diff --git a/ci/jenkins_tests/miscellaneous/large_memory_test.py b/ci/jenkins_tests/miscellaneous/large_memory_test.py
index 9421c15b0..adfce498a 100644
--- a/ci/jenkins_tests/miscellaneous/large_memory_test.py
+++ b/ci/jenkins_tests/miscellaneous/large_memory_test.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 import ray
diff --git a/ci/jenkins_tests/miscellaneous/test_wait_hanging.py b/ci/jenkins_tests/miscellaneous/test_wait_hanging.py
index 911c5979f..7be648a6a 100644
--- a/ci/jenkins_tests/miscellaneous/test_wait_hanging.py
+++ b/ci/jenkins_tests/miscellaneous/test_wait_hanging.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 
 
diff --git a/ci/long_running_tests/workloads/actor_deaths.py b/ci/long_running_tests/workloads/actor_deaths.py
index 795960b93..e05489706 100644
--- a/ci/long_running_tests/workloads/actor_deaths.py
+++ b/ci/long_running_tests/workloads/actor_deaths.py
@@ -1,9 +1,5 @@
 # This workload tests repeatedly killing actors and submitting tasks to them.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import sys
 import time
diff --git a/ci/long_running_tests/workloads/apex.py b/ci/long_running_tests/workloads/apex.py
index 6b306f68e..7d33b89fb 100644
--- a/ci/long_running_tests/workloads/apex.py
+++ b/ci/long_running_tests/workloads/apex.py
@@ -1,9 +1,5 @@
 # This workload tests running APEX
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.cluster_utils import Cluster
 from ray.tune import run_experiments
diff --git a/ci/long_running_tests/workloads/impala.py b/ci/long_running_tests/workloads/impala.py
index 56f1ce4d0..1e54fbc19 100644
--- a/ci/long_running_tests/workloads/impala.py
+++ b/ci/long_running_tests/workloads/impala.py
@@ -1,9 +1,5 @@
 # This workload tests running IMPALA with remote envs
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.tune import run_experiments
 from ray.cluster_utils import Cluster
diff --git a/ci/long_running_tests/workloads/many_actor_tasks.py b/ci/long_running_tests/workloads/many_actor_tasks.py
index e4b17dce9..a2875d8ee 100644
--- a/ci/long_running_tests/workloads/many_actor_tasks.py
+++ b/ci/long_running_tests/workloads/many_actor_tasks.py
@@ -1,9 +1,5 @@
 # This workload tests submitting many actor methods.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import time
 
 import numpy as np
diff --git a/ci/long_running_tests/workloads/many_drivers.py b/ci/long_running_tests/workloads/many_drivers.py
index 2e540e046..9ceb558dc 100644
--- a/ci/long_running_tests/workloads/many_drivers.py
+++ b/ci/long_running_tests/workloads/many_drivers.py
@@ -1,9 +1,5 @@
 # This workload tests many drivers using the same cluster.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import time
 
 import ray
diff --git a/ci/long_running_tests/workloads/many_tasks.py b/ci/long_running_tests/workloads/many_tasks.py
index 0f05b9826..ca2c36cba 100644
--- a/ci/long_running_tests/workloads/many_tasks.py
+++ b/ci/long_running_tests/workloads/many_tasks.py
@@ -1,9 +1,5 @@
 # This workload tests submitting and getting many tasks over and over.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import time
 
 import numpy as np
diff --git a/ci/long_running_tests/workloads/node_failures.py b/ci/long_running_tests/workloads/node_failures.py
index 0770e65ff..87863229e 100644
--- a/ci/long_running_tests/workloads/node_failures.py
+++ b/ci/long_running_tests/workloads/node_failures.py
@@ -1,9 +1,5 @@
 # This workload tests repeatedly killing a node and adding a new node.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import time
 
 import ray
diff --git a/ci/long_running_tests/workloads/pbt.py b/ci/long_running_tests/workloads/pbt.py
index 05298f198..69b87f997 100644
--- a/ci/long_running_tests/workloads/pbt.py
+++ b/ci/long_running_tests/workloads/pbt.py
@@ -1,9 +1,5 @@
 # This workload tests running PBT
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.tune import run_experiments
 from ray.tune.schedulers import PopulationBasedTraining
diff --git a/ci/performance_tests/test_performance.py b/ci/performance_tests/test_performance.py
index c020343f1..006cf4f93 100644
--- a/ci/performance_tests/test_performance.py
+++ b/ci/performance_tests/test_performance.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import logging
 import numpy as np
diff --git a/ci/stress_tests/test_dead_actors.py b/ci/stress_tests/test_dead_actors.py
index 3a9a5a07a..3d0c05dac 100644
--- a/ci/stress_tests/test_dead_actors.py
+++ b/ci/stress_tests/test_dead_actors.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 import sys
diff --git a/ci/stress_tests/test_many_tasks.py b/ci/stress_tests/test_many_tasks.py
index 4efa25ca7..14428fbdc 100644
--- a/ci/stress_tests/test_many_tasks.py
+++ b/ci/stress_tests/test_many_tasks.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import logging
 import time
diff --git a/doc/examples/cython/cython_examples/__init__.py b/doc/examples/cython/cython_examples/__init__.py
index a11c53c0c..0f4ba110e 100644
--- a/doc/examples/cython/cython_examples/__init__.py
+++ b/doc/examples/cython/cython_examples/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from .cython_simple import simple_func, fib, fib_int, \
         fib_cpdef, fib_cdef, simple_class
 from .masked_log import masked_log
diff --git a/doc/examples/cython/cython_main.py b/doc/examples/cython/cython_main.py
index 296b3f67c..aecac3c51 100644
--- a/doc/examples/cython/cython_main.py
+++ b/doc/examples/cython/cython_main.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 import click
 import inspect
diff --git a/doc/examples/cython/setup.py b/doc/examples/cython/setup.py
index 86021ea6d..38f2b1d9d 100644
--- a/doc/examples/cython/setup.py
+++ b/doc/examples/cython/setup.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 from setuptools import setup
 from Cython.Build import cythonize
diff --git a/doc/examples/lbfgs/driver.py b/doc/examples/lbfgs/driver.py
index 0dfd81883..d4964cd02 100644
--- a/doc/examples/lbfgs/driver.py
+++ b/doc/examples/lbfgs/driver.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import os
 import scipy.optimize
diff --git a/doc/examples/newsreader/server.py b/doc/examples/newsreader/server.py
index e30f8269c..97222d620 100644
--- a/doc/examples/newsreader/server.py
+++ b/doc/examples/newsreader/server.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import atoma
 from flask import Flask, jsonify, request
 from flask_cors import CORS
diff --git a/doc/kubernetes/example.py b/doc/kubernetes/example.py
index ff2bbe0f4..a6b0dd059 100644
--- a/doc/kubernetes/example.py
+++ b/doc/kubernetes/example.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import Counter
 import os
 import sys
diff --git a/doc/yarn/example.py b/doc/yarn/example.py
index 949e055dc..56e96bf32 100644
--- a/doc/yarn/example.py
+++ b/doc/yarn/example.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import Counter
 import sys
 import time
diff --git a/java/modify_generated_java_flatbuffers_files.py b/java/modify_generated_java_flatbuffers_files.py
index 5bf62e56d..d33c8414d 100644
--- a/java/modify_generated_java_flatbuffers_files.py
+++ b/java/modify_generated_java_flatbuffers_files.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import sys
 """
diff --git a/java/test/src/main/resources/test_cross_language_invocation.py b/java/test/src/main/resources/test_cross_language_invocation.py
index e7f7aa1ed..0bc84c9f8 100644
--- a/java/test/src/main/resources/test_cross_language_invocation.py
+++ b/java/test/src/main/resources/test_cross_language_invocation.py
@@ -1,10 +1,6 @@
 # This file is used by CrossLanguageInvocationTest.java to test cross-language
 # invocation.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import six
 
 import ray
diff --git a/python/ray/__init__.py b/python/ray/__init__.py
index dee294665..42dc2e806 100644
--- a/python/ray/__init__.py
+++ b/python/ray/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 from os.path import dirname
 import sys
diff --git a/python/ray/actor.py b/python/ray/actor.py
index 0cd2f6057..691cafd81 100644
--- a/python/ray/actor.py
+++ b/python/ray/actor.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import inspect
 import logging
diff --git a/python/ray/autoscaler/autoscaler.py b/python/ray/autoscaler/autoscaler.py
index dd399b721..f28b1df9b 100644
--- a/python/ray/autoscaler/autoscaler.py
+++ b/python/ray/autoscaler/autoscaler.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import hashlib
 import json
diff --git a/python/ray/autoscaler/aws/config.py b/python/ray/autoscaler/aws/config.py
index 5fbadfdfa..7df4c11a1 100644
--- a/python/ray/autoscaler/aws/config.py
+++ b/python/ray/autoscaler/aws/config.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from distutils.version import StrictVersion
 import json
 import os
diff --git a/python/ray/autoscaler/aws/node_provider.py b/python/ray/autoscaler/aws/node_provider.py
index 33a6a4ac6..0d275d22d 100644
--- a/python/ray/autoscaler/aws/node_provider.py
+++ b/python/ray/autoscaler/aws/node_provider.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import random
 import threading
 from collections import defaultdict
diff --git a/python/ray/autoscaler/commands.py b/python/ray/autoscaler/commands.py
index 0961642ad..04dc8a7a8 100644
--- a/python/ray/autoscaler/commands.py
+++ b/python/ray/autoscaler/commands.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import hashlib
 import json
diff --git a/python/ray/autoscaler/docker.py b/python/ray/autoscaler/docker.py
index 8088e5387..b3d5f7789 100644
--- a/python/ray/autoscaler/docker.py
+++ b/python/ray/autoscaler/docker.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import logging
 try:  # py3
diff --git a/python/ray/autoscaler/gcp/config.py b/python/ray/autoscaler/gcp/config.py
index ba5026700..4071d48dc 100644
--- a/python/ray/autoscaler/gcp/config.py
+++ b/python/ray/autoscaler/gcp/config.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import logging
 import time
diff --git a/python/ray/autoscaler/gcp/node_provider.py b/python/ray/autoscaler/gcp/node_provider.py
index 7d6afa016..af48f2334 100644
--- a/python/ray/autoscaler/gcp/node_provider.py
+++ b/python/ray/autoscaler/gcp/node_provider.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from uuid import uuid4
 from threading import RLock
 import time
diff --git a/python/ray/autoscaler/kubernetes/__init__.py b/python/ray/autoscaler/kubernetes/__init__.py
index b6328f6e2..4dd701fa1 100644
--- a/python/ray/autoscaler/kubernetes/__init__.py
+++ b/python/ray/autoscaler/kubernetes/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import kubernetes
 from kubernetes.config.config_exception import ConfigException
 
diff --git a/python/ray/autoscaler/kubernetes/config.py b/python/ray/autoscaler/kubernetes/config.py
index a16eb33a0..b0a9452ce 100644
--- a/python/ray/autoscaler/kubernetes/config.py
+++ b/python/ray/autoscaler/kubernetes/config.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from kubernetes import client
diff --git a/python/ray/autoscaler/kubernetes/node_provider.py b/python/ray/autoscaler/kubernetes/node_provider.py
index 69320f9ca..a65f7e823 100644
--- a/python/ray/autoscaler/kubernetes/node_provider.py
+++ b/python/ray/autoscaler/kubernetes/node_provider.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from ray.autoscaler.kubernetes import core_api, log_prefix
diff --git a/python/ray/autoscaler/local/config.py b/python/ray/autoscaler/local/config.py
index ab73bbfa2..e801064d7 100644
--- a/python/ray/autoscaler/local/config.py
+++ b/python/ray/autoscaler/local/config.py
@@ -1,7 +1,2 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-
 def bootstrap_local(config):
     return config
diff --git a/python/ray/autoscaler/local/node_provider.py b/python/ray/autoscaler/local/node_provider.py
index e4f9fc8bc..b9961f9f7 100644
--- a/python/ray/autoscaler/local/node_provider.py
+++ b/python/ray/autoscaler/local/node_provider.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from filelock import FileLock
 from threading import RLock
 import json
diff --git a/python/ray/autoscaler/log_timer.py b/python/ray/autoscaler/log_timer.py
index 723d7a71c..2ad9dc18e 100644
--- a/python/ray/autoscaler/log_timer.py
+++ b/python/ray/autoscaler/log_timer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import datetime
 import logging
 
diff --git a/python/ray/autoscaler/node_provider.py b/python/ray/autoscaler/node_provider.py
index d8953e530..92dec4073 100644
--- a/python/ray/autoscaler/node_provider.py
+++ b/python/ray/autoscaler/node_provider.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import importlib
 import logging
 import os
diff --git a/python/ray/autoscaler/tags.py b/python/ray/autoscaler/tags.py
index d96f542ee..fca372281 100644
--- a/python/ray/autoscaler/tags.py
+++ b/python/ray/autoscaler/tags.py
@@ -1,9 +1,5 @@
 """The Ray autoscaler uses tags/labels to associate metadata with instances."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 # Tag for the name of the node
 TAG_RAY_NODE_NAME = "ray-node-name"
 
diff --git a/python/ray/autoscaler/updater.py b/python/ray/autoscaler/updater.py
index f200fe1f8..cc1899b67 100644
--- a/python/ray/autoscaler/updater.py
+++ b/python/ray/autoscaler/updater.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 try:  # py3
     from shlex import quote
 except ImportError:  # py2
diff --git a/python/ray/cluster_utils.py b/python/ray/cluster_utils.py
index 0c7988f80..d31891e39 100644
--- a/python/ray/cluster_utils.py
+++ b/python/ray/cluster_utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import time
 
diff --git a/python/ray/dashboard/dashboard.py b/python/ray/dashboard/dashboard.py
index 29991a211..47128064a 100644
--- a/python/ray/dashboard/dashboard.py
+++ b/python/ray/dashboard/dashboard.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 try:
     import aiohttp.web
 except ImportError:
diff --git a/python/ray/experimental/__init__.py b/python/ray/experimental/__init__.py
index f31b58249..1b214d6df 100644
--- a/python/ray/experimental/__init__.py
+++ b/python/ray/experimental/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from .gcs_flush_policy import (set_flushing_policy, GcsFlushPolicy,
                                SimpleGcsFlushPolicy)
 from .named_actors import get_actor, register_actor
diff --git a/python/ray/experimental/actor_pool.py b/python/ray/experimental/actor_pool.py
index 4deef58f5..4e5f06406 100644
--- a/python/ray/experimental/actor_pool.py
+++ b/python/ray/experimental/actor_pool.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 
 
diff --git a/python/ray/experimental/api.py b/python/ray/experimental/api.py
index ba396d8d6..24f8aa0c0 100644
--- a/python/ray/experimental/api.py
+++ b/python/ray/experimental/api.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 import numpy as np
 
diff --git a/python/ray/experimental/array/distributed/__init__.py b/python/ray/experimental/array/distributed/__init__.py
index df0f8f599..98f19efae 100644
--- a/python/ray/experimental/array/distributed/__init__.py
+++ b/python/ray/experimental/array/distributed/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from . import random
 from . import linalg
 from .core import (BLOCK_SIZE, DistArray, assemble, zeros, ones, copy, eye,
diff --git a/python/ray/experimental/array/distributed/core.py b/python/ray/experimental/array/distributed/core.py
index af758d528..f296d21f4 100644
--- a/python/ray/experimental/array/distributed/core.py
+++ b/python/ray/experimental/array/distributed/core.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import ray.experimental.array.remote as ra
 import ray
diff --git a/python/ray/experimental/array/distributed/linalg.py b/python/ray/experimental/array/distributed/linalg.py
index 8bf45fe6b..0b3f4ecf5 100644
--- a/python/ray/experimental/array/distributed/linalg.py
+++ b/python/ray/experimental/array/distributed/linalg.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import ray.experimental.array.remote as ra
 import ray
diff --git a/python/ray/experimental/array/distributed/random.py b/python/ray/experimental/array/distributed/random.py
index a946df90a..cb96591af 100644
--- a/python/ray/experimental/array/distributed/random.py
+++ b/python/ray/experimental/array/distributed/random.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import ray.experimental.array.remote as ra
 import ray
diff --git a/python/ray/experimental/array/remote/__init__.py b/python/ray/experimental/array/remote/__init__.py
index 1f2e4429f..ef212798d 100644
--- a/python/ray/experimental/array/remote/__init__.py
+++ b/python/ray/experimental/array/remote/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from . import random
 from . import linalg
 from .core import (zeros, zeros_like, ones, eye, dot, vstack, hstack, subarray,
diff --git a/python/ray/experimental/array/remote/core.py b/python/ray/experimental/array/remote/core.py
index 2484b848b..f4572da82 100644
--- a/python/ray/experimental/array/remote/core.py
+++ b/python/ray/experimental/array/remote/core.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import ray
 
diff --git a/python/ray/experimental/array/remote/linalg.py b/python/ray/experimental/array/remote/linalg.py
index 99c862b2e..bdde3a17b 100644
--- a/python/ray/experimental/array/remote/linalg.py
+++ b/python/ray/experimental/array/remote/linalg.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import ray
 
diff --git a/python/ray/experimental/array/remote/random.py b/python/ray/experimental/array/remote/random.py
index 64346c34a..581051b36 100644
--- a/python/ray/experimental/array/remote/random.py
+++ b/python/ray/experimental/array/remote/random.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import ray
 
diff --git a/python/ray/experimental/gcs_flush_policy.py b/python/ray/experimental/gcs_flush_policy.py
index 36e5ae701..00d9e85fe 100644
--- a/python/ray/experimental/gcs_flush_policy.py
+++ b/python/ray/experimental/gcs_flush_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import time
 
diff --git a/python/ray/experimental/internal_kv.py b/python/ray/experimental/internal_kv.py
index f2a19450c..df670547d 100644
--- a/python/ray/experimental/internal_kv.py
+++ b/python/ray/experimental/internal_kv.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 
 _local = {}  # dict for local mode
diff --git a/python/ray/experimental/multiprocessing/pool.py b/python/ray/experimental/multiprocessing/pool.py
index e0e6b06ec..4a87a6798 100644
--- a/python/ray/experimental/multiprocessing/pool.py
+++ b/python/ray/experimental/multiprocessing/pool.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from multiprocessing import TimeoutError
 import os
 import time
diff --git a/python/ray/experimental/named_actors.py b/python/ray/experimental/named_actors.py
index 40db19141..e74e31bba 100644
--- a/python/ray/experimental/named_actors.py
+++ b/python/ray/experimental/named_actors.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 import ray.cloudpickle as pickle
 from ray.experimental.internal_kv import _internal_kv_get, _internal_kv_put
diff --git a/python/ray/experimental/no_return.py b/python/ray/experimental/no_return.py
index e9dc0e754..deaed5e42 100644
--- a/python/ray/experimental/no_return.py
+++ b/python/ray/experimental/no_return.py
@@ -1,8 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-
 class NoReturn:
     """Do not store the return value in the object store.
 
diff --git a/python/ray/experimental/queue.py b/python/ray/experimental/queue.py
index 0102e36d9..01f4fda3e 100644
--- a/python/ray/experimental/queue.py
+++ b/python/ray/experimental/queue.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import deque
 import time
 
diff --git a/python/ray/experimental/sgd/examples/cifar_pytorch_example.py b/python/ray/experimental/sgd/examples/cifar_pytorch_example.py
index 1a2622a9e..1e55c9b91 100644
--- a/python/ray/experimental/sgd/examples/cifar_pytorch_example.py
+++ b/python/ray/experimental/sgd/examples/cifar_pytorch_example.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import torch
 import torch.nn as nn
diff --git a/python/ray/experimental/sgd/examples/cifar_tf_example.py b/python/ray/experimental/sgd/examples/cifar_tf_example.py
index b95021589..6d0e61a13 100644
--- a/python/ray/experimental/sgd/examples/cifar_tf_example.py
+++ b/python/ray/experimental/sgd/examples/cifar_tf_example.py
@@ -4,10 +4,6 @@
 It gets to 75% validation accuracy in 25 epochs, and 79% after 50 epochs.
 (it"s still underfitting at that point, though).
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 
 from tensorflow.keras.datasets import cifar10
diff --git a/python/ray/experimental/sgd/examples/tensorflow_train_example.py b/python/ray/experimental/sgd/examples/tensorflow_train_example.py
index 96c0e880f..b95e59a84 100644
--- a/python/ray/experimental/sgd/examples/tensorflow_train_example.py
+++ b/python/ray/experimental/sgd/examples/tensorflow_train_example.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import tensorflow as tf
 from tensorflow.keras.models import Sequential
diff --git a/python/ray/experimental/sgd/examples/train_example.py b/python/ray/experimental/sgd/examples/train_example.py
index 242091858..a527e8318 100644
--- a/python/ray/experimental/sgd/examples/train_example.py
+++ b/python/ray/experimental/sgd/examples/train_example.py
@@ -8,10 +8,6 @@ in the documentation.
 
 # yapf: disable
 # __torch_train_example__
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import numpy as np
 import torch
diff --git a/python/ray/experimental/sgd/examples/tune_example.py b/python/ray/experimental/sgd/examples/tune_example.py
index 93960652d..1fd8264e4 100644
--- a/python/ray/experimental/sgd/examples/tune_example.py
+++ b/python/ray/experimental/sgd/examples/tune_example.py
@@ -8,10 +8,6 @@ in the documentation.
 """
 
 # __torch_tune_example__
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import torch
 import torch.nn as nn
diff --git a/python/ray/experimental/sgd/pytorch/__init__.py b/python/ray/experimental/sgd/pytorch/__init__.py
index 06ab7c4fd..335437a14 100644
--- a/python/ray/experimental/sgd/pytorch/__init__.py
+++ b/python/ray/experimental/sgd/pytorch/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.experimental.sgd.pytorch.pytorch_trainer import (PyTorchTrainer,
                                                           PyTorchTrainable)
 
diff --git a/python/ray/experimental/sgd/pytorch/distributed_pytorch_runner.py b/python/ray/experimental/sgd/pytorch/distributed_pytorch_runner.py
index 77be62cb5..a6cbda9d4 100644
--- a/python/ray/experimental/sgd/pytorch/distributed_pytorch_runner.py
+++ b/python/ray/experimental/sgd/pytorch/distributed_pytorch_runner.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 from filelock import FileLock
 import logging
diff --git a/python/ray/experimental/sgd/pytorch/examples/dcgan.py b/python/ray/experimental/sgd/pytorch/examples/dcgan.py
index bad3eeccb..b5ba24ff8 100644
--- a/python/ray/experimental/sgd/pytorch/examples/dcgan.py
+++ b/python/ray/experimental/sgd/pytorch/examples/dcgan.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import os
 import torch
diff --git a/python/ray/experimental/sgd/pytorch/pytorch_runner.py b/python/ray/experimental/sgd/pytorch/pytorch_runner.py
index 4f3db0e22..a0c861d86 100644
--- a/python/ray/experimental/sgd/pytorch/pytorch_runner.py
+++ b/python/ray/experimental/sgd/pytorch/pytorch_runner.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 from filelock import FileLock
 import logging
diff --git a/python/ray/experimental/sgd/pytorch/pytorch_trainer.py b/python/ray/experimental/sgd/pytorch/pytorch_trainer.py
index 1eda6e56f..24ab04bf6 100644
--- a/python/ray/experimental/sgd/pytorch/pytorch_trainer.py
+++ b/python/ray/experimental/sgd/pytorch/pytorch_trainer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import os
 import torch
diff --git a/python/ray/experimental/sgd/pytorch/utils.py b/python/ray/experimental/sgd/pytorch/utils.py
index 4e60df2a4..84ad160af 100644
--- a/python/ray/experimental/sgd/pytorch/utils.py
+++ b/python/ray/experimental/sgd/pytorch/utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import time
 import torch
diff --git a/python/ray/experimental/sgd/tests/test_pytorch.py b/python/ray/experimental/sgd/tests/test_pytorch.py
index 5d5412397..cb3502a3f 100644
--- a/python/ray/experimental/sgd/tests/test_pytorch.py
+++ b/python/ray/experimental/sgd/tests/test_pytorch.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import pytest
 import tempfile
diff --git a/python/ray/experimental/sgd/tests/test_pytorch_runner.py b/python/ray/experimental/sgd/tests/test_pytorch_runner.py
index 13c5ee550..926101ad1 100644
--- a/python/ray/experimental/sgd/tests/test_pytorch_runner.py
+++ b/python/ray/experimental/sgd/tests/test_pytorch_runner.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import torch
 import torch.nn as nn
diff --git a/python/ray/experimental/sgd/tests/test_tensorflow.py b/python/ray/experimental/sgd/tests/test_tensorflow.py
index ff0850bf2..ce5f921fd 100644
--- a/python/ray/experimental/sgd/tests/test_tensorflow.py
+++ b/python/ray/experimental/sgd/tests/test_tensorflow.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import pytest
 import tempfile
diff --git a/python/ray/experimental/sgd/tf/__init__.py b/python/ray/experimental/sgd/tf/__init__.py
index 4c750ffe5..54701ab20 100644
--- a/python/ray/experimental/sgd/tf/__init__.py
+++ b/python/ray/experimental/sgd/tf/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.experimental.sgd.tf.tf_trainer import (TFTrainer, TFTrainable)
 
 __all__ = ["TFTrainer", "TFTrainable"]
diff --git a/python/ray/experimental/sgd/tf/tf_runner.py b/python/ray/experimental/sgd/tf/tf_runner.py
index 13903c073..379b59024 100644
--- a/python/ray/experimental/sgd/tf/tf_runner.py
+++ b/python/ray/experimental/sgd/tf/tf_runner.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import json
 import os
diff --git a/python/ray/experimental/sgd/tf/tf_trainer.py b/python/ray/experimental/sgd/tf/tf_trainer.py
index eed8f7f72..5f928e2d2 100644
--- a/python/ray/experimental/sgd/tf/tf_trainer.py
+++ b/python/ray/experimental/sgd/tf/tf_trainer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import os
 import logging
diff --git a/python/ray/experimental/sgd/utils.py b/python/ray/experimental/sgd/utils.py
index ce6ab7c6f..d2c66430b 100644
--- a/python/ray/experimental/sgd/utils.py
+++ b/python/ray/experimental/sgd/utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from contextlib import closing
 import numpy as np
 import socket
diff --git a/python/ray/experimental/signal.py b/python/ray/experimental/signal.py
index d7d4ef56b..477d7821e 100644
--- a/python/ray/experimental/signal.py
+++ b/python/ray/experimental/signal.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from collections import defaultdict
diff --git a/python/ray/experimental/test/async_test.py b/python/ray/experimental/test/async_test.py
index bdf45f77e..bbe706eb6 100644
--- a/python/ray/experimental/test/async_test.py
+++ b/python/ray/experimental/test/async_test.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import asyncio
 import time
 
diff --git a/python/ray/experimental/tf_utils.py b/python/ray/experimental/tf_utils.py
index 99c657562..bdddc6a96 100644
--- a/python/ray/experimental/tf_utils.py
+++ b/python/ray/experimental/tf_utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import deque, OrderedDict
 import numpy as np
 
diff --git a/python/ray/function_manager.py b/python/ray/function_manager.py
index ece7ccf96..6d9fe540c 100644
--- a/python/ray/function_manager.py
+++ b/python/ray/function_manager.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import dis
 import hashlib
 import importlib
diff --git a/python/ray/gcs_utils.py b/python/ray/gcs_utils.py
index 8cc90e7b7..22331c45f 100644
--- a/python/ray/gcs_utils.py
+++ b/python/ray/gcs_utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.core.generated.gcs_pb2 import (
     ActorCheckpointIdData,
     ActorTableData,
diff --git a/python/ray/import_thread.py b/python/ray/import_thread.py
index 364982cf2..3e2ebb50b 100644
--- a/python/ray/import_thread.py
+++ b/python/ray/import_thread.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import defaultdict
 import threading
 import traceback
diff --git a/python/ray/internal/__init__.py b/python/ray/internal/__init__.py
index e28ebcb2f..52485fb32 100644
--- a/python/ray/internal/__init__.py
+++ b/python/ray/internal/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.internal.internal_api import free
 
 __all__ = ["free"]
diff --git a/python/ray/internal/internal_api.py b/python/ray/internal/internal_api.py
index 0cc437ed9..a66cba1fb 100644
--- a/python/ray/internal/internal_api.py
+++ b/python/ray/internal/internal_api.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray.worker
 from ray import profiling
 
diff --git a/python/ray/local_mode_manager.py b/python/ray/local_mode_manager.py
index d86e75237..2b2bae292 100644
--- a/python/ray/local_mode_manager.py
+++ b/python/ray/local_mode_manager.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import traceback
 
diff --git a/python/ray/log_monitor.py b/python/ray/log_monitor.py
index 645200e93..764eb668f 100644
--- a/python/ray/log_monitor.py
+++ b/python/ray/log_monitor.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import errno
 import glob
diff --git a/python/ray/memory_monitor.py b/python/ray/memory_monitor.py
index 3928ecb8e..3ed3e6747 100644
--- a/python/ray/memory_monitor.py
+++ b/python/ray/memory_monitor.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import os
 import sys
diff --git a/python/ray/monitor.py b/python/ray/monitor.py
index 6658a708a..ca4ed2974 100644
--- a/python/ray/monitor.py
+++ b/python/ray/monitor.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import logging
 import os
diff --git a/python/ray/node.py b/python/ray/node.py
index d3d0dab60..5a7587725 100644
--- a/python/ray/node.py
+++ b/python/ray/node.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import atexit
 import collections
 import datetime
diff --git a/python/ray/parameter.py b/python/ray/parameter.py
index e88cacc60..f4750e71d 100644
--- a/python/ray/parameter.py
+++ b/python/ray/parameter.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 import numpy as np
diff --git a/python/ray/profiling.py b/python/ray/profiling.py
index b39410df5..c8732cf9b 100644
--- a/python/ray/profiling.py
+++ b/python/ray/profiling.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 
 
diff --git a/python/ray/projects/__init__.py b/python/ray/projects/__init__.py
index 20f031eda..82d7e0766 100644
--- a/python/ray/projects/__init__.py
+++ b/python/ray/projects/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.projects.projects import ProjectDefinition
 
 __all__ = [
diff --git a/python/ray/projects/projects.py b/python/ray/projects/projects.py
index 5c02bed0b..add817c87 100644
--- a/python/ray/projects/projects.py
+++ b/python/ray/projects/projects.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import copy
 import json
diff --git a/python/ray/projects/scripts.py b/python/ray/projects/scripts.py
index bd36a79bb..77374e0f4 100644
--- a/python/ray/projects/scripts.py
+++ b/python/ray/projects/scripts.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import click
 import copy
 import jsonschema
diff --git a/python/ray/ray_constants.py b/python/ray/ray_constants.py
index 7e091c0cc..f5fba1e17 100644
--- a/python/ray/ray_constants.py
+++ b/python/ray/ray_constants.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Ray constants used in the Python code."""
 
 import logging
diff --git a/python/ray/remote_function.py b/python/ray/remote_function.py
index c6ff8b276..a8b10e903 100644
--- a/python/ray/remote_function.py
+++ b/python/ray/remote_function.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 from functools import wraps
 
diff --git a/python/ray/reporter.py b/python/ray/reporter.py
index 65c44d617..1cdaa40e9 100644
--- a/python/ray/reporter.py
+++ b/python/ray/reporter.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import logging
 import json
diff --git a/python/ray/resource_spec.py b/python/ray/resource_spec.py
index 5fe4bb6fd..082b6fc37 100644
--- a/python/ray/resource_spec.py
+++ b/python/ray/resource_spec.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import math
 from collections import namedtuple
 import logging
diff --git a/python/ray/runtime_context.py b/python/ray/runtime_context.py
index dec103ca9..66ee92c2c 100644
--- a/python/ray/runtime_context.py
+++ b/python/ray/runtime_context.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray.worker
 
 
diff --git a/python/ray/scripts/scripts.py b/python/ray/scripts/scripts.py
index 7c986b1a9..84bf8f211 100644
--- a/python/ray/scripts/scripts.py
+++ b/python/ray/scripts/scripts.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import click
 from datetime import datetime
 import json
diff --git a/python/ray/serialization.py b/python/ray/serialization.py
index 2fbe13683..0e1666cfc 100644
--- a/python/ray/serialization.py
+++ b/python/ray/serialization.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import hashlib
 import io
 import logging
diff --git a/python/ray/services.py b/python/ray/services.py
index 4341ee4aa..be07a3cc9 100644
--- a/python/ray/services.py
+++ b/python/ray/services.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import json
 import logging
diff --git a/python/ray/setup-dev.py b/python/ray/setup-dev.py
index 70ae8fe8e..adbd0f0a9 100755
--- a/python/ray/setup-dev.py
+++ b/python/ray/setup-dev.py
@@ -1,10 +1,6 @@
 #!/usr/bin/env python
 """This script allows you to develop RLlib without needing to compile Ray."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import click
 import os
diff --git a/python/ray/signature.py b/python/ray/signature.py
index daaacf0b1..eaa2beb9e 100644
--- a/python/ray/signature.py
+++ b/python/ray/signature.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import namedtuple
 import funcsigs
 from funcsigs import Parameter
diff --git a/python/ray/state.py b/python/ray/state.py
index 8f6e50688..3c572e07e 100644
--- a/python/ray/state.py
+++ b/python/ray/state.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import defaultdict
 import json
 import logging
diff --git a/python/ray/test_utils.py b/python/ray/test_utils.py
index a3b937259..aac2f44d7 100644
--- a/python/ray/test_utils.py
+++ b/python/ray/test_utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import json
 import fnmatch
 import os
diff --git a/python/ray/tests/perf_integration_tests/test_perf_integration.py b/python/ray/tests/perf_integration_tests/test_perf_integration.py
index 7b7455255..3992a6cb7 100644
--- a/python/ray/tests/perf_integration_tests/test_perf_integration.py
+++ b/python/ray/tests/perf_integration_tests/test_perf_integration.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import pytest
 
diff --git a/python/ray/tests/py3_test.py b/python/ray/tests/py3_test.py
index 978776c6b..31addb6e2 100644
--- a/python/ray/tests/py3_test.py
+++ b/python/ray/tests/py3_test.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import asyncio
 import threading
 import pytest
diff --git a/python/ray/tests/test_actor.py b/python/ray/tests/test_actor.py
index 9c43c65fc..cd156667a 100644
--- a/python/ray/tests/test_actor.py
+++ b/python/ray/tests/test_actor.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import random
 import numpy as np
 import os
diff --git a/python/ray/tests/test_actor_failures.py b/python/ray/tests/test_actor_failures.py
index 67dc2cecf..8da0ba248 100644
--- a/python/ray/tests/test_actor_failures.py
+++ b/python/ray/tests/test_actor_failures.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import json
 import numpy as np
diff --git a/python/ray/tests/test_actor_pool.py b/python/ray/tests/test_actor_pool.py
index 1822991a3..1e186f92d 100644
--- a/python/ray/tests/test_actor_pool.py
+++ b/python/ray/tests/test_actor_pool.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import time
 import pytest
 
diff --git a/python/ray/tests/test_actor_resources.py b/python/ray/tests/test_actor_resources.py
index e919d6832..74ce411db 100644
--- a/python/ray/tests/test_actor_resources.py
+++ b/python/ray/tests/test_actor_resources.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import json
 import os
diff --git a/python/ray/tests/test_advanced.py b/python/ray/tests/test_advanced.py
index 262c6f8a4..935377d1c 100644
--- a/python/ray/tests/test_advanced.py
+++ b/python/ray/tests/test_advanced.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from concurrent.futures import ThreadPoolExecutor
 import json
 import logging
diff --git a/python/ray/tests/test_advanced_2.py b/python/ray/tests/test_advanced_2.py
index a9e50bd1f..4fcf38528 100644
--- a/python/ray/tests/test_advanced_2.py
+++ b/python/ray/tests/test_advanced_2.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import os
 import sys
diff --git a/python/ray/tests/test_advanced_3.py b/python/ray/tests/test_advanced_3.py
index 79c7f5a9e..598d22eb0 100644
--- a/python/ray/tests/test_advanced_3.py
+++ b/python/ray/tests/test_advanced_3.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import glob
 import logging
 import os
diff --git a/python/ray/tests/test_array.py b/python/ray/tests/test_array.py
index d50d394d7..62abafd1c 100644
--- a/python/ray/tests/test_array.py
+++ b/python/ray/tests/test_array.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from importlib import reload
 import numpy as np
 from numpy.testing import assert_equal, assert_almost_equal
diff --git a/python/ray/tests/test_autoscaler.py b/python/ray/tests/test_autoscaler.py
index ff23e70f9..47fe8bc2e 100644
--- a/python/ray/tests/test_autoscaler.py
+++ b/python/ray/tests/test_autoscaler.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import shutil
 import tempfile
 import threading
diff --git a/python/ray/tests/test_autoscaler_yaml.py b/python/ray/tests/test_autoscaler_yaml.py
index 6b2886890..6753e26f4 100644
--- a/python/ray/tests/test_autoscaler_yaml.py
+++ b/python/ray/tests/test_autoscaler_yaml.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import unittest
 import yaml
diff --git a/python/ray/tests/test_basic.py b/python/ray/tests/test_basic.py
index a4c765566..3781b2e7c 100644
--- a/python/ray/tests/test_basic.py
+++ b/python/ray/tests/test_basic.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import io
 import json
diff --git a/python/ray/tests/test_component_failures.py b/python/ray/tests/test_component_failures.py
index b4512cb74..416802035 100644
--- a/python/ray/tests/test_component_failures.py
+++ b/python/ray/tests/test_component_failures.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import signal
 import sys
diff --git a/python/ray/tests/test_component_failures_2.py b/python/ray/tests/test_component_failures_2.py
index e9f2c5a15..1a9821193 100644
--- a/python/ray/tests/test_component_failures_2.py
+++ b/python/ray/tests/test_component_failures_2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import json
 import os
 import signal
diff --git a/python/ray/tests/test_component_failures_3.py b/python/ray/tests/test_component_failures_3.py
index e8164881b..4fe52c1bd 100644
--- a/python/ray/tests/test_component_failures_3.py
+++ b/python/ray/tests/test_component_failures_3.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import sys
 import time
diff --git a/python/ray/tests/test_debug_tools.py b/python/ray/tests/test_debug_tools.py
index 44a0cc7ae..b42fe1e1a 100644
--- a/python/ray/tests/test_debug_tools.py
+++ b/python/ray/tests/test_debug_tools.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import subprocess
 import sys
diff --git a/python/ray/tests/test_dynres.py b/python/ray/tests/test_dynres.py
index 3dbdc0594..47984582b 100644
--- a/python/ray/tests/test_dynres.py
+++ b/python/ray/tests/test_dynres.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import time
 
diff --git a/python/ray/tests/test_failure.py b/python/ray/tests/test_failure.py
index b6d08f308..2a485207e 100644
--- a/python/ray/tests/test_failure.py
+++ b/python/ray/tests/test_failure.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import json
 import logging
 import os
diff --git a/python/ray/tests/test_global_state.py b/python/ray/tests/test_global_state.py
index 4089c538a..b93e3067b 100644
--- a/python/ray/tests/test_global_state.py
+++ b/python/ray/tests/test_global_state.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import pytest
 try:
     import pytest_timeout
diff --git a/python/ray/tests/test_iter.py b/python/ray/tests/test_iter.py
index 9b206fc8e..2e38011c1 100644
--- a/python/ray/tests/test_iter.py
+++ b/python/ray/tests/test_iter.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import time
 
 import ray
diff --git a/python/ray/tests/test_metrics.py b/python/ray/tests/test_metrics.py
index f3ed3f01a..563a2eaf1 100644
--- a/python/ray/tests/test_metrics.py
+++ b/python/ray/tests/test_metrics.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import grpc
 import psutil
diff --git a/python/ray/tests/test_microbenchmarks.py b/python/ray/tests/test_microbenchmarks.py
index ba8b6b7d1..8a2f1d4c7 100644
--- a/python/ray/tests/test_microbenchmarks.py
+++ b/python/ray/tests/test_microbenchmarks.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import pytest
 import time
 import numpy as np
diff --git a/python/ray/tests/test_mini.py b/python/ray/tests/test_mini.py
index 605b91056..f3f34c02e 100644
--- a/python/ray/tests/test_mini.py
+++ b/python/ray/tests/test_mini.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 
 test_values = [1, 1.0, "test", b"test", (0, 1), [0, 1], {0: 1}]
diff --git a/python/ray/tests/test_monitors.py b/python/ray/tests/test_monitors.py
index db2d458e3..f6296c8a5 100644
--- a/python/ray/tests/test_monitors.py
+++ b/python/ray/tests/test_monitors.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import multiprocessing
 import os
 import pytest
diff --git a/python/ray/tests/test_multi_node.py b/python/ray/tests/test_multi_node.py
index 4eb83a529..bcdb5afae 100644
--- a/python/ray/tests/test_multi_node.py
+++ b/python/ray/tests/test_multi_node.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import pytest
 import subprocess
diff --git a/python/ray/tests/test_multi_node_2.py b/python/ray/tests/test_multi_node_2.py
index fa986e1d8..0a49464a6 100644
--- a/python/ray/tests/test_multi_node_2.py
+++ b/python/ray/tests/test_multi_node_2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import pytest
 import time
diff --git a/python/ray/tests/test_multinode_failures.py b/python/ray/tests/test_multinode_failures.py
index c67a5bc85..9fa6f306e 100644
--- a/python/ray/tests/test_multinode_failures.py
+++ b/python/ray/tests/test_multinode_failures.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import json
 import os
 import signal
diff --git a/python/ray/tests/test_multinode_failures_2.py b/python/ray/tests/test_multinode_failures_2.py
index f03fee580..5bc111c10 100644
--- a/python/ray/tests/test_multinode_failures_2.py
+++ b/python/ray/tests/test_multinode_failures_2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import json
 import os
 import sys
diff --git a/python/ray/tests/test_multiprocessing.py b/python/ray/tests/test_multiprocessing.py
index 46cdba274..ad271d391 100644
--- a/python/ray/tests/test_multiprocessing.py
+++ b/python/ray/tests/test_multiprocessing.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import pytest
 import tempfile
diff --git a/python/ray/tests/test_node_manager.py b/python/ray/tests/test_node_manager.py
index b8afecc52..76d5d45d0 100644
--- a/python/ray/tests/test_node_manager.py
+++ b/python/ray/tests/test_node_manager.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.test_utils import run_string_as_driver
 
diff --git a/python/ray/tests/test_object_manager.py b/python/ray/tests/test_object_manager.py
index 186189f20..9e173fc82 100644
--- a/python/ray/tests/test_object_manager.py
+++ b/python/ray/tests/test_object_manager.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import defaultdict
 import json
 import multiprocessing
diff --git a/python/ray/tests/test_projects.py b/python/ray/tests/test_projects.py
index 7816aa964..a63cdb04b 100644
--- a/python/ray/tests/test_projects.py
+++ b/python/ray/tests/test_projects.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import jsonschema
 import os
 import pytest
diff --git a/python/ray/tests/test_queue.py b/python/ray/tests/test_queue.py
index 69c991554..247bcb2b1 100644
--- a/python/ray/tests/test_queue.py
+++ b/python/ray/tests/test_queue.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import pytest
 import time
 
diff --git a/python/ray/tests/test_ray_init.py b/python/ray/tests/test_ray_init.py
index cf3ecf4cd..cba08a6cd 100644
--- a/python/ray/tests/test_ray_init.py
+++ b/python/ray/tests/test_ray_init.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import pytest
 import redis
diff --git a/python/ray/tests/test_reference_counting.py b/python/ray/tests/test_reference_counting.py
index c8258848d..84dd4336f 100644
--- a/python/ray/tests/test_reference_counting.py
+++ b/python/ray/tests/test_reference_counting.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import json
 import copy
diff --git a/python/ray/tests/test_stress.py b/python/ray/tests/test_stress.py
index be43cfc8c..200788736 100644
--- a/python/ray/tests/test_stress.py
+++ b/python/ray/tests/test_stress.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import pytest
 import time
diff --git a/python/ray/tests/test_stress_failure.py b/python/ray/tests/test_stress_failure.py
index 1e5009dd0..3a4719f67 100644
--- a/python/ray/tests/test_stress_failure.py
+++ b/python/ray/tests/test_stress_failure.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import json
 import numpy as np
 import os
diff --git a/python/ray/tests/test_stress_sharded.py b/python/ray/tests/test_stress_sharded.py
index a55ba2503..814348e9b 100644
--- a/python/ray/tests/test_stress_sharded.py
+++ b/python/ray/tests/test_stress_sharded.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import os
 import pytest
diff --git a/python/ray/tests/test_tempfile.py b/python/ray/tests/test_tempfile.py
index a9f917340..e233a1897 100644
--- a/python/ray/tests/test_tempfile.py
+++ b/python/ray/tests/test_tempfile.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import shutil
 import time
diff --git a/python/ray/tests/test_tensorflow.py b/python/ray/tests/test_tensorflow.py
index 56f02fcc4..b26474c81 100644
--- a/python/ray/tests/test_tensorflow.py
+++ b/python/ray/tests/test_tensorflow.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from numpy.testing import assert_almost_equal
 import tensorflow.compat.v1 as tf
 
diff --git a/python/ray/tests/test_unreconstructable_errors.py b/python/ray/tests/test_unreconstructable_errors.py
index eb858c692..70c6ecc31 100644
--- a/python/ray/tests/test_unreconstructable_errors.py
+++ b/python/ray/tests/test_unreconstructable_errors.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import unittest
 
diff --git a/python/ray/tests/test_webui.py b/python/ray/tests/test_webui.py
index ea9701791..3e3e3a8b7 100644
--- a/python/ray/tests/test_webui.py
+++ b/python/ray/tests/test_webui.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import re
 import sys
 import time
diff --git a/python/ray/tune/__init__.py b/python/ray/tune/__init__.py
index 0488109c5..4c6bfd36c 100644
--- a/python/ray/tune/__init__.py
+++ b/python/ray/tune/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.tune.error import TuneError
 from ray.tune.tune import run_experiments, run
 from ray.tune.experiment import Experiment
diff --git a/python/ray/tune/analysis/__init__.py b/python/ray/tune/analysis/__init__.py
index 9d9f1725c..8d87e1e64 100644
--- a/python/ray/tune/analysis/__init__.py
+++ b/python/ray/tune/analysis/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.tune.analysis.experiment_analysis import ExperimentAnalysis, Analysis
 
 __all__ = ["ExperimentAnalysis", "Analysis"]
diff --git a/python/ray/tune/analysis/experiment_analysis.py b/python/ray/tune/analysis/experiment_analysis.py
index 794bd5d64..cc59f8436 100644
--- a/python/ray/tune/analysis/experiment_analysis.py
+++ b/python/ray/tune/analysis/experiment_analysis.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import json
 import logging
 import os
diff --git a/python/ray/tune/automl/__init__.py b/python/ray/tune/automl/__init__.py
index cab4c4de4..121b35795 100644
--- a/python/ray/tune/automl/__init__.py
+++ b/python/ray/tune/automl/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.tune.automl.genetic_searcher import GeneticSearch
 from ray.tune.automl.search_policy import GridSearch, RandomSearch
 from ray.tune.automl.search_space import SearchSpace, \
diff --git a/python/ray/tune/automl/genetic_searcher.py b/python/ray/tune/automl/genetic_searcher.py
index 64e82f501..b0f60c312 100644
--- a/python/ray/tune/automl/genetic_searcher.py
+++ b/python/ray/tune/automl/genetic_searcher.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 
diff --git a/python/ray/tune/automl/search_policy.py b/python/ray/tune/automl/search_policy.py
index a35ccb462..b636d53e4 100644
--- a/python/ray/tune/automl/search_policy.py
+++ b/python/ray/tune/automl/search_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import time
 import copy
 import logging
diff --git a/python/ray/tune/automl/search_space.py b/python/ray/tune/automl/search_space.py
index 2f7743c69..25207434a 100644
--- a/python/ray/tune/automl/search_space.py
+++ b/python/ray/tune/automl/search_space.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import random
 import logging
 import numpy as np
diff --git a/python/ray/tune/automlboard/backend/collector.py b/python/ray/tune/automlboard/backend/collector.py
index f9b1bd488..0701b90e5 100644
--- a/python/ray/tune/automlboard/backend/collector.py
+++ b/python/ray/tune/automlboard/backend/collector.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import os
 import time
diff --git a/python/ray/tune/automlboard/common/exception.py b/python/ray/tune/automlboard/common/exception.py
index c8918f416..0b913addc 100644
--- a/python/ray/tune/automlboard/common/exception.py
+++ b/python/ray/tune/automlboard/common/exception.py
@@ -1,8 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-
 class CollectorError(Exception):
     """Error raised from the collector service."""
 
diff --git a/python/ray/tune/automlboard/common/utils.py b/python/ray/tune/automlboard/common/utils.py
index 551afbfe3..c588ee264 100644
--- a/python/ray/tune/automlboard/common/utils.py
+++ b/python/ray/tune/automlboard/common/utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import json
 import os
diff --git a/python/ray/tune/automlboard/frontend/query.py b/python/ray/tune/automlboard/frontend/query.py
index 75ea0cc94..ead71a23b 100644
--- a/python/ray/tune/automlboard/frontend/query.py
+++ b/python/ray/tune/automlboard/frontend/query.py
@@ -1,8 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-
 from django.shortcuts import HttpResponse
 
 from ray.tune.automlboard.models.models import JobRecord, TrialRecord
diff --git a/python/ray/tune/automlboard/frontend/urls.py b/python/ray/tune/automlboard/frontend/urls.py
index 118fb77ce..5422f6b47 100644
--- a/python/ray/tune/automlboard/frontend/urls.py
+++ b/python/ray/tune/automlboard/frontend/urls.py
@@ -18,10 +18,6 @@ Including another URLconf
     2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
 
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from django.conf.urls import url
 from django.contrib import admin
 
diff --git a/python/ray/tune/automlboard/frontend/view.py b/python/ray/tune/automlboard/frontend/view.py
index 4101c0212..8f8c5f515 100644
--- a/python/ray/tune/automlboard/frontend/view.py
+++ b/python/ray/tune/automlboard/frontend/view.py
@@ -1,8 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-
 from django.shortcuts import render
 
 from ray.tune.automlboard.settings import AUTOMLBOARD_RELOAD_INTERVAL, \
diff --git a/python/ray/tune/automlboard/frontend/wsgi.py b/python/ray/tune/automlboard/frontend/wsgi.py
index 45806a653..3eaddd449 100644
--- a/python/ray/tune/automlboard/frontend/wsgi.py
+++ b/python/ray/tune/automlboard/frontend/wsgi.py
@@ -7,10 +7,6 @@ For more information on this file, see
 https://docs.djangoproject.com/en/1.11/howto/deployment/wsgi/
 
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from django.core.wsgi import get_wsgi_application
 
 import os
diff --git a/python/ray/tune/automlboard/manage.py b/python/ray/tune/automlboard/manage.py
index 1e4845d8e..e3c599cde 100755
--- a/python/ray/tune/automlboard/manage.py
+++ b/python/ray/tune/automlboard/manage.py
@@ -1,8 +1,4 @@
 #!/usr/bin/env python
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from django.core.management import execute_from_command_line
 import os
 import sys
diff --git a/python/ray/tune/automlboard/models/apps.py b/python/ray/tune/automlboard/models/apps.py
index d4c16ce41..471ea7e3b 100644
--- a/python/ray/tune/automlboard/models/apps.py
+++ b/python/ray/tune/automlboard/models/apps.py
@@ -1,8 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-
 from django.apps import AppConfig
 
 
diff --git a/python/ray/tune/automlboard/models/models.py b/python/ray/tune/automlboard/models/models.py
index c3770bce2..73abc76a9 100644
--- a/python/ray/tune/automlboard/models/models.py
+++ b/python/ray/tune/automlboard/models/models.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from django.db import models
 
 
diff --git a/python/ray/tune/automlboard/run.py b/python/ray/tune/automlboard/run.py
index 5304a56ef..d1dbb1ceb 100644
--- a/python/ray/tune/automlboard/run.py
+++ b/python/ray/tune/automlboard/run.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import os
 import re
diff --git a/python/ray/tune/automlboard/settings.py b/python/ray/tune/automlboard/settings.py
index 2bd940fc9..c3bc8d335 100644
--- a/python/ray/tune/automlboard/settings.py
+++ b/python/ray/tune/automlboard/settings.py
@@ -10,10 +10,6 @@ For the full list of settings and their values, see
 https://docs.djangoproject.com/en/1.11/ref/settings/
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 
 # Build paths inside the project like this:
diff --git a/python/ray/tune/checkpoint_manager.py b/python/ray/tune/checkpoint_manager.py
index 9c745653b..d4a5bcd1e 100644
--- a/python/ray/tune/checkpoint_manager.py
+++ b/python/ray/tune/checkpoint_manager.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import heapq
 import logging
 
diff --git a/python/ray/tune/cluster_info.py b/python/ray/tune/cluster_info.py
index 082870efe..c28702948 100644
--- a/python/ray/tune/cluster_info.py
+++ b/python/ray/tune/cluster_info.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import getpass
 import os
 
diff --git a/python/ray/tune/commands.py b/python/ray/tune/commands.py
index cc4248657..2ab17e609 100644
--- a/python/ray/tune/commands.py
+++ b/python/ray/tune/commands.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import click
 import logging
 import os
diff --git a/python/ray/tune/config_parser.py b/python/ray/tune/config_parser.py
index 9ba4889ff..d87e1ce28 100644
--- a/python/ray/tune/config_parser.py
+++ b/python/ray/tune/config_parser.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import json
 import os
diff --git a/python/ray/tune/durable_trainable.py b/python/ray/tune/durable_trainable.py
index 987551728..981e1bc89 100644
--- a/python/ray/tune/durable_trainable.py
+++ b/python/ray/tune/durable_trainable.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 
 from ray.tune.trainable import Trainable, TrainableUtil
diff --git a/python/ray/tune/error.py b/python/ray/tune/error.py
index 2afd47a92..fa376c394 100644
--- a/python/ray/tune/error.py
+++ b/python/ray/tune/error.py
@@ -1,8 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-
 class TuneError(Exception):
     """General error class raised by ray.tune."""
     pass
diff --git a/python/ray/tune/examples/async_hyperband_example.py b/python/ray/tune/examples/async_hyperband_example.py
index 5a3b08185..ebf30f66b 100644
--- a/python/ray/tune/examples/async_hyperband_example.py
+++ b/python/ray/tune/examples/async_hyperband_example.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import json
 import os
diff --git a/python/ray/tune/examples/ax_example.py b/python/ray/tune/examples/ax_example.py
index 54081c750..505c4f1af 100644
--- a/python/ray/tune/examples/ax_example.py
+++ b/python/ray/tune/examples/ax_example.py
@@ -2,10 +2,6 @@
 
 It also checks that it is usable with a separate scheduler.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 import ray
diff --git a/python/ray/tune/examples/bayesopt_example.py b/python/ray/tune/examples/bayesopt_example.py
index d08d79056..4317d3340 100644
--- a/python/ray/tune/examples/bayesopt_example.py
+++ b/python/ray/tune/examples/bayesopt_example.py
@@ -2,10 +2,6 @@
 
 It also checks that it is usable with a separate scheduler.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.tune import run
 from ray.tune.schedulers import AsyncHyperBandScheduler
diff --git a/python/ray/tune/examples/bohb_example.py b/python/ray/tune/examples/bohb_example.py
index 802390fbe..3fc1cda8c 100644
--- a/python/ray/tune/examples/bohb_example.py
+++ b/python/ray/tune/examples/bohb_example.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import json
 import os
diff --git a/python/ray/tune/examples/genetic_example.py b/python/ray/tune/examples/genetic_example.py
index fdcf54881..3b16de0d4 100644
--- a/python/ray/tune/examples/genetic_example.py
+++ b/python/ray/tune/examples/genetic_example.py
@@ -2,10 +2,6 @@
 
 It also checks that it is usable with a separate scheduler.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.tune import run
 from ray.tune.schedulers import AsyncHyperBandScheduler
diff --git a/python/ray/tune/examples/hyperband_example.py b/python/ray/tune/examples/hyperband_example.py
index 6db2ec2fd..e1ed629e7 100755
--- a/python/ray/tune/examples/hyperband_example.py
+++ b/python/ray/tune/examples/hyperband_example.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import json
 import os
diff --git a/python/ray/tune/examples/hyperopt_example.py b/python/ray/tune/examples/hyperopt_example.py
index 029ceb2bd..dc2793563 100644
--- a/python/ray/tune/examples/hyperopt_example.py
+++ b/python/ray/tune/examples/hyperopt_example.py
@@ -2,10 +2,6 @@
 
 It also checks that it is usable with a separate scheduler.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.tune import run
 from ray.tune.schedulers import AsyncHyperBandScheduler
diff --git a/python/ray/tune/examples/lightgbm_example.py b/python/ray/tune/examples/lightgbm_example.py
index 7a45bb3ce..33b670dc0 100644
--- a/python/ray/tune/examples/lightgbm_example.py
+++ b/python/ray/tune/examples/lightgbm_example.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import lightgbm as lgb
 import numpy as np
 import sklearn.datasets
diff --git a/python/ray/tune/examples/logging_example.py b/python/ray/tune/examples/logging_example.py
index 3bacd0975..9643034e7 100755
--- a/python/ray/tune/examples/logging_example.py
+++ b/python/ray/tune/examples/logging_example.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import json
 import os
diff --git a/python/ray/tune/examples/mlflow_example.py b/python/ray/tune/examples/mlflow_example.py
index 5eb77fd08..b285355cb 100644
--- a/python/ray/tune/examples/mlflow_example.py
+++ b/python/ray/tune/examples/mlflow_example.py
@@ -6,10 +6,6 @@ no artifact support; to save artifacts with Tune and MLFlow, you will need to
 start a MLFlow run inside the Trainable function/class.
 
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import mlflow
 from mlflow.tracking import MlflowClient
 import time
diff --git a/python/ray/tune/examples/mnist_pytorch.py b/python/ray/tune/examples/mnist_pytorch.py
index 99cc38b27..b6858cea2 100644
--- a/python/ray/tune/examples/mnist_pytorch.py
+++ b/python/ray/tune/examples/mnist_pytorch.py
@@ -1,9 +1,5 @@
 # Original Code here:
 # https://github.com/pytorch/examples/blob/master/mnist/main.py
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import numpy as np
 import argparse
diff --git a/python/ray/tune/examples/nevergrad_example.py b/python/ray/tune/examples/nevergrad_example.py
index b70228acd..7a0e53aba 100644
--- a/python/ray/tune/examples/nevergrad_example.py
+++ b/python/ray/tune/examples/nevergrad_example.py
@@ -2,10 +2,6 @@
 
 It also checks that it is usable with a separate scheduler.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.tune import run
 from ray.tune.schedulers import AsyncHyperBandScheduler
diff --git a/python/ray/tune/examples/pbt_convnet_example.py b/python/ray/tune/examples/pbt_convnet_example.py
index 4fb1db7c4..803c816c5 100644
--- a/python/ray/tune/examples/pbt_convnet_example.py
+++ b/python/ray/tune/examples/pbt_convnet_example.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 # __tutorial_imports_begin__
 import argparse
 import os
diff --git a/python/ray/tune/examples/pbt_dcgan_mnist/pbt_dcgan_mnist.py b/python/ray/tune/examples/pbt_dcgan_mnist/pbt_dcgan_mnist.py
index 6aa12d2db..2515b1eed 100644
--- a/python/ray/tune/examples/pbt_dcgan_mnist/pbt_dcgan_mnist.py
+++ b/python/ray/tune/examples/pbt_dcgan_mnist/pbt_dcgan_mnist.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray import tune
 from ray.tune.schedulers import PopulationBasedTraining
diff --git a/python/ray/tune/examples/pbt_example.py b/python/ray/tune/examples/pbt_example.py
index c3acecdab..13ed2b09f 100755
--- a/python/ray/tune/examples/pbt_example.py
+++ b/python/ray/tune/examples/pbt_example.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import argparse
 import random
diff --git a/python/ray/tune/examples/pbt_ppo_example.py b/python/ray/tune/examples/pbt_ppo_example.py
index 26b7c80a7..1478541f6 100755
--- a/python/ray/tune/examples/pbt_ppo_example.py
+++ b/python/ray/tune/examples/pbt_ppo_example.py
@@ -9,10 +9,6 @@ Note that Tune in general does not need 8 GPUs, and this is just a more
 computationally demainding example.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import random
 
 import ray
diff --git a/python/ray/tune/examples/sigopt_example.py b/python/ray/tune/examples/sigopt_example.py
index 84b753609..b82aa3eeb 100644
--- a/python/ray/tune/examples/sigopt_example.py
+++ b/python/ray/tune/examples/sigopt_example.py
@@ -2,10 +2,6 @@
 
 It also checks that it is usable with a separate scheduler.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.tune import run
 from ray.tune.schedulers import AsyncHyperBandScheduler
diff --git a/python/ray/tune/examples/skopt_example.py b/python/ray/tune/examples/skopt_example.py
index ac6ed8274..a62932cf7 100644
--- a/python/ray/tune/examples/skopt_example.py
+++ b/python/ray/tune/examples/skopt_example.py
@@ -2,10 +2,6 @@
 
 It also checks that it is usable with a separate scheduler.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.tune import run
 from ray.tune.schedulers import AsyncHyperBandScheduler
diff --git a/python/ray/tune/examples/tf_mnist_example.py b/python/ray/tune/examples/tf_mnist_example.py
index 41147d4e5..66749ec2d 100644
--- a/python/ray/tune/examples/tf_mnist_example.py
+++ b/python/ray/tune/examples/tf_mnist_example.py
@@ -9,11 +9,6 @@
 # this is to `import tensorflow` inside the Tune Trainable.
 #
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-
 import argparse
 from tensorflow.keras.layers import Dense, Flatten, Conv2D
 from tensorflow.keras import Model
diff --git a/python/ray/tune/examples/track_example.py b/python/ray/tune/examples/track_example.py
index 751f0ed44..9b9604562 100644
--- a/python/ray/tune/examples/track_example.py
+++ b/python/ray/tune/examples/track_example.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import keras
 from keras.datasets import mnist
diff --git a/python/ray/tune/examples/tune_mnist_keras.py b/python/ray/tune/examples/tune_mnist_keras.py
index b3a13884a..98901f53d 100644
--- a/python/ray/tune/examples/tune_mnist_keras.py
+++ b/python/ray/tune/examples/tune_mnist_keras.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import numpy as np
 from tensorflow.keras.datasets import mnist
diff --git a/python/ray/tune/examples/utils.py b/python/ray/tune/examples/utils.py
index bee27a889..1eb6d98af 100644
--- a/python/ray/tune/examples/utils.py
+++ b/python/ray/tune/examples/utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import tensorflow as tf
 import keras
 from keras.datasets import mnist
diff --git a/python/ray/tune/examples/xgboost_example.py b/python/ray/tune/examples/xgboost_example.py
index ca295de07..0bac5a1c2 100644
--- a/python/ray/tune/examples/xgboost_example.py
+++ b/python/ray/tune/examples/xgboost_example.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import xgboost as xgb
 import numpy as np
 import sklearn.datasets
diff --git a/python/ray/tune/experiment.py b/python/ray/tune/experiment.py
index 9d65735fa..0bd5a7fe4 100644
--- a/python/ray/tune/experiment.py
+++ b/python/ray/tune/experiment.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import inspect
 import logging
diff --git a/python/ray/tune/function_runner.py b/python/ray/tune/function_runner.py
index ddbb85b95..e46db3cc8 100644
--- a/python/ray/tune/function_runner.py
+++ b/python/ray/tune/function_runner.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import time
 import inspect
diff --git a/python/ray/tune/integration/keras.py b/python/ray/tune/integration/keras.py
index 0df8cf2d3..cab37ab39 100644
--- a/python/ray/tune/integration/keras.py
+++ b/python/ray/tune/integration/keras.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from tensorflow import keras
 from ray.tune import track
 
diff --git a/python/ray/tune/logger.py b/python/ray/tune/logger.py
index c5ff1eed1..c41719792 100644
--- a/python/ray/tune/logger.py
+++ b/python/ray/tune/logger.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import csv
 import json
 import logging
diff --git a/python/ray/tune/ray_trial_executor.py b/python/ray/tune/ray_trial_executor.py
index f82e99145..ecf6d0f30 100644
--- a/python/ray/tune/ray_trial_executor.py
+++ b/python/ray/tune/ray_trial_executor.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import os
 import random
diff --git a/python/ray/tune/registry.py b/python/ray/tune/registry.py
index 9b5b178c9..11b8ac4c3 100644
--- a/python/ray/tune/registry.py
+++ b/python/ray/tune/registry.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 from types import FunctionType
 
diff --git a/python/ray/tune/resources.py b/python/ray/tune/resources.py
index 17ef70bff..8f86ad707 100644
--- a/python/ray/tune/resources.py
+++ b/python/ray/tune/resources.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import namedtuple
 import logging
 import json
diff --git a/python/ray/tune/result.py b/python/ray/tune/result.py
index aec191535..2861efc57 100644
--- a/python/ray/tune/result.py
+++ b/python/ray/tune/result.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 
 # yapf: disable
diff --git a/python/ray/tune/sample.py b/python/ray/tune/sample.py
index 5cfb11c7f..bb8c9cb55 100644
--- a/python/ray/tune/sample.py
+++ b/python/ray/tune/sample.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 
diff --git a/python/ray/tune/schedulers/__init__.py b/python/ray/tune/schedulers/__init__.py
index 3731724c9..fdbe016c3 100644
--- a/python/ray/tune/schedulers/__init__.py
+++ b/python/ray/tune/schedulers/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.tune.schedulers.trial_scheduler import TrialScheduler, FIFOScheduler
 from ray.tune.schedulers.hyperband import HyperBandScheduler
 from ray.tune.schedulers.hb_bohb import HyperBandForBOHB
diff --git a/python/ray/tune/schedulers/async_hyperband.py b/python/ray/tune/schedulers/async_hyperband.py
index 89ce09669..80c52c8c0 100644
--- a/python/ray/tune/schedulers/async_hyperband.py
+++ b/python/ray/tune/schedulers/async_hyperband.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 
diff --git a/python/ray/tune/schedulers/hb_bohb.py b/python/ray/tune/schedulers/hb_bohb.py
index 428ffa6f7..b63504c05 100644
--- a/python/ray/tune/schedulers/hb_bohb.py
+++ b/python/ray/tune/schedulers/hb_bohb.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from ray.tune.schedulers.trial_scheduler import TrialScheduler
diff --git a/python/ray/tune/schedulers/hyperband.py b/python/ray/tune/schedulers/hyperband.py
index 66188028f..c55c1c5ba 100644
--- a/python/ray/tune/schedulers/hyperband.py
+++ b/python/ray/tune/schedulers/hyperband.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import numpy as np
 import logging
diff --git a/python/ray/tune/schedulers/median_stopping_rule.py b/python/ray/tune/schedulers/median_stopping_rule.py
index 99b4c4d80..2389f166e 100644
--- a/python/ray/tune/schedulers/median_stopping_rule.py
+++ b/python/ray/tune/schedulers/median_stopping_rule.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import logging
 import numpy as np
diff --git a/python/ray/tune/schedulers/pbt.py b/python/ray/tune/schedulers/pbt.py
index fa0f8c416..e864fba49 100644
--- a/python/ray/tune/schedulers/pbt.py
+++ b/python/ray/tune/schedulers/pbt.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import itertools
 import logging
diff --git a/python/ray/tune/schedulers/trial_scheduler.py b/python/ray/tune/schedulers/trial_scheduler.py
index 2e85ac90f..6fe7284cf 100644
--- a/python/ray/tune/schedulers/trial_scheduler.py
+++ b/python/ray/tune/schedulers/trial_scheduler.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.tune.trial import Trial
 
 
diff --git a/python/ray/tune/scripts.py b/python/ray/tune/scripts.py
index 344087c22..4310cf611 100644
--- a/python/ray/tune/scripts.py
+++ b/python/ray/tune/scripts.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import click
 import ray.tune.commands as commands
 
diff --git a/python/ray/tune/suggest/ax.py b/python/ray/tune/suggest/ax.py
index d917879aa..92071995d 100644
--- a/python/ray/tune/suggest/ax.py
+++ b/python/ray/tune/suggest/ax.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 try:
     import ax
 except ImportError:
diff --git a/python/ray/tune/suggest/basic_variant.py b/python/ray/tune/suggest/basic_variant.py
index 84096efbe..2cf04353b 100644
--- a/python/ray/tune/suggest/basic_variant.py
+++ b/python/ray/tune/suggest/basic_variant.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import itertools
 import random
 
diff --git a/python/ray/tune/suggest/bayesopt.py b/python/ray/tune/suggest/bayesopt.py
index 0bb35d707..be39f9a45 100644
--- a/python/ray/tune/suggest/bayesopt.py
+++ b/python/ray/tune/suggest/bayesopt.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import logging
 import pickle
diff --git a/python/ray/tune/suggest/bohb.py b/python/ray/tune/suggest/bohb.py
index 3fe5d5877..9972d920a 100644
--- a/python/ray/tune/suggest/bohb.py
+++ b/python/ray/tune/suggest/bohb.py
@@ -1,9 +1,5 @@
 """BOHB (Bayesian Optimization with HyperBand)"""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import logging
 
diff --git a/python/ray/tune/suggest/hyperopt.py b/python/ray/tune/suggest/hyperopt.py
index bb6614fd3..bd9bee72b 100644
--- a/python/ray/tune/suggest/hyperopt.py
+++ b/python/ray/tune/suggest/hyperopt.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import copy
 import logging
diff --git a/python/ray/tune/suggest/nevergrad.py b/python/ray/tune/suggest/nevergrad.py
index 1685774b9..be9a36447 100644
--- a/python/ray/tune/suggest/nevergrad.py
+++ b/python/ray/tune/suggest/nevergrad.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import pickle
 try:
diff --git a/python/ray/tune/suggest/search.py b/python/ray/tune/suggest/search.py
index f18f7e3ac..e80767b40 100644
--- a/python/ray/tune/suggest/search.py
+++ b/python/ray/tune/suggest/search.py
@@ -1,8 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-
 class SearchAlgorithm:
     """Interface of an event handler API for hyperparameter search.
 
diff --git a/python/ray/tune/suggest/sigopt.py b/python/ray/tune/suggest/sigopt.py
index b88ab0b6b..0f825e78e 100644
--- a/python/ray/tune/suggest/sigopt.py
+++ b/python/ray/tune/suggest/sigopt.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import os
 import logging
diff --git a/python/ray/tune/suggest/skopt.py b/python/ray/tune/suggest/skopt.py
index cba3e664c..e0d9b8577 100644
--- a/python/ray/tune/suggest/skopt.py
+++ b/python/ray/tune/suggest/skopt.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import pickle
 try:
diff --git a/python/ray/tune/suggest/suggestion.py b/python/ray/tune/suggest/suggestion.py
index 554322266..51f621970 100644
--- a/python/ray/tune/suggest/suggestion.py
+++ b/python/ray/tune/suggest/suggestion.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import itertools
 import copy
 
diff --git a/python/ray/tune/suggest/variant_generator.py b/python/ray/tune/suggest/variant_generator.py
index ead2b023e..6e7092536 100644
--- a/python/ray/tune/suggest/variant_generator.py
+++ b/python/ray/tune/suggest/variant_generator.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import logging
 import numpy
diff --git a/python/ray/tune/sync_client.py b/python/ray/tune/sync_client.py
index 13a88f1c7..87f5f4e06 100644
--- a/python/ray/tune/sync_client.py
+++ b/python/ray/tune/sync_client.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import distutils
 import distutils.spawn
 import logging
diff --git a/python/ray/tune/syncer.py b/python/ray/tune/syncer.py
index ff7e305b0..25f88023e 100644
--- a/python/ray/tune/syncer.py
+++ b/python/ray/tune/syncer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import distutils
 import logging
 import os
diff --git a/python/ray/tune/tests/test_actor_reuse.py b/python/ray/tune/tests/test_actor_reuse.py
index c3a4b2442..e1d8df0d3 100644
--- a/python/ray/tune/tests/test_actor_reuse.py
+++ b/python/ray/tune/tests/test_actor_reuse.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 
 import ray
diff --git a/python/ray/tune/tests/test_api.py b/python/ray/tune/tests/test_api.py
index 16304fd3b..22d51e614 100644
--- a/python/ray/tune/tests/test_api.py
+++ b/python/ray/tune/tests/test_api.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import shutil
 
 import copy
diff --git a/python/ray/tune/tests/test_automl_searcher.py b/python/ray/tune/tests/test_automl_searcher.py
index 05cd4b574..22e98896e 100644
--- a/python/ray/tune/tests/test_automl_searcher.py
+++ b/python/ray/tune/tests/test_automl_searcher.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import random
 import unittest
 
diff --git a/python/ray/tune/tests/test_checkpoint_manager.py b/python/ray/tune/tests/test_checkpoint_manager.py
index 93ea38d37..24451a1c2 100644
--- a/python/ray/tune/tests/test_checkpoint_manager.py
+++ b/python/ray/tune/tests/test_checkpoint_manager.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import random
 import sys
 import unittest
diff --git a/python/ray/tune/tests/test_cluster.py b/python/ray/tune/tests/test_cluster.py
index cd78d964b..e54789ed9 100644
--- a/python/ray/tune/tests/test_cluster.py
+++ b/python/ray/tune/tests/test_cluster.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import inspect
 import json
 import time
diff --git a/python/ray/tune/tests/test_commands.py b/python/ray/tune/tests/test_commands.py
index 6ce21dd77..4a8d8e984 100644
--- a/python/ray/tune/tests/test_commands.py
+++ b/python/ray/tune/tests/test_commands.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import click
 import os
 import pytest
diff --git a/python/ray/tune/tests/test_dependency.py b/python/ray/tune/tests/test_dependency.py
index 6aa9d066c..ce5d7a28b 100644
--- a/python/ray/tune/tests/test_dependency.py
+++ b/python/ray/tune/tests/test_dependency.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import sys
 
 import ray
diff --git a/python/ray/tune/tests/test_experiment.py b/python/ray/tune/tests/test_experiment.py
index 035ce8391..de5fbc5ca 100644
--- a/python/ray/tune/tests/test_experiment.py
+++ b/python/ray/tune/tests/test_experiment.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 
 import ray
diff --git a/python/ray/tune/tests/test_experiment_analysis.py b/python/ray/tune/tests/test_experiment_analysis.py
index a6df95b72..813fcaa11 100644
--- a/python/ray/tune/tests/test_experiment_analysis.py
+++ b/python/ray/tune/tests/test_experiment_analysis.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 import shutil
 import tempfile
diff --git a/python/ray/tune/tests/test_experiment_analysis_mem.py b/python/ray/tune/tests/test_experiment_analysis_mem.py
index fa5330097..e0b660543 100644
--- a/python/ray/tune/tests/test_experiment_analysis_mem.py
+++ b/python/ray/tune/tests/test_experiment_analysis_mem.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 import shutil
 import tempfile
diff --git a/python/ray/tune/tests/test_logger.py b/python/ray/tune/tests/test_logger.py
index 30a7e491e..ed9a0b3a7 100644
--- a/python/ray/tune/tests/test_logger.py
+++ b/python/ray/tune/tests/test_logger.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import namedtuple
 import unittest
 import tempfile
diff --git a/python/ray/tune/tests/test_progress_reporter.py b/python/ray/tune/tests/test_progress_reporter.py
index 210cf0d37..fd3031599 100644
--- a/python/ray/tune/tests/test_progress_reporter.py
+++ b/python/ray/tune/tests/test_progress_reporter.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import time
 import unittest
diff --git a/python/ray/tune/tests/test_ray_trial_executor.py b/python/ray/tune/tests/test_ray_trial_executor.py
index abdb49a9a..70bc7c913 100644
--- a/python/ray/tune/tests/test_ray_trial_executor.py
+++ b/python/ray/tune/tests/test_ray_trial_executor.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import json
 import unittest
 
diff --git a/python/ray/tune/tests/test_run_experiment.py b/python/ray/tune/tests/test_run_experiment.py
index 9ce25d39c..98b7b1291 100644
--- a/python/ray/tune/tests/test_run_experiment.py
+++ b/python/ray/tune/tests/test_run_experiment.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import unittest
 
diff --git a/python/ray/tune/tests/test_sync.py b/python/ray/tune/tests/test_sync.py
index 25609a3d6..c4b502460 100644
--- a/python/ray/tune/tests/test_sync.py
+++ b/python/ray/tune/tests/test_sync.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import glob
 import os
 import shutil
diff --git a/python/ray/tune/tests/test_track.py b/python/ray/tune/tests/test_track.py
index 6bbe4ee1c..fbf734c41 100644
--- a/python/ray/tune/tests/test_track.py
+++ b/python/ray/tune/tests/test_track.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import pandas as pd
 import unittest
diff --git a/python/ray/tune/tests/test_trainable_util.py b/python/ray/tune/tests/test_trainable_util.py
index d7a0f6689..2664b4554 100644
--- a/python/ray/tune/tests/test_trainable_util.py
+++ b/python/ray/tune/tests/test_trainable_util.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import pickle
 import shutil
diff --git a/python/ray/tune/tests/test_trial_runner.py b/python/ray/tune/tests/test_trial_runner.py
index 6099a864f..ea797a28b 100644
--- a/python/ray/tune/tests/test_trial_runner.py
+++ b/python/ray/tune/tests/test_trial_runner.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import sys
 import unittest
 
diff --git a/python/ray/tune/tests/test_trial_runner_2.py b/python/ray/tune/tests/test_trial_runner_2.py
index 3b76d9810..17fcf8093 100644
--- a/python/ray/tune/tests/test_trial_runner_2.py
+++ b/python/ray/tune/tests/test_trial_runner_2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import sys
 import unittest
diff --git a/python/ray/tune/tests/test_trial_runner_3.py b/python/ray/tune/tests/test_trial_runner_3.py
index 82fd32611..e46706251 100644
--- a/python/ray/tune/tests/test_trial_runner_3.py
+++ b/python/ray/tune/tests/test_trial_runner_3.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import shutil
 import sys
diff --git a/python/ray/tune/tests/test_trial_scheduler.py b/python/ray/tune/tests/test_trial_scheduler.py
index 9c73344d9..d187f95c8 100644
--- a/python/ray/tune/tests/test_trial_scheduler.py
+++ b/python/ray/tune/tests/test_trial_scheduler.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import json
 import random
diff --git a/python/ray/tune/tests/test_tune_restore.py b/python/ray/tune/tests/test_tune_restore.py
index 3b7c7aacb..726a82e98 100644
--- a/python/ray/tune/tests/test_tune_restore.py
+++ b/python/ray/tune/tests/test_tune_restore.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import shutil
 import tempfile
diff --git a/python/ray/tune/tests/test_tune_save_restore.py b/python/ray/tune/tests/test_tune_save_restore.py
index 358436bed..9a5e0f476 100644
--- a/python/ray/tune/tests/test_tune_save_restore.py
+++ b/python/ray/tune/tests/test_tune_save_restore.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import pickle
 import shutil
diff --git a/python/ray/tune/tests/test_tune_server.py b/python/ray/tune/tests/test_tune_server.py
index 9f9d6e91e..af5556a87 100644
--- a/python/ray/tune/tests/test_tune_server.py
+++ b/python/ray/tune/tests/test_tune_server.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 import socket
 import subprocess
diff --git a/python/ray/tune/tests/test_var.py b/python/ray/tune/tests/test_var.py
index 8a0fba749..3b9695a00 100644
--- a/python/ray/tune/tests/test_var.py
+++ b/python/ray/tune/tests/test_var.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import numpy as np
 import unittest
diff --git a/python/ray/tune/track/__init__.py b/python/ray/tune/track/__init__.py
index a35511e89..ceef69181 100644
--- a/python/ray/tune/track/__init__.py
+++ b/python/ray/tune/track/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from ray.tune.track.session import TrackSession
diff --git a/python/ray/tune/track/session.py b/python/ray/tune/track/session.py
index af9600729..ab402559d 100644
--- a/python/ray/tune/track/session.py
+++ b/python/ray/tune/track/session.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 from datetime import datetime
 
diff --git a/python/ray/tune/trainable.py b/python/ray/tune/trainable.py
index a87f74191..b0aeab944 100644
--- a/python/ray/tune/trainable.py
+++ b/python/ray/tune/trainable.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from datetime import datetime
 
 import copy
diff --git a/python/ray/tune/trial.py b/python/ray/tune/trial.py
index 93f9a3d78..f3d0da9fa 100644
--- a/python/ray/tune/trial.py
+++ b/python/ray/tune/trial.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray.cloudpickle as cloudpickle
 import copy
 from datetime import datetime
diff --git a/python/ray/tune/trial_executor.py b/python/ray/tune/trial_executor.py
index 26c023788..83696fac7 100644
--- a/python/ray/tune/trial_executor.py
+++ b/python/ray/tune/trial_executor.py
@@ -1,8 +1,4 @@
 # coding: utf-8
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from ray.tune.trial import Trial, Checkpoint
diff --git a/python/ray/tune/trial_runner.py b/python/ray/tune/trial_runner.py
index 12fa3cd36..2b171e250 100644
--- a/python/ray/tune/trial_runner.py
+++ b/python/ray/tune/trial_runner.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import click
 from datetime import datetime
 import json
diff --git a/python/ray/tune/tune.py b/python/ray/tune/tune.py
index 844a212f8..89a5451cd 100644
--- a/python/ray/tune/tune.py
+++ b/python/ray/tune/tune.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import time
 import six
diff --git a/python/ray/tune/utils/mock.py b/python/ray/tune/utils/mock.py
index 7f3be4c44..857de431a 100644
--- a/python/ray/tune/utils/mock.py
+++ b/python/ray/tune/utils/mock.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 
 from ray.rllib.agents.mock import _MockTrainer
diff --git a/python/ray/tune/utils/util.py b/python/ray/tune/utils/util.py
index 0a9dec3f6..d68646edb 100644
--- a/python/ray/tune/utils/util.py
+++ b/python/ray/tune/utils/util.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import logging
 import threading
diff --git a/python/ray/tune/utils/visual_utils.py b/python/ray/tune/utils/visual_utils.py
index 09188f1a2..7e622799a 100644
--- a/python/ray/tune/utils/visual_utils.py
+++ b/python/ray/tune/utils/visual_utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import pandas as pd
 from pandas.api.types import is_string_dtype, is_numeric_dtype
 import logging
diff --git a/python/ray/tune/web_server.py b/python/ray/tune/web_server.py
index 9b9da1946..6802fe0c3 100644
--- a/python/ray/tune/web_server.py
+++ b/python/ray/tune/web_server.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import json
 import logging
 import threading
diff --git a/python/ray/utils.py b/python/ray/utils.py
index b467513b2..4be0af6f8 100644
--- a/python/ray/utils.py
+++ b/python/ray/utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import binascii
 import errno
 import hashlib
diff --git a/python/ray/worker.py b/python/ray/worker.py
index 1ff4677b7..83999ab8b 100644
--- a/python/ray/worker.py
+++ b/python/ray/worker.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from contextlib import contextmanager
 import colorama
 import atexit
diff --git a/python/ray/workers/default_worker.py b/python/ray/workers/default_worker.py
index 93f5f22b0..b4719285e 100644
--- a/python/ray/workers/default_worker.py
+++ b/python/ray/workers/default_worker.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import json
 
diff --git a/python/setup.py b/python/setup.py
index e9925f9f5..f15ccf16d 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import glob
 from itertools import chain
 import os
diff --git a/rllib/__init__.py b/rllib/__init__.py
index de15d530a..5d6c9b90c 100644
--- a/rllib/__init__.py
+++ b/rllib/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 # Note: do not introduce unnecessary library dependencies here, e.g. gym.
diff --git a/rllib/agents/a3c/a2c.py b/rllib/agents/a3c/a2c.py
index 0a1282f08..f8bb4c372 100644
--- a/rllib/agents/a3c/a2c.py
+++ b/rllib/agents/a3c/a2c.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.a3c.a3c import DEFAULT_CONFIG as A3C_CONFIG, \
     validate_config, get_policy_class
 from ray.rllib.optimizers import SyncSamplesOptimizer, MicrobatchOptimizer
diff --git a/rllib/agents/a3c/a3c.py b/rllib/agents/a3c/a3c.py
index 9809ef464..40f93ce99 100644
--- a/rllib/agents/a3c/a3c.py
+++ b/rllib/agents/a3c/a3c.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.a3c.a3c_tf_policy import A3CTFPolicy
 from ray.rllib.agents.trainer import with_common_config
 from ray.rllib.agents.trainer_template import build_trainer
diff --git a/rllib/agents/a3c/a3c_tf_policy.py b/rllib/agents/a3c/a3c_tf_policy.py
index 6aed17c0a..ca27836ce 100644
--- a/rllib/agents/a3c/a3c_tf_policy.py
+++ b/rllib/agents/a3c/a3c_tf_policy.py
@@ -1,9 +1,5 @@
 """Note: Keep in sync with changes to VTraceTFPolicy."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.rllib.policy.sample_batch import SampleBatch
 from ray.rllib.utils.explained_variance import explained_variance
diff --git a/rllib/agents/a3c/a3c_torch_policy.py b/rllib/agents/a3c/a3c_torch_policy.py
index e69b13a14..969781492 100644
--- a/rllib/agents/a3c/a3c_torch_policy.py
+++ b/rllib/agents/a3c/a3c_torch_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.rllib.evaluation.postprocessing import compute_advantages, \
     Postprocessing
diff --git a/rllib/agents/agent.py b/rllib/agents/agent.py
index 17da952dd..a841e95b6 100644
--- a/rllib/agents/agent.py
+++ b/rllib/agents/agent.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.trainer import Trainer
 from ray.rllib.utils import renamed_agent
 
diff --git a/rllib/agents/ars/ars.py b/rllib/agents/ars/ars.py
index f461e24c5..29b76fc93 100644
--- a/rllib/agents/ars/ars.py
+++ b/rllib/agents/ars/ars.py
@@ -2,10 +2,6 @@
 # https://github.com/openai/evolution-strategies-starter and from
 # https://github.com/modestyachts/ARS
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import namedtuple
 import logging
 import numpy as np
diff --git a/rllib/agents/ars/optimizers.py b/rllib/agents/ars/optimizers.py
index 5297c1ad7..3c36609b2 100644
--- a/rllib/agents/ars/optimizers.py
+++ b/rllib/agents/ars/optimizers.py
@@ -1,10 +1,6 @@
 # Code in this file is copied and adapted from
 # https://github.com/openai/evolution-strategies-starter.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 
diff --git a/rllib/agents/ars/policies.py b/rllib/agents/ars/policies.py
index 1ce059410..fe28740e6 100644
--- a/rllib/agents/ars/policies.py
+++ b/rllib/agents/ars/policies.py
@@ -1,10 +1,6 @@
 # Code in this file is copied and adapted from
 # https://github.com/openai/evolution-strategies-starter.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import numpy as np
 
diff --git a/rllib/agents/ars/utils.py b/rllib/agents/ars/utils.py
index 518fd3d00..2c18d07e4 100644
--- a/rllib/agents/ars/utils.py
+++ b/rllib/agents/ars/utils.py
@@ -1,10 +1,6 @@
 # Code in this file is copied and adapted from
 # https://github.com/openai/evolution-strategies-starter.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 from ray.rllib.utils import try_import_tf
 
diff --git a/rllib/agents/ddpg/__init__.py b/rllib/agents/ddpg/__init__.py
index 3d681b835..018c75d6e 100644
--- a/rllib/agents/ddpg/__init__.py
+++ b/rllib/agents/ddpg/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.ddpg.apex import ApexDDPGTrainer
 from ray.rllib.agents.ddpg.ddpg import DDPGTrainer, DEFAULT_CONFIG
 from ray.rllib.agents.ddpg.td3 import TD3Trainer
diff --git a/rllib/agents/ddpg/apex.py b/rllib/agents/ddpg/apex.py
index e0731e87a..248bab288 100644
--- a/rllib/agents/ddpg/apex.py
+++ b/rllib/agents/ddpg/apex.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.dqn.apex import APEX_TRAINER_PROPERTIES
 from ray.rllib.agents.ddpg.ddpg import DDPGTrainer, \
     DEFAULT_CONFIG as DDPG_CONFIG
diff --git a/rllib/agents/ddpg/ddpg.py b/rllib/agents/ddpg/ddpg.py
index a6b42f1ca..d4ab24e53 100644
--- a/rllib/agents/ddpg/ddpg.py
+++ b/rllib/agents/ddpg/ddpg.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.trainer import with_common_config
 from ray.rllib.agents.dqn.dqn import GenericOffPolicyTrainer, \
     update_worker_explorations
diff --git a/rllib/agents/ddpg/ddpg_policy.py b/rllib/agents/ddpg/ddpg_policy.py
index caf2754ef..707e1d57e 100644
--- a/rllib/agents/ddpg/ddpg_policy.py
+++ b/rllib/agents/ddpg/ddpg_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from gym.spaces import Box
 import numpy as np
 
diff --git a/rllib/agents/ddpg/noop_model.py b/rllib/agents/ddpg/noop_model.py
index c953089c6..f2ee14ace 100644
--- a/rllib/agents/ddpg/noop_model.py
+++ b/rllib/agents/ddpg/noop_model.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.tf.tf_modelv2 import TFModelV2
 from ray.rllib.utils.annotations import override
 from ray.rllib.utils import try_import_tf
diff --git a/rllib/agents/ddpg/td3.py b/rllib/agents/ddpg/td3.py
index ad3675294..11e2cea90 100644
--- a/rllib/agents/ddpg/td3.py
+++ b/rllib/agents/ddpg/td3.py
@@ -4,10 +4,6 @@ By default, this uses a near-identical configuration to that reported in the
 TD3 paper.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.ddpg.ddpg import DDPGTrainer, \
     DEFAULT_CONFIG as DDPG_CONFIG
 from ray.rllib.utils import merge_dicts
diff --git a/rllib/agents/dqn/__init__.py b/rllib/agents/dqn/__init__.py
index d23ea0393..2eb78cc9a 100644
--- a/rllib/agents/dqn/__init__.py
+++ b/rllib/agents/dqn/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.dqn.apex import ApexTrainer
 from ray.rllib.agents.dqn.dqn import DQNTrainer, SimpleQTrainer, DEFAULT_CONFIG
 from ray.rllib.utils import renamed_agent
diff --git a/rllib/agents/dqn/apex.py b/rllib/agents/dqn/apex.py
index ab89256a6..4aae2657c 100644
--- a/rllib/agents/dqn/apex.py
+++ b/rllib/agents/dqn/apex.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.dqn.dqn import DQNTrainer, DEFAULT_CONFIG as DQN_CONFIG
 from ray.rllib.optimizers import AsyncReplayOptimizer
 from ray.rllib.utils import merge_dicts
diff --git a/rllib/agents/dqn/distributional_q_model.py b/rllib/agents/dqn/distributional_q_model.py
index 4e9e4143a..765575962 100644
--- a/rllib/agents/dqn/distributional_q_model.py
+++ b/rllib/agents/dqn/distributional_q_model.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.models.tf.tf_modelv2 import TFModelV2
diff --git a/rllib/agents/dqn/dqn.py b/rllib/agents/dqn/dqn.py
index ad1bcff99..ae947ffaf 100644
--- a/rllib/agents/dqn/dqn.py
+++ b/rllib/agents/dqn/dqn.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from ray.rllib.agents.trainer import with_common_config
diff --git a/rllib/agents/dqn/dqn_policy.py b/rllib/agents/dqn/dqn_policy.py
index 044eb9cd2..34af3839f 100644
--- a/rllib/agents/dqn/dqn_policy.py
+++ b/rllib/agents/dqn/dqn_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from gym.spaces import Discrete
 import numpy as np
 from scipy.stats import entropy
diff --git a/rllib/agents/dqn/simple_q_model.py b/rllib/agents/dqn/simple_q_model.py
index 257097799..38febe052 100644
--- a/rllib/agents/dqn/simple_q_model.py
+++ b/rllib/agents/dqn/simple_q_model.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.tf.tf_modelv2 import TFModelV2
 from ray.rllib.utils import try_import_tf
 
diff --git a/rllib/agents/dqn/simple_q_policy.py b/rllib/agents/dqn/simple_q_policy.py
index ee8dfe24c..b60c8e95e 100644
--- a/rllib/agents/dqn/simple_q_policy.py
+++ b/rllib/agents/dqn/simple_q_policy.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Basic example of a DQN policy without any optimizations."""
 
 from gym.spaces import Discrete
diff --git a/rllib/agents/es/es.py b/rllib/agents/es/es.py
index e4c8ddc2b..5a298ba3c 100644
--- a/rllib/agents/es/es.py
+++ b/rllib/agents/es/es.py
@@ -1,10 +1,6 @@
 # Code in this file is copied and adapted from
 # https://github.com/openai/evolution-strategies-starter.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import namedtuple
 import logging
 import numpy as np
diff --git a/rllib/agents/es/optimizers.py b/rllib/agents/es/optimizers.py
index 726a90635..d1a0f4f4d 100644
--- a/rllib/agents/es/optimizers.py
+++ b/rllib/agents/es/optimizers.py
@@ -1,10 +1,6 @@
 # Code in this file is copied and adapted from
 # https://github.com/openai/evolution-strategies-starter.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 
diff --git a/rllib/agents/es/policies.py b/rllib/agents/es/policies.py
index 8184bab5b..c4a80f9ce 100644
--- a/rllib/agents/es/policies.py
+++ b/rllib/agents/es/policies.py
@@ -1,10 +1,6 @@
 # Code in this file is copied and adapted from
 # https://github.com/openai/evolution-strategies-starter.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import numpy as np
 
diff --git a/rllib/agents/es/utils.py b/rllib/agents/es/utils.py
index 518fd3d00..2c18d07e4 100644
--- a/rllib/agents/es/utils.py
+++ b/rllib/agents/es/utils.py
@@ -1,10 +1,6 @@
 # Code in this file is copied and adapted from
 # https://github.com/openai/evolution-strategies-starter.
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 from ray.rllib.utils import try_import_tf
 
diff --git a/rllib/agents/impala/impala.py b/rllib/agents/impala/impala.py
index 6b3ef79e1..b2a313e93 100644
--- a/rllib/agents/impala/impala.py
+++ b/rllib/agents/impala/impala.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.a3c.a3c_tf_policy import A3CTFPolicy
 from ray.rllib.agents.impala.vtrace_policy import VTraceTFPolicy
 from ray.rllib.agents.trainer import Trainer, with_common_config
diff --git a/rllib/agents/impala/vtrace.py b/rllib/agents/impala/vtrace.py
index 6edc9f571..7d57814f9 100644
--- a/rllib/agents/impala/vtrace.py
+++ b/rllib/agents/impala/vtrace.py
@@ -28,10 +28,6 @@ multi_from_logits method accepts lists of tensors instead of just
 tensors.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 
 from ray.rllib.models.tf.tf_action_dist import Categorical
diff --git a/rllib/agents/impala/vtrace_policy.py b/rllib/agents/impala/vtrace_policy.py
index 17212aff4..9ed6d47aa 100644
--- a/rllib/agents/impala/vtrace_policy.py
+++ b/rllib/agents/impala/vtrace_policy.py
@@ -2,10 +2,6 @@
 
 Keep in sync with changes to A3CTFPolicy and VtraceSurrogatePolicy."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import logging
 import gym
diff --git a/rllib/agents/impala/vtrace_test.py b/rllib/agents/impala/vtrace_test.py
index e1f39991b..66a017bff 100644
--- a/rllib/agents/impala/vtrace_test.py
+++ b/rllib/agents/impala/vtrace_test.py
@@ -20,10 +20,6 @@ Importance Weighted Actor-Learner Architectures"
 by Espeholt, Soyer, Munos et al.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from absl.testing import parameterized
 import numpy as np
 import vtrace
diff --git a/rllib/agents/marwil/__init__.py b/rllib/agents/marwil/__init__.py
index 3d4a7cf2f..606115be4 100644
--- a/rllib/agents/marwil/__init__.py
+++ b/rllib/agents/marwil/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.marwil.marwil import MARWILTrainer, DEFAULT_CONFIG
 
 __all__ = ["MARWILTrainer", "DEFAULT_CONFIG"]
diff --git a/rllib/agents/marwil/marwil.py b/rllib/agents/marwil/marwil.py
index 29be38a84..702ff3d82 100644
--- a/rllib/agents/marwil/marwil.py
+++ b/rllib/agents/marwil/marwil.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.trainer import with_common_config
 from ray.rllib.agents.trainer_template import build_trainer
 from ray.rllib.agents.marwil.marwil_policy import MARWILPolicy
diff --git a/rllib/agents/marwil/marwil_policy.py b/rllib/agents/marwil/marwil_policy.py
index f271b78d2..eaae6d47b 100644
--- a/rllib/agents/marwil/marwil_policy.py
+++ b/rllib/agents/marwil/marwil_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.rllib.models import ModelCatalog
 from ray.rllib.evaluation.postprocessing import compute_advantages, \
diff --git a/rllib/agents/mock.py b/rllib/agents/mock.py
index 53f2c1205..abb05e2e5 100644
--- a/rllib/agents/mock.py
+++ b/rllib/agents/mock.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import pickle
 import numpy as np
diff --git a/rllib/agents/ppo/appo.py b/rllib/agents/ppo/appo.py
index 23b721d8b..585af32c8 100644
--- a/rllib/agents/ppo/appo.py
+++ b/rllib/agents/ppo/appo.py
@@ -1,91 +1,87 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-from ray.rllib.agents.ppo.appo_policy import AsyncPPOTFPolicy
-from ray.rllib.agents.trainer import with_base_config
-from ray.rllib.agents.ppo.ppo import update_kl
-from ray.rllib.agents import impala
-
-# yapf: disable
-# __sphinx_doc_begin__
-DEFAULT_CONFIG = with_base_config(impala.DEFAULT_CONFIG, {
-    # Whether to use V-trace weighted advantages. If false, PPO GAE advantages
-    # will be used instead.
-    "vtrace": False,
-
-    # == These two options only apply if vtrace: False ==
-    # If true, use the Generalized Advantage Estimator (GAE)
-    # with a value function, see https://arxiv.org/pdf/1506.02438.pdf.
-    "use_gae": True,
-    # GAE(lambda) parameter
-    "lambda": 1.0,
-
-    # == PPO surrogate loss options ==
-    "clip_param": 0.4,
-
-    # == PPO KL Loss options ==
-    "use_kl_loss": False,
-    "kl_coeff": 1.0,
-    "kl_target": 0.01,
-
-    # == IMPALA optimizer params (see documentation in impala.py) ==
-    "sample_batch_size": 50,
-    "train_batch_size": 500,
-    "min_iter_time_s": 10,
-    "num_workers": 2,
-    "num_gpus": 0,
-    "num_data_loader_buffers": 1,
-    "minibatch_buffer_size": 1,
-    "num_sgd_iter": 1,
-    "replay_proportion": 0.0,
-    "replay_buffer_num_slots": 100,
-    "learner_queue_size": 16,
-    "learner_queue_timeout": 300,
-    "max_sample_requests_in_flight_per_worker": 2,
-    "broadcast_interval": 1,
-    "grad_clip": 40.0,
-    "opt_type": "adam",
-    "lr": 0.0005,
-    "lr_schedule": None,
-    "decay": 0.99,
-    "momentum": 0.0,
-    "epsilon": 0.1,
-    "vf_loss_coeff": 0.5,
-    "entropy_coeff": 0.01,
-    "entropy_coeff_schedule": None,
-})
-# __sphinx_doc_end__
-# yapf: enable
-
-
-def update_target_and_kl(trainer, fetches):
-    # Update the KL coeff depending on how many steps LearnerThread has stepped
-    # through
-    learner_steps = trainer.optimizer.learner.num_steps
-    if learner_steps >= trainer.target_update_frequency:
-
-        # Update Target Network
-        trainer.optimizer.learner.num_steps = 0
-        trainer.workers.local_worker().foreach_trainable_policy(
-            lambda p, _: p.update_target())
-
-        # Also update KL Coeff
-        if trainer.config["use_kl_loss"]:
-            update_kl(trainer, trainer.optimizer.learner.stats)
-
-
-def initialize_target(trainer):
-    trainer.workers.local_worker().foreach_trainable_policy(
-        lambda p, _: p.update_target())
-    trainer.target_update_frequency = trainer.config["num_sgd_iter"] \
-        * trainer.config["minibatch_buffer_size"]
-
-
-APPOTrainer = impala.ImpalaTrainer.with_updates(
-    name="APPO",
-    default_config=DEFAULT_CONFIG,
-    default_policy=AsyncPPOTFPolicy,
-    get_policy_class=lambda _: AsyncPPOTFPolicy,
-    after_init=initialize_target,
-    after_optimizer_step=update_target_and_kl)
+from ray.rllib.agents.ppo.appo_policy import AsyncPPOTFPolicy
+from ray.rllib.agents.trainer import with_base_config
+from ray.rllib.agents.ppo.ppo import update_kl
+from ray.rllib.agents import impala
+
+# yapf: disable
+# __sphinx_doc_begin__
+DEFAULT_CONFIG = with_base_config(impala.DEFAULT_CONFIG, {
+    # Whether to use V-trace weighted advantages. If false, PPO GAE advantages
+    # will be used instead.
+    "vtrace": False,
+
+    # == These two options only apply if vtrace: False ==
+    # If true, use the Generalized Advantage Estimator (GAE)
+    # with a value function, see https://arxiv.org/pdf/1506.02438.pdf.
+    "use_gae": True,
+    # GAE(lambda) parameter
+    "lambda": 1.0,
+
+    # == PPO surrogate loss options ==
+    "clip_param": 0.4,
+
+    # == PPO KL Loss options ==
+    "use_kl_loss": False,
+    "kl_coeff": 1.0,
+    "kl_target": 0.01,
+
+    # == IMPALA optimizer params (see documentation in impala.py) ==
+    "sample_batch_size": 50,
+    "train_batch_size": 500,
+    "min_iter_time_s": 10,
+    "num_workers": 2,
+    "num_gpus": 0,
+    "num_data_loader_buffers": 1,
+    "minibatch_buffer_size": 1,
+    "num_sgd_iter": 1,
+    "replay_proportion": 0.0,
+    "replay_buffer_num_slots": 100,
+    "learner_queue_size": 16,
+    "learner_queue_timeout": 300,
+    "max_sample_requests_in_flight_per_worker": 2,
+    "broadcast_interval": 1,
+    "grad_clip": 40.0,
+    "opt_type": "adam",
+    "lr": 0.0005,
+    "lr_schedule": None,
+    "decay": 0.99,
+    "momentum": 0.0,
+    "epsilon": 0.1,
+    "vf_loss_coeff": 0.5,
+    "entropy_coeff": 0.01,
+    "entropy_coeff_schedule": None,
+})
+# __sphinx_doc_end__
+# yapf: enable
+
+
+def update_target_and_kl(trainer, fetches):
+    # Update the KL coeff depending on how many steps LearnerThread has stepped
+    # through
+    learner_steps = trainer.optimizer.learner.num_steps
+    if learner_steps >= trainer.target_update_frequency:
+
+        # Update Target Network
+        trainer.optimizer.learner.num_steps = 0
+        trainer.workers.local_worker().foreach_trainable_policy(
+            lambda p, _: p.update_target())
+
+        # Also update KL Coeff
+        if trainer.config["use_kl_loss"]:
+            update_kl(trainer, trainer.optimizer.learner.stats)
+
+
+def initialize_target(trainer):
+    trainer.workers.local_worker().foreach_trainable_policy(
+        lambda p, _: p.update_target())
+    trainer.target_update_frequency = trainer.config["num_sgd_iter"] \
+        * trainer.config["minibatch_buffer_size"]
+
+
+APPOTrainer = impala.ImpalaTrainer.with_updates(
+    name="APPO",
+    default_config=DEFAULT_CONFIG,
+    default_policy=AsyncPPOTFPolicy,
+    get_policy_class=lambda _: AsyncPPOTFPolicy,
+    after_init=initialize_target,
+    after_optimizer_step=update_target_and_kl)
diff --git a/rllib/agents/ppo/appo_policy.py b/rllib/agents/ppo/appo_policy.py
index 1d2f899e5..46094b69f 100644
--- a/rllib/agents/ppo/appo_policy.py
+++ b/rllib/agents/ppo/appo_policy.py
@@ -2,10 +2,6 @@
 
 Keep in sync with changes to VTraceTFPolicy."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import logging
 import gym
diff --git a/rllib/agents/ppo/ppo.py b/rllib/agents/ppo/ppo.py
index ee3a2eb20..8bf3ef451 100644
--- a/rllib/agents/ppo/ppo.py
+++ b/rllib/agents/ppo/ppo.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from ray.rllib.agents import with_common_config
diff --git a/rllib/agents/ppo/ppo_policy.py b/rllib/agents/ppo/ppo_policy.py
index 4821c97db..ef611ab92 100644
--- a/rllib/agents/ppo/ppo_policy.py
+++ b/rllib/agents/ppo/ppo_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 import ray
diff --git a/rllib/agents/ppo/test/test.py b/rllib/agents/ppo/test/test.py
index 7acbab41d..e8a604d16 100644
--- a/rllib/agents/ppo/test/test.py
+++ b/rllib/agents/ppo/test/test.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 import numpy as np
 from numpy.testing import assert_allclose
diff --git a/rllib/agents/ppo/utils.py b/rllib/agents/ppo/utils.py
index e97dce5cf..a6890c4b4 100644
--- a/rllib/agents/ppo/utils.py
+++ b/rllib/agents/ppo/utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 
diff --git a/rllib/agents/qmix/__init__.py b/rllib/agents/qmix/__init__.py
index 0de9ff272..9fe2cf8dd 100644
--- a/rllib/agents/qmix/__init__.py
+++ b/rllib/agents/qmix/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.qmix.qmix import QMixTrainer, DEFAULT_CONFIG
 from ray.rllib.agents.qmix.apex import ApexQMixTrainer
 
diff --git a/rllib/agents/qmix/apex.py b/rllib/agents/qmix/apex.py
index aac5d83f7..bfcfcaa08 100644
--- a/rllib/agents/qmix/apex.py
+++ b/rllib/agents/qmix/apex.py
@@ -1,9 +1,5 @@
 """Experimental: scalable Ape-X variant of QMIX"""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.dqn.apex import APEX_TRAINER_PROPERTIES
 from ray.rllib.agents.qmix.qmix import QMixTrainer, \
     DEFAULT_CONFIG as QMIX_CONFIG
diff --git a/rllib/agents/qmix/mixers.py b/rllib/agents/qmix/mixers.py
index 1e91622c0..3e05a0dba 100644
--- a/rllib/agents/qmix/mixers.py
+++ b/rllib/agents/qmix/mixers.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.utils.framework import try_import_torch
diff --git a/rllib/agents/qmix/model.py b/rllib/agents/qmix/model.py
index e5e5e9c86..41d4d01d6 100644
--- a/rllib/agents/qmix/model.py
+++ b/rllib/agents/qmix/model.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.preprocessors import get_preprocessor
 from ray.rllib.models.torch.torch_modelv2 import TorchModelV2
 from ray.rllib.utils.annotations import override
diff --git a/rllib/agents/qmix/qmix.py b/rllib/agents/qmix/qmix.py
index a6cb70e2c..b4495c6c6 100644
--- a/rllib/agents/qmix/qmix.py
+++ b/rllib/agents/qmix/qmix.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.trainer import with_common_config
 from ray.rllib.agents.dqn.dqn import GenericOffPolicyTrainer
 from ray.rllib.agents.qmix.qmix_policy import QMixTorchPolicy
diff --git a/rllib/agents/qmix/qmix_policy.py b/rllib/agents/qmix/qmix_policy.py
index 407e5e821..f1db486d3 100644
--- a/rllib/agents/qmix/qmix_policy.py
+++ b/rllib/agents/qmix/qmix_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from gym.spaces import Tuple, Discrete, Dict
 import logging
 import numpy as np
diff --git a/rllib/agents/registry.py b/rllib/agents/registry.py
index bb7e26168..35bd160ba 100644
--- a/rllib/agents/registry.py
+++ b/rllib/agents/registry.py
@@ -1,9 +1,5 @@
 """Registry of algorithm names for `rllib train --run=<alg_name>`"""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import traceback
 
 from ray.rllib.contrib.registry import CONTRIBUTED_ALGORITHMS
diff --git a/rllib/agents/sac/__init__.py b/rllib/agents/sac/__init__.py
index b938749c4..a9ea95da6 100644
--- a/rllib/agents/sac/__init__.py
+++ b/rllib/agents/sac/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.sac.sac import SACTrainer, DEFAULT_CONFIG
 from ray.rllib.utils import renamed_agent
 
diff --git a/rllib/agents/sac/sac.py b/rllib/agents/sac/sac.py
index 2573b4c26..88af30799 100644
--- a/rllib/agents/sac/sac.py
+++ b/rllib/agents/sac/sac.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.trainer import with_common_config
 from ray.rllib.agents.dqn.dqn import GenericOffPolicyTrainer
 from ray.rllib.agents.sac.sac_policy import SACTFPolicy
diff --git a/rllib/agents/sac/sac_model.py b/rllib/agents/sac/sac_model.py
index 93787b535..78e268ee0 100644
--- a/rllib/agents/sac/sac_model.py
+++ b/rllib/agents/sac/sac_model.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.models.tf.tf_modelv2 import TFModelV2
diff --git a/rllib/agents/sac/sac_policy.py b/rllib/agents/sac/sac_policy.py
index 99357b7a7..73ed56d01 100644
--- a/rllib/agents/sac/sac_policy.py
+++ b/rllib/agents/sac/sac_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from gym.spaces import Box
 import numpy as np
 import logging
diff --git a/rllib/agents/trainer.py b/rllib/agents/trainer.py
index 7f068c4af..01dd1e20e 100644
--- a/rllib/agents/trainer.py
+++ b/rllib/agents/trainer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from datetime import datetime
 import copy
 import logging
diff --git a/rllib/agents/trainer_template.py b/rllib/agents/trainer_template.py
index 638e92ec4..6006a31fc 100644
--- a/rllib/agents/trainer_template.py
+++ b/rllib/agents/trainer_template.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import time
 
 from ray.rllib.agents.trainer import Trainer, COMMON_CONFIG
diff --git a/rllib/contrib/alpha_zero/core/alpha_zero_trainer.py b/rllib/contrib/alpha_zero/core/alpha_zero_trainer.py
index 5c19dcdf4..d523195d9 100644
--- a/rllib/contrib/alpha_zero/core/alpha_zero_trainer.py
+++ b/rllib/contrib/alpha_zero/core/alpha_zero_trainer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from ray.rllib.agents import with_common_config
diff --git a/rllib/contrib/alpha_zero/examples/train_cartpole.py b/rllib/contrib/alpha_zero/examples/train_cartpole.py
index 8b9cbeecd..049882078 100644
--- a/rllib/contrib/alpha_zero/examples/train_cartpole.py
+++ b/rllib/contrib/alpha_zero/examples/train_cartpole.py
@@ -1,9 +1,5 @@
 """Example of using training on CartPole."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 
 from ray import tune
diff --git a/rllib/contrib/maddpg/__init__.py b/rllib/contrib/maddpg/__init__.py
index 90586a267..f4a19d305 100644
--- a/rllib/contrib/maddpg/__init__.py
+++ b/rllib/contrib/maddpg/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.contrib.maddpg.maddpg import MADDPGTrainer, DEFAULT_CONFIG
 
 __all__ = ["MADDPGTrainer", "DEFAULT_CONFIG"]
diff --git a/rllib/contrib/maddpg/maddpg.py b/rllib/contrib/maddpg/maddpg.py
index 74f0cd2e4..16f8dbc4b 100644
--- a/rllib/contrib/maddpg/maddpg.py
+++ b/rllib/contrib/maddpg/maddpg.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Contributed port of MADDPG from OpenAI baselines.
 
 The implementation has a couple assumptions:
diff --git a/rllib/contrib/maddpg/maddpg_policy.py b/rllib/contrib/maddpg/maddpg_policy.py
index 60befde05..6258b6038 100644
--- a/rllib/contrib/maddpg/maddpg_policy.py
+++ b/rllib/contrib/maddpg/maddpg_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.rllib.agents.dqn.dqn_policy import minimize_and_clip, _adjust_nstep
 from ray.rllib.evaluation.metrics import LEARNER_STATS_KEY
diff --git a/rllib/contrib/random_agent/random_agent.py b/rllib/contrib/random_agent/random_agent.py
index 17b4c8d09..1a714dff0 100644
--- a/rllib/contrib/random_agent/random_agent.py
+++ b/rllib/contrib/random_agent/random_agent.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.agents.trainer import Trainer, with_common_config
diff --git a/rllib/contrib/registry.py b/rllib/contrib/registry.py
index 05c456d23..f2c0fca49 100644
--- a/rllib/contrib/registry.py
+++ b/rllib/contrib/registry.py
@@ -1,9 +1,5 @@
 """Registry of algorithm names for `rllib train --run=<alg_name>`"""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 
 def _import_random_agent():
     from ray.rllib.contrib.random_agent.random_agent import RandomAgent
diff --git a/rllib/env/base_env.py b/rllib/env/base_env.py
index f862e5c2a..29c2e3a9c 100644
--- a/rllib/env/base_env.py
+++ b/rllib/env/base_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.env.external_env import ExternalEnv
 from ray.rllib.env.external_multi_agent_env import ExternalMultiAgentEnv
 from ray.rllib.env.vector_env import VectorEnv
diff --git a/rllib/env/constants.py b/rllib/env/constants.py
index 2b6c460f5..45c9b7119 100644
--- a/rllib/env/constants.py
+++ b/rllib/env/constants.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 # info key for the individual rewards of an agent, for example:
 # info: {
 #   group_1: {
diff --git a/rllib/env/dm_env_wrapper.py b/rllib/env/dm_env_wrapper.py
index 37c9df7dc..e402c4cc6 100644
--- a/rllib/env/dm_env_wrapper.py
+++ b/rllib/env/dm_env_wrapper.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 from gym import spaces
 
diff --git a/rllib/env/env_context.py b/rllib/env/env_context.py
index 3a9101ab6..1507cd51f 100644
--- a/rllib/env/env_context.py
+++ b/rllib/env/env_context.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils.annotations import PublicAPI
 
 
diff --git a/rllib/env/external_env.py b/rllib/env/external_env.py
index 562b87418..89b1c544f 100644
--- a/rllib/env/external_env.py
+++ b/rllib/env/external_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from six.moves import queue
 import threading
 import uuid
diff --git a/rllib/env/external_multi_agent_env.py b/rllib/env/external_multi_agent_env.py
index cd892ba72..414679274 100644
--- a/rllib/env/external_multi_agent_env.py
+++ b/rllib/env/external_multi_agent_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import uuid
 
 from ray.rllib.utils.annotations import override, PublicAPI
diff --git a/rllib/env/group_agents_wrapper.py b/rllib/env/group_agents_wrapper.py
index 8f6051bf0..375033f14 100644
--- a/rllib/env/group_agents_wrapper.py
+++ b/rllib/env/group_agents_wrapper.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import OrderedDict
 
 from ray.rllib.env.constants import GROUP_REWARDS, GROUP_INFO
diff --git a/rllib/env/multi_agent_env.py b/rllib/env/multi_agent_env.py
index 7b1f5ce5d..bfe147b5d 100644
--- a/rllib/env/multi_agent_env.py
+++ b/rllib/env/multi_agent_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils.annotations import PublicAPI
 
 
diff --git a/rllib/env/remote_vector_env.py b/rllib/env/remote_vector_env.py
index d6d6da154..9b2ddd019 100644
--- a/rllib/env/remote_vector_env.py
+++ b/rllib/env/remote_vector_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 import ray
diff --git a/rllib/env/serving_env.py b/rllib/env/serving_env.py
index cb976bf80..b14f6800f 100644
--- a/rllib/env/serving_env.py
+++ b/rllib/env/serving_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.env.external_env import ExternalEnv
 
 # renamed to ExternalEnv in 0.6
diff --git a/rllib/env/vector_env.py b/rllib/env/vector_env.py
index 66bd8e737..4528c9922 100644
--- a/rllib/env/vector_env.py
+++ b/rllib/env/vector_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 
diff --git a/rllib/evaluation/episode.py b/rllib/evaluation/episode.py
index ab4746b79..28e91efde 100644
--- a/rllib/evaluation/episode.py
+++ b/rllib/evaluation/episode.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import defaultdict
 import random
 
diff --git a/rllib/evaluation/interface.py b/rllib/evaluation/interface.py
index 739aa55b1..c8143726f 100644
--- a/rllib/evaluation/interface.py
+++ b/rllib/evaluation/interface.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 
 from ray.rllib.utils.annotations import DeveloperAPI
diff --git a/rllib/evaluation/metrics.py b/rllib/evaluation/metrics.py
index 6f9eda1f2..51219ad6c 100644
--- a/rllib/evaluation/metrics.py
+++ b/rllib/evaluation/metrics.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 import collections
diff --git a/rllib/evaluation/policy_evaluator.py b/rllib/evaluation/policy_evaluator.py
index 18dec8abc..a61d4b254 100644
--- a/rllib/evaluation/policy_evaluator.py
+++ b/rllib/evaluation/policy_evaluator.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils import renamed_class
 from ray.rllib.evaluation import RolloutWorker
 
diff --git a/rllib/evaluation/policy_graph.py b/rllib/evaluation/policy_graph.py
index 5d0fdf2a4..68f6cc5a9 100644
--- a/rllib/evaluation/policy_graph.py
+++ b/rllib/evaluation/policy_graph.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.policy.policy import Policy
 from ray.rllib.utils import renamed_class
 
diff --git a/rllib/evaluation/postprocessing.py b/rllib/evaluation/postprocessing.py
index 46a19b929..acb201781 100644
--- a/rllib/evaluation/postprocessing.py
+++ b/rllib/evaluation/postprocessing.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import scipy.signal
 from ray.rllib.policy.sample_batch import SampleBatch
diff --git a/rllib/evaluation/rollout_metrics.py b/rllib/evaluation/rollout_metrics.py
index fbb57f953..8e0f97b8b 100644
--- a/rllib/evaluation/rollout_metrics.py
+++ b/rllib/evaluation/rollout_metrics.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 
 # Define this in its own file, see #5125
diff --git a/rllib/evaluation/rollout_worker.py b/rllib/evaluation/rollout_worker.py
index 2d2a42899..ea3d0c822 100644
--- a/rllib/evaluation/rollout_worker.py
+++ b/rllib/evaluation/rollout_worker.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import random
 import numpy as np
 import gym
diff --git a/rllib/evaluation/sample_batch.py b/rllib/evaluation/sample_batch.py
index 2c0f119a9..740fff70c 100644
--- a/rllib/evaluation/sample_batch.py
+++ b/rllib/evaluation/sample_batch.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.policy.sample_batch import SampleBatch, MultiAgentBatch
 from ray.rllib.utils import renamed_class
 
diff --git a/rllib/evaluation/sample_batch_builder.py b/rllib/evaluation/sample_batch_builder.py
index 85e608c31..bb5bc3ceb 100644
--- a/rllib/evaluation/sample_batch_builder.py
+++ b/rllib/evaluation/sample_batch_builder.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import logging
 import numpy as np
diff --git a/rllib/evaluation/sampler.py b/rllib/evaluation/sampler.py
index 5917397ad..361462181 100644
--- a/rllib/evaluation/sampler.py
+++ b/rllib/evaluation/sampler.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import defaultdict, namedtuple
 import logging
 import numpy as np
diff --git a/rllib/evaluation/tf_policy_graph.py b/rllib/evaluation/tf_policy_graph.py
index 2c4955a17..8d4895473 100644
--- a/rllib/evaluation/tf_policy_graph.py
+++ b/rllib/evaluation/tf_policy_graph.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.policy.tf_policy import TFPolicy
 from ray.rllib.utils import renamed_class
 
diff --git a/rllib/evaluation/torch_policy_graph.py b/rllib/evaluation/torch_policy_graph.py
index 08cc29fed..6eaa7d71b 100644
--- a/rllib/evaluation/torch_policy_graph.py
+++ b/rllib/evaluation/torch_policy_graph.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.policy.torch_policy import TorchPolicy
 from ray.rllib.utils import renamed_class
 
diff --git a/rllib/evaluation/worker_set.py b/rllib/evaluation/worker_set.py
index e3c39c48e..a1798951f 100644
--- a/rllib/evaluation/worker_set.py
+++ b/rllib/evaluation/worker_set.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 from types import FunctionType
 
diff --git a/rllib/examples/autoregressive_action_dist.py b/rllib/examples/autoregressive_action_dist.py
index 5a6c0fa86..2a60de2c2 100644
--- a/rllib/examples/autoregressive_action_dist.py
+++ b/rllib/examples/autoregressive_action_dist.py
@@ -10,10 +10,6 @@ pattern, and a custom action distribution class that leverages that model.
 This examples shows both.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 from gym.spaces import Discrete, Tuple
 import argparse
diff --git a/rllib/examples/batch_norm_model.py b/rllib/examples/batch_norm_model.py
index cabbda54f..dd37a1eec 100644
--- a/rllib/examples/batch_norm_model.py
+++ b/rllib/examples/batch_norm_model.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Example of using a custom model with batch norm."""
 
 import argparse
diff --git a/rllib/examples/centralized_critic.py b/rllib/examples/centralized_critic.py
index a9aa5fc23..9a5fdb54e 100644
--- a/rllib/examples/centralized_critic.py
+++ b/rllib/examples/centralized_critic.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """An example of customizing PPO to leverage a centralized critic.
 
 Here the model and policy are hard-coded to implement a centralized critic
diff --git a/rllib/examples/centralized_critic_2.py b/rllib/examples/centralized_critic_2.py
index 1174052e6..529a82359 100644
--- a/rllib/examples/centralized_critic_2.py
+++ b/rllib/examples/centralized_critic_2.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """An example of implementing a centralized critic by modifying the env.
 
 The advantage of this approach is that it's very simple and you don't have to
diff --git a/rllib/examples/custom_env.py b/rllib/examples/custom_env.py
index 15e3c6ce7..51de41c53 100644
--- a/rllib/examples/custom_env.py
+++ b/rllib/examples/custom_env.py
@@ -8,10 +8,6 @@ This example shows:
 You can visualize experiment results in ~/ray_results using TensorBoard.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import gym
 from ray.rllib.models import ModelCatalog
diff --git a/rllib/examples/custom_fast_model.py b/rllib/examples/custom_fast_model.py
index dce01e9e7..2d6572992 100644
--- a/rllib/examples/custom_fast_model.py
+++ b/rllib/examples/custom_fast_model.py
@@ -4,10 +4,6 @@ Both the model and env are trivial (and super-fast), so they are useful
 for running perf microbenchmarks.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from gym.spaces import Discrete, Box
 import gym
 import numpy as np
diff --git a/rllib/examples/custom_keras_model.py b/rllib/examples/custom_keras_model.py
index 465af255d..580c543c6 100644
--- a/rllib/examples/custom_keras_model.py
+++ b/rllib/examples/custom_keras_model.py
@@ -1,9 +1,5 @@
 """Example of using a custom ModelV2 Keras-style model."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 
 import ray
diff --git a/rllib/examples/custom_keras_rnn_model.py b/rllib/examples/custom_keras_rnn_model.py
index 791cb487e..0dcc3e5f8 100644
--- a/rllib/examples/custom_keras_rnn_model.py
+++ b/rllib/examples/custom_keras_rnn_model.py
@@ -1,9 +1,5 @@
 """Example of using a custom RNN keras model."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 from gym.spaces import Discrete
 import numpy as np
diff --git a/rllib/examples/custom_loss.py b/rllib/examples/custom_loss.py
index ee2f3b896..ef304f752 100644
--- a/rllib/examples/custom_loss.py
+++ b/rllib/examples/custom_loss.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Example of using custom_loss() with an imitation learning loss.
 
 The default input file is too small to learn a good policy, but you can
diff --git a/rllib/examples/custom_tf_policy.py b/rllib/examples/custom_tf_policy.py
index abeddd187..b036fc314 100644
--- a/rllib/examples/custom_tf_policy.py
+++ b/rllib/examples/custom_tf_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 
 import ray
diff --git a/rllib/examples/custom_torch_policy.py b/rllib/examples/custom_torch_policy.py
index 7be747440..1e0988152 100644
--- a/rllib/examples/custom_torch_policy.py
+++ b/rllib/examples/custom_torch_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 
 import ray
diff --git a/rllib/examples/custom_train_fn.py b/rllib/examples/custom_train_fn.py
index cc7b55e70..9707a2dbf 100644
--- a/rllib/examples/custom_train_fn.py
+++ b/rllib/examples/custom_train_fn.py
@@ -6,10 +6,6 @@ This example shows:
 You can visualize experiment results in ~/ray_results using TensorBoard.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray import tune
 from ray.rllib.agents.ppo import PPOTrainer
diff --git a/rllib/examples/dmlab_watermaze.py b/rllib/examples/dmlab_watermaze.py
index 5a23357b9..47b4d2ca7 100644
--- a/rllib/examples/dmlab_watermaze.py
+++ b/rllib/examples/dmlab_watermaze.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from deepmind_lab import dmenv_module
 
 from ray.rllib import env
diff --git a/rllib/examples/eager_execution.py b/rllib/examples/eager_execution.py
index fe2305207..f125c56c4 100644
--- a/rllib/examples/eager_execution.py
+++ b/rllib/examples/eager_execution.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import random
 
diff --git a/rllib/examples/export/cartpole_dqn_export.py b/rllib/examples/export/cartpole_dqn_export.py
index 47a5e3b41..adaaf2bea 100644
--- a/rllib/examples/export/cartpole_dqn_export.py
+++ b/rllib/examples/export/cartpole_dqn_export.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import ray
 
diff --git a/rllib/examples/hierarchical_training.py b/rllib/examples/hierarchical_training.py
index 2fe61953d..8fb09a5fe 100644
--- a/rllib/examples/hierarchical_training.py
+++ b/rllib/examples/hierarchical_training.py
@@ -22,10 +22,6 @@ Note that the hierarchical formulation actually converges slightly slower than
 using --flat in this example.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import random
 import gym
diff --git a/rllib/examples/multiagent_cartpole.py b/rllib/examples/multiagent_cartpole.py
index 6cc00bdeb..b108a4ff2 100644
--- a/rllib/examples/multiagent_cartpole.py
+++ b/rllib/examples/multiagent_cartpole.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Simple example of setting up a multi-agent policy mapping.
 
 Control the number of agents and policies via --num-agents and --num-policies.
diff --git a/rllib/examples/multiagent_custom_policy.py b/rllib/examples/multiagent_custom_policy.py
index b19dbfb3d..54b1506f1 100644
--- a/rllib/examples/multiagent_custom_policy.py
+++ b/rllib/examples/multiagent_custom_policy.py
@@ -13,10 +13,6 @@ Result for PG_multi_cartpole_0:
   ...
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import gym
 
diff --git a/rllib/examples/multiagent_two_trainers.py b/rllib/examples/multiagent_two_trainers.py
index cdac4a2fd..be3b102b4 100644
--- a/rllib/examples/multiagent_two_trainers.py
+++ b/rllib/examples/multiagent_two_trainers.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Example of using two different training methods at once in multi-agent.
 
 Here we create a number of CartPole agents, some of which are trained with
diff --git a/rllib/examples/parametric_action_cartpole.py b/rllib/examples/parametric_action_cartpole.py
index 12c4f2e75..dd1eb5c6f 100644
--- a/rllib/examples/parametric_action_cartpole.py
+++ b/rllib/examples/parametric_action_cartpole.py
@@ -14,10 +14,6 @@ algorithms might crash if they don't properly ignore the -inf action scores.
 Working configurations are given below.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import random
 import numpy as np
diff --git a/rllib/examples/rock_paper_scissors_multiagent.py b/rllib/examples/rock_paper_scissors_multiagent.py
index 411d419b1..fbfa92aab 100644
--- a/rllib/examples/rock_paper_scissors_multiagent.py
+++ b/rllib/examples/rock_paper_scissors_multiagent.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """A simple multi-agent env with two agents playing rock paper scissors.
 
 This demonstrates running the following policies in competition:
diff --git a/rllib/examples/rollout_worker_custom_workflow.py b/rllib/examples/rollout_worker_custom_workflow.py
index fd1adc851..837a7feb7 100644
--- a/rllib/examples/rollout_worker_custom_workflow.py
+++ b/rllib/examples/rollout_worker_custom_workflow.py
@@ -5,10 +5,6 @@ a custom Policy class and manually coordinate distributed sample
 collection and policy optimization.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import gym
 
diff --git a/rllib/examples/saving_experiences.py b/rllib/examples/saving_experiences.py
index d2de88302..6ad53570d 100644
--- a/rllib/examples/saving_experiences.py
+++ b/rllib/examples/saving_experiences.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Simple example of writing experiences to a file using JsonWriter."""
 
 # __sphinx_doc_begin__
diff --git a/rllib/examples/serving/cartpole_client.py b/rllib/examples/serving/cartpole_client.py
index b116eb9aa..ce2448b7b 100755
--- a/rllib/examples/serving/cartpole_client.py
+++ b/rllib/examples/serving/cartpole_client.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Example of querying a policy server. Copy this file for your use case.
 
 To try this out, in two separate shells run:
diff --git a/rllib/examples/serving/cartpole_server.py b/rllib/examples/serving/cartpole_server.py
index c9c794c3a..f72d5149c 100755
--- a/rllib/examples/serving/cartpole_server.py
+++ b/rllib/examples/serving/cartpole_server.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Example of running a policy server. Copy this file for your use case.
 
 To try this out, in two separate shells run:
diff --git a/rllib/examples/twostep_game.py b/rllib/examples/twostep_game.py
index 37e622390..045c3a2e1 100644
--- a/rllib/examples/twostep_game.py
+++ b/rllib/examples/twostep_game.py
@@ -9,10 +9,6 @@ Configurations you can try:
 See also: centralized_critic.py for centralized critic PPO on this game.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 from gym.spaces import Tuple, MultiDiscrete, Dict, Discrete
 import numpy as np
diff --git a/rllib/models/action_dist.py b/rllib/models/action_dist.py
index 0b88547d2..e6e21dde2 100644
--- a/rllib/models/action_dist.py
+++ b/rllib/models/action_dist.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils.annotations import DeveloperAPI
 
 
diff --git a/rllib/models/catalog.py b/rllib/models/catalog.py
index c8f1711ff..71f90dc18 100644
--- a/rllib/models/catalog.py
+++ b/rllib/models/catalog.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import logging
 import numpy as np
diff --git a/rllib/models/model.py b/rllib/models/model.py
index bfc2e7a65..52499c73b 100644
--- a/rllib/models/model.py
+++ b/rllib/models/model.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import OrderedDict
 import logging
 import gym
diff --git a/rllib/models/modelv2.py b/rllib/models/modelv2.py
index 14165607f..3435f269e 100644
--- a/rllib/models/modelv2.py
+++ b/rllib/models/modelv2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.policy.sample_batch import SampleBatch
 from ray.rllib.models.model import restore_original_dimensions, flatten
 from ray.rllib.utils.annotations import PublicAPI
diff --git a/rllib/models/preprocessors.py b/rllib/models/preprocessors.py
index 2bf567963..88b253269 100644
--- a/rllib/models/preprocessors.py
+++ b/rllib/models/preprocessors.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import OrderedDict
 import cv2
 import logging
diff --git a/rllib/models/tf/fcnet_v1.py b/rllib/models/tf/fcnet_v1.py
index d4f645ab0..d2d182b36 100644
--- a/rllib/models/tf/fcnet_v1.py
+++ b/rllib/models/tf/fcnet_v1.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.model import Model
 from ray.rllib.models.tf.misc import normc_initializer, get_activation_fn
 from ray.rllib.utils.annotations import override
diff --git a/rllib/models/tf/fcnet_v2.py b/rllib/models/tf/fcnet_v2.py
index 2932659c5..5f69b3b1b 100644
--- a/rllib/models/tf/fcnet_v2.py
+++ b/rllib/models/tf/fcnet_v2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.models.tf.tf_modelv2 import TFModelV2
diff --git a/rllib/models/tf/lstm_v1.py b/rllib/models/tf/lstm_v1.py
index f6ba42d56..eea2fb686 100644
--- a/rllib/models/tf/lstm_v1.py
+++ b/rllib/models/tf/lstm_v1.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.models.model import Model
diff --git a/rllib/models/tf/misc.py b/rllib/models/tf/misc.py
index 0e62783f3..8416f1c15 100644
--- a/rllib/models/tf/misc.py
+++ b/rllib/models/tf/misc.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 from ray.rllib.utils import try_import_tf
 
diff --git a/rllib/models/tf/modelv1_compat.py b/rllib/models/tf/modelv1_compat.py
index a2b1b54ab..85e8ddfb8 100644
--- a/rllib/models/tf/modelv1_compat.py
+++ b/rllib/models/tf/modelv1_compat.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 
diff --git a/rllib/models/tf/recurrent_tf_modelv2.py b/rllib/models/tf/recurrent_tf_modelv2.py
index 2691a11ba..0ac567c8d 100644
--- a/rllib/models/tf/recurrent_tf_modelv2.py
+++ b/rllib/models/tf/recurrent_tf_modelv2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.modelv2 import ModelV2
 from ray.rllib.models.tf.tf_modelv2 import TFModelV2
 from ray.rllib.policy.rnn_sequencing import add_time_dimension
diff --git a/rllib/models/tf/tf_action_dist.py b/rllib/models/tf/tf_action_dist.py
index 573c18edd..f52faa1d2 100644
--- a/rllib/models/tf/tf_action_dist.py
+++ b/rllib/models/tf/tf_action_dist.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import functools
 
diff --git a/rllib/models/tf/tf_modelv2.py b/rllib/models/tf/tf_modelv2.py
index 27a8137ac..15877f30c 100644
--- a/rllib/models/tf/tf_modelv2.py
+++ b/rllib/models/tf/tf_modelv2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.modelv2 import ModelV2
 from ray.rllib.utils.annotations import PublicAPI
 from ray.rllib.utils import try_import_tf
diff --git a/rllib/models/tf/visionnet_v1.py b/rllib/models/tf/visionnet_v1.py
index 8eca33950..35e5a8b14 100644
--- a/rllib/models/tf/visionnet_v1.py
+++ b/rllib/models/tf/visionnet_v1.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.model import Model
 from ray.rllib.models.tf.misc import get_activation_fn, flatten
 from ray.rllib.utils.annotations import override
diff --git a/rllib/models/tf/visionnet_v2.py b/rllib/models/tf/visionnet_v2.py
index 21f01241e..729cab291 100644
--- a/rllib/models/tf/visionnet_v2.py
+++ b/rllib/models/tf/visionnet_v2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.tf.tf_modelv2 import TFModelV2
 from ray.rllib.models.tf.visionnet_v1 import _get_filter_config
 from ray.rllib.models.tf.misc import normc_initializer, get_activation_fn
diff --git a/rllib/models/torch/fcnet.py b/rllib/models/torch/fcnet.py
index b168f2ad2..cea59c384 100644
--- a/rllib/models/torch/fcnet.py
+++ b/rllib/models/torch/fcnet.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 
diff --git a/rllib/models/torch/misc.py b/rllib/models/torch/misc.py
index 806c646dd..edec3a148 100644
--- a/rllib/models/torch/misc.py
+++ b/rllib/models/torch/misc.py
@@ -1,8 +1,4 @@
 """ Code adapted from https://github.com/ikostrikov/pytorch-a3c"""
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.utils import try_import_torch
diff --git a/rllib/models/torch/torch_action_dist.py b/rllib/models/torch/torch_action_dist.py
index af0962733..9cdaec6c0 100644
--- a/rllib/models/torch/torch_action_dist.py
+++ b/rllib/models/torch/torch_action_dist.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.models.action_dist import ActionDistribution
diff --git a/rllib/models/torch/torch_modelv2.py b/rllib/models/torch/torch_modelv2.py
index cd279c7fc..ed34fcb90 100644
--- a/rllib/models/torch/torch_modelv2.py
+++ b/rllib/models/torch/torch_modelv2.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.modelv2 import ModelV2
 from ray.rllib.utils.annotations import PublicAPI
 from ray.rllib.utils import try_import_torch
diff --git a/rllib/models/torch/visionnet.py b/rllib/models/torch/visionnet.py
index 077809802..dc9c53321 100644
--- a/rllib/models/torch/visionnet.py
+++ b/rllib/models/torch/visionnet.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.models.torch.torch_modelv2 import TorchModelV2
 from ray.rllib.models.torch.misc import normc_initializer, valid_padding, \
     SlimConv2d, SlimFC
diff --git a/rllib/offline/__init__.py b/rllib/offline/__init__.py
index a40da6c5b..69b07c657 100644
--- a/rllib/offline/__init__.py
+++ b/rllib/offline/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.offline.io_context import IOContext
 from ray.rllib.offline.json_reader import JsonReader
 from ray.rllib.offline.json_writer import JsonWriter
diff --git a/rllib/offline/input_reader.py b/rllib/offline/input_reader.py
index 240c4b3b1..ab22825b5 100644
--- a/rllib/offline/input_reader.py
+++ b/rllib/offline/input_reader.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 import threading
diff --git a/rllib/offline/io_context.py b/rllib/offline/io_context.py
index 183bd5994..3b4083426 100644
--- a/rllib/offline/io_context.py
+++ b/rllib/offline/io_context.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 
 from ray.rllib.utils.annotations import PublicAPI
diff --git a/rllib/offline/is_estimator.py b/rllib/offline/is_estimator.py
index 55678c951..7ea542b30 100644
--- a/rllib/offline/is_estimator.py
+++ b/rllib/offline/is_estimator.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.offline.off_policy_estimator import OffPolicyEstimator, \
     OffPolicyEstimate
 from ray.rllib.utils.annotations import override
diff --git a/rllib/offline/json_reader.py b/rllib/offline/json_reader.py
index 35d28669d..c1eefdd00 100644
--- a/rllib/offline/json_reader.py
+++ b/rllib/offline/json_reader.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import glob
 import json
 import logging
diff --git a/rllib/offline/json_writer.py b/rllib/offline/json_writer.py
index cf2009e3d..47df20329 100644
--- a/rllib/offline/json_writer.py
+++ b/rllib/offline/json_writer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from datetime import datetime
 import json
 import logging
diff --git a/rllib/offline/mixed_input.py b/rllib/offline/mixed_input.py
index 1cdf75a84..6c00b043c 100644
--- a/rllib/offline/mixed_input.py
+++ b/rllib/offline/mixed_input.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.offline.input_reader import InputReader
diff --git a/rllib/offline/off_policy_estimator.py b/rllib/offline/off_policy_estimator.py
index c90bcaec9..093d050d7 100644
--- a/rllib/offline/off_policy_estimator.py
+++ b/rllib/offline/off_policy_estimator.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import namedtuple
 import logging
 
diff --git a/rllib/offline/output_writer.py b/rllib/offline/output_writer.py
index 13033b240..af7b92b66 100644
--- a/rllib/offline/output_writer.py
+++ b/rllib/offline/output_writer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils.annotations import override
 from ray.rllib.utils.annotations import PublicAPI
 
diff --git a/rllib/offline/shuffled_input.py b/rllib/offline/shuffled_input.py
index 22b4d6941..a29f03e1c 100644
--- a/rllib/offline/shuffled_input.py
+++ b/rllib/offline/shuffled_input.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import random
 
diff --git a/rllib/offline/wis_estimator.py b/rllib/offline/wis_estimator.py
index f538d3871..695c3dc35 100644
--- a/rllib/offline/wis_estimator.py
+++ b/rllib/offline/wis_estimator.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.offline.off_policy_estimator import OffPolicyEstimator, \
     OffPolicyEstimate
 from ray.rllib.utils.annotations import override
diff --git a/rllib/optimizers/aso_aggregator.py b/rllib/optimizers/aso_aggregator.py
index 7c5452bf0..51d4dcd12 100644
--- a/rllib/optimizers/aso_aggregator.py
+++ b/rllib/optimizers/aso_aggregator.py
@@ -1,9 +1,5 @@
 """Helper class for AsyncSamplesOptimizer."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import random
 
diff --git a/rllib/optimizers/aso_learner.py b/rllib/optimizers/aso_learner.py
index 16fc7cc82..23c72a3c0 100644
--- a/rllib/optimizers/aso_learner.py
+++ b/rllib/optimizers/aso_learner.py
@@ -1,9 +1,5 @@
 """Helper class for AsyncSamplesOptimizer."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import threading
 
 from six.moves import queue
diff --git a/rllib/optimizers/aso_minibatch_buffer.py b/rllib/optimizers/aso_minibatch_buffer.py
index d9fe447de..5a5cee850 100644
--- a/rllib/optimizers/aso_minibatch_buffer.py
+++ b/rllib/optimizers/aso_minibatch_buffer.py
@@ -1,9 +1,5 @@
 """Helper class for AsyncSamplesOptimizer."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 
 class MinibatchBuffer:
     """Ring buffer of recent data batches for minibatch SGD.
diff --git a/rllib/optimizers/aso_multi_gpu_learner.py b/rllib/optimizers/aso_multi_gpu_learner.py
index 80109edff..75fc39ba6 100644
--- a/rllib/optimizers/aso_multi_gpu_learner.py
+++ b/rllib/optimizers/aso_multi_gpu_learner.py
@@ -1,9 +1,5 @@
 """Helper class for AsyncSamplesOptimizer."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import threading
 import math
diff --git a/rllib/optimizers/aso_tree_aggregator.py b/rllib/optimizers/aso_tree_aggregator.py
index 45a8ad5f0..22460ab2c 100644
--- a/rllib/optimizers/aso_tree_aggregator.py
+++ b/rllib/optimizers/aso_tree_aggregator.py
@@ -1,9 +1,5 @@
 """Helper class for AsyncSamplesOptimizer."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import logging
 import os
diff --git a/rllib/optimizers/async_gradients_optimizer.py b/rllib/optimizers/async_gradients_optimizer.py
index 2a0d0a631..dcda7c494 100644
--- a/rllib/optimizers/async_gradients_optimizer.py
+++ b/rllib/optimizers/async_gradients_optimizer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.rllib.evaluation.metrics import get_learner_stats
 from ray.rllib.optimizers.policy_optimizer import PolicyOptimizer
diff --git a/rllib/optimizers/async_replay_optimizer.py b/rllib/optimizers/async_replay_optimizer.py
index 1ba650de5..a1a0d00dc 100644
--- a/rllib/optimizers/async_replay_optimizer.py
+++ b/rllib/optimizers/async_replay_optimizer.py
@@ -2,10 +2,6 @@
 
 https://arxiv.org/abs/1803.00933"""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import os
 import random
diff --git a/rllib/optimizers/async_samples_optimizer.py b/rllib/optimizers/async_samples_optimizer.py
index 8eab14f3f..36a3ce22d 100644
--- a/rllib/optimizers/async_samples_optimizer.py
+++ b/rllib/optimizers/async_samples_optimizer.py
@@ -2,10 +2,6 @@
 
 https://arxiv.org/abs/1802.01561"""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import time
 
diff --git a/rllib/optimizers/microbatch_optimizer.py b/rllib/optimizers/microbatch_optimizer.py
index c8bbdc04e..42b6ad807 100644
--- a/rllib/optimizers/microbatch_optimizer.py
+++ b/rllib/optimizers/microbatch_optimizer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 import ray
diff --git a/rllib/optimizers/multi_gpu_impl.py b/rllib/optimizers/multi_gpu_impl.py
index 3d27d6dbc..70d0a1514 100644
--- a/rllib/optimizers/multi_gpu_impl.py
+++ b/rllib/optimizers/multi_gpu_impl.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import namedtuple
 import logging
 
diff --git a/rllib/optimizers/multi_gpu_optimizer.py b/rllib/optimizers/multi_gpu_optimizer.py
index 3f6e19e5e..d844552b1 100644
--- a/rllib/optimizers/multi_gpu_optimizer.py
+++ b/rllib/optimizers/multi_gpu_optimizer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import math
 import numpy as np
diff --git a/rllib/optimizers/policy_optimizer.py b/rllib/optimizers/policy_optimizer.py
index d46f6e9a6..7f2582088 100644
--- a/rllib/optimizers/policy_optimizer.py
+++ b/rllib/optimizers/policy_optimizer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 from ray.rllib.utils.annotations import DeveloperAPI
diff --git a/rllib/optimizers/replay_buffer.py b/rllib/optimizers/replay_buffer.py
index 0b7f0979b..2f59c1d49 100644
--- a/rllib/optimizers/replay_buffer.py
+++ b/rllib/optimizers/replay_buffer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import random
 import sys
diff --git a/rllib/optimizers/rollout.py b/rllib/optimizers/rollout.py
index b329c1ee3..cc0a80a35 100644
--- a/rllib/optimizers/rollout.py
+++ b/rllib/optimizers/rollout.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 import ray
diff --git a/rllib/optimizers/segment_tree.py b/rllib/optimizers/segment_tree.py
index 271965bac..ac7e06481 100644
--- a/rllib/optimizers/segment_tree.py
+++ b/rllib/optimizers/segment_tree.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import operator
 
 
diff --git a/rllib/optimizers/sync_batch_replay_optimizer.py b/rllib/optimizers/sync_batch_replay_optimizer.py
index f241b0427..50b5411b0 100644
--- a/rllib/optimizers/sync_batch_replay_optimizer.py
+++ b/rllib/optimizers/sync_batch_replay_optimizer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import random
 
 import ray
diff --git a/rllib/optimizers/sync_replay_optimizer.py b/rllib/optimizers/sync_replay_optimizer.py
index bbd3e4f49..5ef061848 100644
--- a/rllib/optimizers/sync_replay_optimizer.py
+++ b/rllib/optimizers/sync_replay_optimizer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import collections
 import numpy as np
diff --git a/rllib/optimizers/sync_samples_optimizer.py b/rllib/optimizers/sync_samples_optimizer.py
index 7f8553e1a..90119076c 100644
--- a/rllib/optimizers/sync_samples_optimizer.py
+++ b/rllib/optimizers/sync_samples_optimizer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import random
 from collections import defaultdict
diff --git a/rllib/optimizers/tests/test_segment_tree.py b/rllib/optimizers/tests/test_segment_tree.py
index af53ffa33..d7a50cdf2 100644
--- a/rllib/optimizers/tests/test_segment_tree.py
+++ b/rllib/optimizers/tests/test_segment_tree.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.optimizers.segment_tree import SumSegmentTree, MinSegmentTree
diff --git a/rllib/policy/__init__.py b/rllib/policy/__init__.py
index 0f172dcd5..348fe187d 100644
--- a/rllib/policy/__init__.py
+++ b/rllib/policy/__init__.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.policy.policy import Policy
 from ray.rllib.policy.torch_policy import TorchPolicy
 from ray.rllib.policy.tf_policy import TFPolicy
diff --git a/rllib/policy/dynamic_tf_policy.py b/rllib/policy/dynamic_tf_policy.py
index 3a98e08f1..0398145e3 100644
--- a/rllib/policy/dynamic_tf_policy.py
+++ b/rllib/policy/dynamic_tf_policy.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Graph mode TF policy built using build_tf_policy()."""
 
 from collections import OrderedDict
diff --git a/rllib/policy/eager_tf_policy.py b/rllib/policy/eager_tf_policy.py
index 461dde7e8..f1ecb5b85 100644
--- a/rllib/policy/eager_tf_policy.py
+++ b/rllib/policy/eager_tf_policy.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """Eager mode TF policy built using build_tf_policy().
 
 It supports both traced and non-traced eager execution modes."""
diff --git a/rllib/policy/policy.py b/rllib/policy/policy.py
index 0593d5c6a..954a0366c 100644
--- a/rllib/policy/policy.py
+++ b/rllib/policy/policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from collections import namedtuple
 import numpy as np
 import gym
diff --git a/rllib/policy/rnn_sequencing.py b/rllib/policy/rnn_sequencing.py
index 1ccaeaf7c..6f4c97c93 100644
--- a/rllib/policy/rnn_sequencing.py
+++ b/rllib/policy/rnn_sequencing.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 """RNN utils for RLlib.
 
 The main trick here is that we add the time dimension at the last moment.
diff --git a/rllib/policy/sample_batch.py b/rllib/policy/sample_batch.py
index 8e177e42d..bb0c0ccc5 100644
--- a/rllib/policy/sample_batch.py
+++ b/rllib/policy/sample_batch.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import six
 import collections
 import numpy as np
diff --git a/rllib/policy/tf_policy.py b/rllib/policy/tf_policy.py
index e8c654e4c..7568fe433 100644
--- a/rllib/policy/tf_policy.py
+++ b/rllib/policy/tf_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import errno
 import logging
 import os
diff --git a/rllib/policy/tf_policy_template.py b/rllib/policy/tf_policy_template.py
index c95fdcbf5..c7730f09e 100644
--- a/rllib/policy/tf_policy_template.py
+++ b/rllib/policy/tf_policy_template.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.policy.dynamic_tf_policy import DynamicTFPolicy
 from ray.rllib.policy import eager_tf_policy
 from ray.rllib.policy.policy import Policy, LEARNER_STATS_KEY
diff --git a/rllib/policy/torch_policy.py b/rllib/policy/torch_policy.py
index 8278d7d28..5bde6b915 100644
--- a/rllib/policy/torch_policy.py
+++ b/rllib/policy/torch_policy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 try:
diff --git a/rllib/policy/torch_policy_template.py b/rllib/policy/torch_policy_template.py
index b4e978e0b..ef49f53e2 100644
--- a/rllib/policy/torch_policy_template.py
+++ b/rllib/policy/torch_policy_template.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.policy.policy import Policy
 from ray.rllib.policy.torch_policy import TorchPolicy
 from ray.rllib.models.catalog import ModelCatalog
diff --git a/rllib/rollout.py b/rllib/rollout.py
index 168a5fde0..03f78d873 100755
--- a/rllib/rollout.py
+++ b/rllib/rollout.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import collections
 import json
diff --git a/rllib/scripts.py b/rllib/scripts.py
index 88d5d5629..cf077acb3 100644
--- a/rllib/scripts.py
+++ b/rllib/scripts.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 
 from ray.rllib import train
diff --git a/rllib/tests/agents/__init__.py b/rllib/tests/agents/__init__.py
deleted file mode 100644
index 878841c18..000000000
--- a/rllib/tests/agents/__init__.py
+++ /dev/null
@@ -1,3 +0,0 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
diff --git a/rllib/tests/agents/functionality/__init__.py b/rllib/tests/agents/functionality/__init__.py
deleted file mode 100644
index 878841c18..000000000
--- a/rllib/tests/agents/functionality/__init__.py
+++ /dev/null
@@ -1,3 +0,0 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
diff --git a/rllib/tests/mock_worker.py b/rllib/tests/mock_worker.py
index 9f34e3b7e..f32b398a6 100644
--- a/rllib/tests/mock_worker.py
+++ b/rllib/tests/mock_worker.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 from ray.rllib.evaluation import SampleBatch
 
diff --git a/rllib/tests/multiagent_pendulum.py b/rllib/tests/multiagent_pendulum.py
index 6317df1c6..36adc505b 100644
--- a/rllib/tests/multiagent_pendulum.py
+++ b/rllib/tests/multiagent_pendulum.py
@@ -1,9 +1,5 @@
 """Integration test: (1) pendulum works, (2) single-agent multi-agent works."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.rllib.tests.test_multi_agent_env import make_multiagent
 from ray.tune import run_experiments
diff --git a/rllib/tests/test_avail_actions_qmix.py b/rllib/tests/test_avail_actions_qmix.py
index f38cffa5e..f43c1e6a7 100644
--- a/rllib/tests/test_avail_actions_qmix.py
+++ b/rllib/tests/test_avail_actions_qmix.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 from gym.spaces import Tuple, Discrete, Dict, Box
 
diff --git a/rllib/tests/test_checkpoint_restore.py b/rllib/tests/test_checkpoint_restore.py
index 7d00e5423..2f35fdfe7 100644
--- a/rllib/tests/test_checkpoint_restore.py
+++ b/rllib/tests/test_checkpoint_restore.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import shutil
 import gym
diff --git a/rllib/tests/test_dependency.py b/rllib/tests/test_dependency.py
index 2df0b4b95..fcb844644 100644
--- a/rllib/tests/test_dependency.py
+++ b/rllib/tests/test_dependency.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import os
 import sys
 
diff --git a/rllib/tests/test_env_with_subprocess.py b/rllib/tests/test_env_with_subprocess.py
index 1a760ff7e..3daacb438 100644
--- a/rllib/tests/test_env_with_subprocess.py
+++ b/rllib/tests/test_env_with_subprocess.py
@@ -1,9 +1,5 @@
 """Tests that envs clean up after themselves on agent exit."""
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from gym.spaces import Discrete
 import atexit
 import gym
diff --git a/rllib/tests/test_evaluators.py b/rllib/tests/test_evaluators.py
index 4af4d02a4..246bb94d7 100644
--- a/rllib/tests/test_evaluators.py
+++ b/rllib/tests/test_evaluators.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 
 import ray
diff --git a/rllib/tests/test_external_env.py b/rllib/tests/test_external_env.py
index 24281e757..c9aff809c 100644
--- a/rllib/tests/test_external_env.py
+++ b/rllib/tests/test_external_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import numpy as np
 import random
diff --git a/rllib/tests/test_external_multi_agent_env.py b/rllib/tests/test_external_multi_agent_env.py
index 91a087c6b..65e7b9bdf 100644
--- a/rllib/tests/test_external_multi_agent_env.py
+++ b/rllib/tests/test_external_multi_agent_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import numpy as np
 import random
diff --git a/rllib/tests/test_filters.py b/rllib/tests/test_filters.py
index 9c4110a90..ba70b7afc 100644
--- a/rllib/tests/test_filters.py
+++ b/rllib/tests/test_filters.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 import numpy as np
 
diff --git a/rllib/tests/test_ignore_worker_failure.py b/rllib/tests/test_ignore_worker_failure.py
index 3a9970397..12c5341da 100644
--- a/rllib/tests/test_ignore_worker_failure.py
+++ b/rllib/tests/test_ignore_worker_failure.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import unittest
 
diff --git a/rllib/tests/test_io.py b/rllib/tests/test_io.py
index e189dcce3..c8ff0101d 100644
--- a/rllib/tests/test_io.py
+++ b/rllib/tests/test_io.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import glob
 import gym
 import json
diff --git a/rllib/tests/test_legacy.py b/rllib/tests/test_legacy.py
index ae8285881..5cbb428c4 100644
--- a/rllib/tests/test_legacy.py
+++ b/rllib/tests/test_legacy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.agents.ppo import PPOAgent
 from ray import tune
 import ray
diff --git a/rllib/tests/test_local.py b/rllib/tests/test_local.py
index 67f7bc7d5..c3341beaf 100644
--- a/rllib/tests/test_local.py
+++ b/rllib/tests/test_local.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 
 from ray.rllib.agents.ppo import PPOTrainer, DEFAULT_CONFIG
diff --git a/rllib/tests/test_lstm.py b/rllib/tests/test_lstm.py
index 15decb3fe..46b2ff6b7 100644
--- a/rllib/tests/test_lstm.py
+++ b/rllib/tests/test_lstm.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import numpy as np
 import pickle
diff --git a/rllib/tests/test_multi_agent_env.py b/rllib/tests/test_multi_agent_env.py
index 17e333f07..835560417 100644
--- a/rllib/tests/test_multi_agent_env.py
+++ b/rllib/tests/test_multi_agent_env.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import random
 import unittest
diff --git a/rllib/tests/test_nested_spaces.py b/rllib/tests/test_nested_spaces.py
index 1127565dd..24f17d911 100644
--- a/rllib/tests/test_nested_spaces.py
+++ b/rllib/tests/test_nested_spaces.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import pickle
 
 from gym import spaces
diff --git a/rllib/tests/test_optimizers.py b/rllib/tests/test_optimizers.py
index a5df9b3e6..870a352d3 100644
--- a/rllib/tests/test_optimizers.py
+++ b/rllib/tests/test_optimizers.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import numpy as np
 import time
diff --git a/rllib/tests/test_perf.py b/rllib/tests/test_perf.py
index 6ed02a0ff..f86d3bd85 100644
--- a/rllib/tests/test_perf.py
+++ b/rllib/tests/test_perf.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import time
 import unittest
diff --git a/rllib/tests/test_reproducibility.py b/rllib/tests/test_reproducibility.py
index 1cc034759..b5ca13f7b 100644
--- a/rllib/tests/test_reproducibility.py
+++ b/rllib/tests/test_reproducibility.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import unittest
 
 import ray
diff --git a/rllib/tests/test_rollout_worker.py b/rllib/tests/test_rollout_worker.py
index 45b2fa015..345c33a6a 100644
--- a/rllib/tests/test_rollout_worker.py
+++ b/rllib/tests/test_rollout_worker.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import gym
 import numpy as np
 import random
diff --git a/rllib/train.py b/rllib/train.py
index a632b85f1..0a7df5c6f 100755
--- a/rllib/train.py
+++ b/rllib/train.py
@@ -1,9 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import yaml
 
diff --git a/rllib/utils/actors.py b/rllib/utils/actors.py
index 92c7799ac..676019110 100644
--- a/rllib/utils/actors.py
+++ b/rllib/utils/actors.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import os
 import ray
diff --git a/rllib/utils/annotations.py b/rllib/utils/annotations.py
index 0dcd960a4..bd0111e69 100644
--- a/rllib/utils/annotations.py
+++ b/rllib/utils/annotations.py
@@ -1,8 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-
 def override(cls):
     """Annotation for documenting method overrides.
 
diff --git a/rllib/utils/compression.py b/rllib/utils/compression.py
index 20a19ead6..e979ef902 100644
--- a/rllib/utils/compression.py
+++ b/rllib/utils/compression.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils.annotations import DeveloperAPI
 
 import logging
diff --git a/rllib/utils/debug.py b/rllib/utils/debug.py
index c38b466b4..ef4aa37b2 100644
--- a/rllib/utils/debug.py
+++ b/rllib/utils/debug.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import pprint
 import time
diff --git a/rllib/utils/deprecation.py b/rllib/utils/deprecation.py
index 707eebcdb..fd6628925 100644
--- a/rllib/utils/deprecation.py
+++ b/rllib/utils/deprecation.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 
 
diff --git a/rllib/utils/error.py b/rllib/utils/error.py
index 082c84c9e..462058f05 100644
--- a/rllib/utils/error.py
+++ b/rllib/utils/error.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils.annotations import PublicAPI
 
 
diff --git a/rllib/utils/explained_variance.py b/rllib/utils/explained_variance.py
index 907a00b6b..6db6c0d9b 100644
--- a/rllib/utils/explained_variance.py
+++ b/rllib/utils/explained_variance.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils import try_import_tf, try_import_torch
 
 tf = try_import_tf()
diff --git a/rllib/utils/filter.py b/rllib/utils/filter.py
index f1b5ee081..46f829017 100644
--- a/rllib/utils/filter.py
+++ b/rllib/utils/filter.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import numpy as np
 import threading
diff --git a/rllib/utils/filter_manager.py b/rllib/utils/filter_manager.py
index 1c7cc81c4..18efe2edc 100644
--- a/rllib/utils/filter_manager.py
+++ b/rllib/utils/filter_manager.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import ray
 from ray.rllib.utils.annotations import DeveloperAPI
 from ray.rllib.utils.memory import ray_get_and_free
diff --git a/rllib/utils/framework.py b/rllib/utils/framework.py
index 23cab9fdf..1bde1df01 100644
--- a/rllib/utils/framework.py
+++ b/rllib/utils/framework.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import os
 
diff --git a/rllib/utils/memory.py b/rllib/utils/memory.py
index 78bab8380..0c04bb15d 100644
--- a/rllib/utils/memory.py
+++ b/rllib/utils/memory.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import time
 
diff --git a/rllib/utils/numpy.py b/rllib/utils/numpy.py
index 7b0040dbc..625b31e80 100644
--- a/rllib/utils/numpy.py
+++ b/rllib/utils/numpy.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 
diff --git a/rllib/utils/policy_client.py b/rllib/utils/policy_client.py
index 017f4fb39..6071c258c 100644
--- a/rllib/utils/policy_client.py
+++ b/rllib/utils/policy_client.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import pickle
 
diff --git a/rllib/utils/policy_server.py b/rllib/utils/policy_server.py
index fe359ca8d..be69480e3 100644
--- a/rllib/utils/policy_server.py
+++ b/rllib/utils/policy_server.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import pickle
 import traceback
 
diff --git a/rllib/utils/schedules.py b/rllib/utils/schedules.py
index 149402a2e..36953c2c6 100644
--- a/rllib/utils/schedules.py
+++ b/rllib/utils/schedules.py
@@ -7,9 +7,6 @@ time throughout the execution of the algorithm, such as:
 Each schedule has a function `value(t)` which returns the current value
 of the parameter given the timestep t of the optimization procedure.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
 
 
 class Schedule:
diff --git a/rllib/utils/seed.py b/rllib/utils/seed.py
index 3675fd119..513c34fc7 100644
--- a/rllib/utils/seed.py
+++ b/rllib/utils/seed.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import random
 from ray.rllib.utils import try_import_tf
diff --git a/rllib/utils/test_utils.py b/rllib/utils/test_utils.py
index 04078702c..8759296ce 100644
--- a/rllib/utils/test_utils.py
+++ b/rllib/utils/test_utils.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 from ray.rllib.utils.framework import try_import_tf
diff --git a/rllib/utils/tf_ops.py b/rllib/utils/tf_ops.py
index 8efdd9f1a..f94f54ce6 100644
--- a/rllib/utils/tf_ops.py
+++ b/rllib/utils/tf_ops.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils import try_import_tf
 
 tf = try_import_tf()
diff --git a/rllib/utils/tf_run_builder.py b/rllib/utils/tf_run_builder.py
index 5521f364e..94128c7a3 100644
--- a/rllib/utils/tf_run_builder.py
+++ b/rllib/utils/tf_run_builder.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import os
 import time
diff --git a/rllib/utils/timer.py b/rllib/utils/timer.py
index e4be372b6..eca95b71f 100644
--- a/rllib/utils/timer.py
+++ b/rllib/utils/timer.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 import time
 
diff --git a/rllib/utils/torch_ops.py b/rllib/utils/torch_ops.py
index 91a952f90..58edd9f91 100644
--- a/rllib/utils/torch_ops.py
+++ b/rllib/utils/torch_ops.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.rllib.utils.framework import try_import_torch
 
 torch, _ = try_import_torch()
diff --git a/rllib/utils/tracking_dict.py b/rllib/utils/tracking_dict.py
index 9b64925dc..0a8d8a81e 100644
--- a/rllib/utils/tracking_dict.py
+++ b/rllib/utils/tracking_dict.py
@@ -1,8 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-
 class UsageTrackingDict(dict):
     """Dict that tracks which keys have been accessed.
 
diff --git a/rllib/utils/window_stat.py b/rllib/utils/window_stat.py
index a6277540b..4c3221070 100644
--- a/rllib/utils/window_stat.py
+++ b/rllib/utils/window_stat.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import numpy as np
 
 
diff --git a/streaming/python/communication.py b/streaming/python/communication.py
index 4aa2b32fe..576305186 100644
--- a/streaming/python/communication.py
+++ b/streaming/python/communication.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import hashlib
 import logging
 import pickle
diff --git a/streaming/python/examples/key_selectors.py b/streaming/python/examples/key_selectors.py
index 6533d49b0..2c8e784ed 100644
--- a/streaming/python/examples/key_selectors.py
+++ b/streaming/python/examples/key_selectors.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import logging
 import time
diff --git a/streaming/python/examples/simple.py b/streaming/python/examples/simple.py
index 0e12317ad..43264abb4 100644
--- a/streaming/python/examples/simple.py
+++ b/streaming/python/examples/simple.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import logging
 import time
diff --git a/streaming/python/examples/wordcount.py b/streaming/python/examples/wordcount.py
index acf363f77..d9ce4cd54 100644
--- a/streaming/python/examples/wordcount.py
+++ b/streaming/python/examples/wordcount.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import argparse
 import logging
 import time
diff --git a/streaming/python/jobworker.py b/streaming/python/jobworker.py
index b75e43420..ed97f6735 100644
--- a/streaming/python/jobworker.py
+++ b/streaming/python/jobworker.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import pickle
 import threading
diff --git a/streaming/python/operator.py b/streaming/python/operator.py
index ad2594f06..036f00d4a 100644
--- a/streaming/python/operator.py
+++ b/streaming/python/operator.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import enum
 import logging
 
diff --git a/streaming/python/processor.py b/streaming/python/processor.py
index 4ffcf2cab..96da54245 100644
--- a/streaming/python/processor.py
+++ b/streaming/python/processor.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import sys
 import time
diff --git a/streaming/python/streaming.py b/streaming/python/streaming.py
index 32d2d1a02..03a11608a 100644
--- a/streaming/python/streaming.py
+++ b/streaming/python/streaming.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import logging
 import pickle
 import sys
diff --git a/streaming/python/tests/test_logical_graph.py b/streaming/python/tests/test_logical_graph.py
index 863cfc6da..2e13723df 100644
--- a/streaming/python/tests/test_logical_graph.py
+++ b/streaming/python/tests/test_logical_graph.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 from ray.streaming.streaming import Environment, ExecutionGraph
 from ray.streaming.operator import OpType, PStrategy