Remove six and cloudpickle from setup.py. (#7694)

python/ray/actor.py

@@ -1,7 +1,6 @@
 import copy
 import inspect
 import logging
-import six
 import weakref
 
 from abc import ABCMeta, abstractmethod
@@ -963,7 +962,7 @@ Checkpoint = namedtuple(
 """A namedtuple that represents a checkpoint."""
 
 
-class Checkpointable(six.with_metaclass(ABCMeta, object)):
+class Checkpointable(metaclass=ABCMeta):
     """An interface that indicates an actor can be checkpointed."""
 
     @abstractmethod

python/ray/tests/test_advanced.py

@@ -3,7 +3,6 @@ from concurrent.futures import ThreadPoolExecutor
 import json
 import logging
 import random
-import six
 import sys
 import threading
 import time
@@ -365,10 +364,6 @@ def test_illegal_api_calls(ray_start_regular):
         ray.get(3)
 
 
-# TODO(hchen): This test currently doesn't work in Python 2. This is likely
-# because plasma client isn't thread-safe. This needs to be fixed from the
-# Arrow side. See #4107 for relevant discussions.
-@pytest.mark.skipif(six.PY2, reason="Doesn't work in Python 2.")
 def test_multithreading(ray_start_2_cpus):
     # This test requires at least 2 CPUs to finish since the worker does not
     # release resources when joining the threads.

python/ray/tune/examples/durable_trainable_example.py

@@ -8,7 +8,7 @@ from ray import tune
 from ray.tune import DurableTrainable
 from ray.tune.sync_client import get_sync_client
 
-import cloudpickle
+from ray import cloudpickle
 
 logger = logging.getLogger(__name__)
 

python/ray/tune/experiment.py

@@ -1,7 +1,6 @@
 import copy
 import logging
 import os
-import six
 
 from ray.tune.error import TuneError
 from ray.tune.registry import register_trainable, get_trainable_cls
@@ -189,7 +188,7 @@ class Experiment:
             A string representing the trainable identifier.
         """
 
-        if isinstance(run_object, six.string_types):
+        if isinstance(run_object, str):
             return run_object
         elif isinstance(run_object, sample_from):
             logger.warning("Not registering trainable. Resolving as variant.")

python/ray/tune/tune.py

@@ -1,5 +1,4 @@
 import logging
-import six
 
 from ray.tune.error import TuneError
 from ray.tune.experiment import convert_to_experiment_list, Experiment
@@ -41,7 +40,7 @@ def _make_scheduler(args):
 
 
 def _check_default_resources_override(run_identifier):
-    if not isinstance(run_identifier, six.string_types):
+    if not isinstance(run_identifier, str):
         # If obscure dtype, assume it is overriden.
         return True
     trainable_cls = get_trainable_cls(run_identifier)

python/ray/utils.py

@@ -5,7 +5,6 @@ import inspect
 import logging
 import numpy as np
 import os
-import six
 import subprocess
 import sys
 import tempfile
@@ -223,32 +222,14 @@ def decode(byte_str, allow_none=False):
 def ensure_str(s, encoding="utf-8", errors="strict"):
     """Coerce *s* to `str`.
 
-    To keep six with lower version, see Issue 4169, we copy this function
-    from six == 1.12.0.
-
-    TODO(yuhguo): remove this function when six >= 1.12.0.
-
-    For Python 2:
-      - `unicode` -> encoded to `str`
-      - `str` -> `str`
-
-    For Python 3:
       - `str` -> `str`
       - `bytes` -> decoded to `str`
     """
-    if six.PY3:
-        text_type = str
-        binary_type = bytes
+    if isinstance(s, str):
+        return s
     else:
-        text_type = unicode  # noqa: F821
-        binary_type = str
-    if not isinstance(s, (text_type, binary_type)):
-        raise TypeError("not expecting type '%s'" % type(s))
-    if six.PY2 and isinstance(s, text_type):
-        s = s.encode(encoding, errors)
-    elif six.PY3 and isinstance(s, binary_type):
-        s = s.decode(encoding, errors)
-    return s
+        assert isinstance(s, bytes)
+        return s.decode(encoding, errors)
 
 
 def binary_to_object_id(binary_object_id):

python/setup.py

@@ -171,24 +171,9 @@ def find_version(*filepath):
 
 
 requires = [
-    "numpy >= 1.16",
-    "filelock",
-    "jsonschema",
-    "click",
-    "colorama",
-    "packaging",
-    "pyyaml",
-    "redis>=3.3.2",
-    # NOTE: Don't upgrade the version of six! Doing so causes installation
-    # problems. See https://github.com/ray-project/ray/issues/4169.
-    "six >= 1.0.0",
-    "faulthandler;python_version<'3.3'",
-    "protobuf >= 3.8.0",
-    "cloudpickle",
-    "py-spy >= 0.2.0",
-    "aiohttp",
-    "google",
-    "grpcio"
+    "numpy >= 1.16", "filelock", "jsonschema", "click", "colorama",
+    "packaging", "pyyaml", "redis >= 3.3.2", "protobuf >= 3.8.0",
+    "py-spy >= 0.2.0", "aiohttp", "google", "grpcio"
 ]
 
 setup(