a "trigger" for some event."""
 
   @abc.abstractmethod
@@ -263,7 +254,7 @@ class IntervalTrigger(Trigger):
     self._last_trigger_value = 0
 
 
-class EpochHelper(object):
+class EpochHelper:
   """A Helper class to handle epochs in Customized Training Loop."""
 
   def __init__(self, epoch_steps, global_step):