Merge commit for internal changes.

23 files changed, 46 insertions, 189 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7b41a67..3c36751 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,9 +6,14 @@ The format is based on [Keep a Changelog](https://keepachangelog.com).
 
 ## Unreleased
 
+Nothing notable unreleased.
+
+## 1.1.0 (2022-06-01)
+
 *   `Flag` instances now raise an error if used in a bool context. This prevents
     the occasional mistake of testing an instance for truthiness rather than
     testing `flag.value`.
+*   `absl-py` no longer depends on `six`.
 
 ## 1.0.0 (2021-11-09)
 
diff --git a/WORKSPACE b/WORKSPACE
index 1370aae..a964e21 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -12,16 +12,3 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 workspace(name = "io_abseil_py")
-
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-
-http_archive(
-    name = "six_archive",
-    build_file = "@//third_party:six.BUILD",
-    sha256 = "105f8d68616f8248e24bf0e9372ef04d3cc10104f1980f54d57b2ce73a5ad56a",
-    strip_prefix = "six-1.10.0",
-    urls = [
-        "http://mirror.bazel.build/pypi.python.org/packages/source/s/six/six-1.10.0.tar.gz",
-        "https://pypi.python.org/packages/source/s/six/six-1.10.0.tar.gz",
-    ],
-)
diff --git a/absl/BUILD b/absl/BUILD
index 496b0e3..4e747ea 100644
--- a/absl/BUILD
+++ b/absl/BUILD
@@ -22,13 +22,6 @@ py_library(
 )
 
 py_library(
-    name = "_collections_abc",
-    srcs = ["_collections_abc.py"],
-    visibility = [":__subpackages__"],
-    deps = ["@six_archive//:six"],
-)
-
-py_library(
     name = "tests/app_test_helper",
     testonly = 1,
     srcs = ["tests/app_test_helper.py"],
diff --git a/absl/_collections_abc.py b/absl/_collections_abc.py
deleted file mode 100644
index 1d06f05..0000000
--- a/absl/_collections_abc.py
+++ /dev/null
@@ -1,28 +0,0 @@
-# Copyright 2019 The Abseil Authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-"""Python 2/3 compatibility module for collections.abc."""
-
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-import six
-
-# pylint: disable=g-importing-member
-# pylint: disable=unused-import
-if six.PY3:
-  from collections import abc
-else:
-  import collections as abc
diff --git a/absl/flags/BUILD b/absl/flags/BUILD
index c180599..33a7b07 100644
--- a/absl/flags/BUILD
+++ b/absl/flags/BUILD
@@ -13,7 +13,6 @@ py_library(
         ":_flagvalues",
         ":_helpers",
         ":_validators",
-        "@six_archive//:six",
     ],
 )
 
@@ -31,7 +30,6 @@ py_library(
     srcs_version = "PY2AND3",
     deps = [
         ":_helpers",
-        "@six_archive//:six",
     ],
 )
 
@@ -66,8 +64,6 @@ py_library(
         ":_argument_parser",
         ":_exceptions",
         ":_helpers",
-        "//absl:_collections_abc",
-        "@six_archive//:six",
     ],
 )
 
@@ -80,7 +76,6 @@ py_library(
         ":_flag",
         ":_helpers",
         ":_validators_classes",
-        "@six_archive//:six",
     ],
 )
 
@@ -88,7 +83,6 @@ py_library(
     name = "_helpers",
     srcs = ["_helpers.py"],
     srcs_version = "PY2AND3",
-    deps = ["@six_archive//:six"],
 )
 
 py_library(
diff --git a/absl/flags/__init__.py b/absl/flags/__init__.py
index 99501bb..e6014a6 100644
--- a/absl/flags/__init__.py
+++ b/absl/flags/__init__.py
@@ -25,10 +25,6 @@ The specific function used determines how the flag is parsed, checked,
 and optionally type-converted, when it's seen on the command line.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import getopt
 import os
 import re
@@ -43,7 +39,6 @@ from absl.flags import _flag
 from absl.flags import _flagvalues
 from absl.flags import _helpers
 from absl.flags import _validators
-import six
 
 # Initialize the FLAGS_MODULE as early as possible.
 # It's only used by adopt_module_key_flags to take SPECIAL_FLAGS into account.
diff --git a/absl/flags/_argument_parser.py b/absl/flags/_argument_parser.py
index 4f6bd69..9c6c8c6 100644
--- a/absl/flags/_argument_parser.py
+++ b/absl/flags/_argument_parser.py
@@ -18,22 +18,17 @@ Do NOT import this module directly. Import the flags package and use the
 aliases defined at the package level instead.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import collections
 import csv
 import io
 import string
 
 from absl.flags import _helpers
-import six
 
 
 def _is_integer_type(instance):
   """Returns True if instance is an integer, and not a bool."""
-  return (isinstance(instance, six.integer_types) and
+  return (isinstance(instance, int) and
           not isinstance(instance, bool))
 
 
@@ -95,7 +90,7 @@ class _ArgumentParserCache(type):
 #   inherit from `ArgumentParser` and not `ArgumentParser[SomeType]`.
 #   The corresponding DEFINE_someType method (the public API) can be annotated
 #   to return FlagHolder[SomeType].
-class ArgumentParser(six.with_metaclass(_ArgumentParserCache, object)):
+class ArgumentParser(metaclass=_ArgumentParserCache):
   """Base class used to parse and convert arguments.
 
   The parse() method checks to make sure that the string argument is a
@@ -128,7 +123,7 @@ class ArgumentParser(six.with_metaclass(_ArgumentParserCache, object)):
     Returns:
       The parsed value in native type.
     """
-    if not isinstance(argument, six.string_types):
+    if not isinstance(argument, str):
       raise TypeError('flag value must be a string, found "{}"'.format(
           type(argument)))
     return argument
@@ -228,7 +223,7 @@ class FloatParser(NumericParser):
   def convert(self, argument):
     """Returns the float value of argument."""
     if (_is_integer_type(argument) or isinstance(argument, float) or
-        isinstance(argument, six.string_types)):
+        isinstance(argument, str)):
       return float(argument)
     else:
       raise TypeError(
@@ -274,7 +269,7 @@ class IntegerParser(NumericParser):
     """Returns the int value of argument."""
     if _is_integer_type(argument):
       return argument
-    elif isinstance(argument, six.string_types):
+    elif isinstance(argument, str):
       base = 10
       if len(argument) > 2 and argument[0] == '0':
         if argument[1] == 'o':
@@ -296,14 +291,14 @@ class BooleanParser(ArgumentParser):
 
   def parse(self, argument):
     """See base class."""
-    if isinstance(argument, six.string_types):
+    if isinstance(argument, str):
       if argument.lower() in ('true', 't', '1'):
         return True
       elif argument.lower() in ('false', 'f', '0'):
         return False
       else:
         raise ValueError('Non-boolean argument to boolean flag', argument)
-    elif isinstance(argument, six.integer_types):
+    elif isinstance(argument, int):
       # Only allow bool or integer 0, 1.
       # Note that float 1.0 == True, 0.0 == False.
       bool_value = bool(argument)
@@ -433,7 +428,7 @@ class EnumClassParser(ArgumentParser):
     """
     if isinstance(argument, self.enum_class):
       return argument
-    elif not isinstance(argument, six.string_types):
+    elif not isinstance(argument, str):
       raise ValueError(
           '{} is not an enum member or a name of a member in {}'.format(
               argument, self.enum_class))
@@ -496,18 +491,10 @@ class CsvListSerializer(ArgumentSerializer):
 
   def serialize(self, value):
     """Serializes a list as a CSV string or unicode."""
-    if six.PY2:
-      # In Python2 csv.writer doesn't accept unicode, so we convert to UTF-8.
-      output = io.BytesIO()
-      writer = csv.writer(output, delimiter=self.list_sep)
-      writer.writerow([unicode(x).encode('utf-8') for x in value])  # pylint: disable=undefined-variable
-      serialized_value = output.getvalue().decode('utf-8').strip()
-    else:
-      # In Python3 csv.writer expects a text stream.
-      output = io.StringIO()
-      writer = csv.writer(output, delimiter=self.list_sep)
-      writer.writerow([str(x) for x in value])
-      serialized_value = output.getvalue().strip()
+    output = io.StringIO()
+    writer = csv.writer(output, delimiter=self.list_sep)
+    writer.writerow([str(x) for x in value])
+    serialized_value = output.getvalue().strip()
 
     # We need the returned value to be pure ascii or Unicodes so that
     # when the xml help is generated they are usefully encodable.
diff --git a/absl/flags/_flag.py b/absl/flags/_flag.py
index a1c53ff..d7ad944 100644
--- a/absl/flags/_flag.py
+++ b/absl/flags/_flag.py
@@ -18,18 +18,13 @@ Do NOT import this module directly. Import the flags package and use the
 aliases defined at the package level instead.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
+from collections import abc
 import copy
 import functools
 
-from absl._collections_abc import abc
 from absl.flags import _argument_parser
 from absl.flags import _exceptions
 from absl.flags import _helpers
-import six
 
 
 @functools.total_ordering
@@ -411,7 +406,7 @@ class MultiFlag(Flag):
 
   def _parse(self, arguments):
     if (isinstance(arguments, abc.Iterable) and
-        not isinstance(arguments, six.string_types)):
+        not isinstance(arguments, str)):
       arguments = list(arguments)
 
     if not isinstance(arguments, list):
diff --git a/absl/flags/_flag.pyi b/absl/flags/_flag.pyi
index f28bbf3..9b4a3d3 100644
--- a/absl/flags/_flag.pyi
+++ b/absl/flags/_flag.pyi
@@ -17,10 +17,8 @@
 import copy
 import functools
 
-from absl._collections_abc import abc
 from absl.flags import _argument_parser
 import enum
-import six
 
 from typing import Text, TypeVar, Generic, Iterable, Type, List, Optional, Any, Union, Sequence
 
diff --git a/absl/flags/_flagvalues.py b/absl/flags/_flagvalues.py
index c9be720..1b54fb3 100644
--- a/absl/flags/_flagvalues.py
+++ b/absl/flags/_flagvalues.py
@@ -17,36 +17,26 @@ Do NOT import this module directly. Import the flags package and use the
 aliases defined at the package level instead.
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
 import copy
 import itertools
 import logging
 import os
 import sys
+from typing import Generic, TypeVar
 from xml.dom import minidom
 
 from absl.flags import _exceptions
 from absl.flags import _flag
 from absl.flags import _helpers
 from absl.flags import _validators_classes
-import six
-
-# pylint: disable=unused-import
-try:
-  import typing
-  from typing import Text, Optional
-except ImportError:
-  typing = None
-# pylint: enable=unused-import
 
 # Add flagvalues module to disclaimed module ids.
 _helpers.disclaim_module_ids.add(id(sys.modules[__name__]))
 
+_T = TypeVar('_T')
+
 
-class FlagValues(object):
+class FlagValues:
   """Registry of 'Flag' objects.
 
   A 'FlagValues' can then scan command line arguments, passing flag
@@ -247,7 +237,7 @@ class FlagValues(object):
     for flags_by_module_dict in (self.flags_by_module_dict(),
                                  self.flags_by_module_id_dict(),
                                  self.key_flags_by_module_dict()):
-      for flags_in_module in six.itervalues(flags_by_module_dict):
+      for flags_in_module in flags_by_module_dict.values():
         # While (as opposed to if) takes care of multiple occurrences of a
         # flag in the list for the same module.
         while flag_obj in flags_in_module:
@@ -313,7 +303,7 @@ class FlagValues(object):
     registered_flag = self._flags().get(flagname)
     if registered_flag is None:
       return default
-    for module, flags in six.iteritems(self.flags_by_module_dict()):
+    for module, flags in self.flags_by_module_dict().items():
       for flag in flags:
         # It must compare the flag with the one in _flags. This is because a
         # flag might be overridden only for its long name (or short name),
@@ -338,7 +328,7 @@ class FlagValues(object):
     registered_flag = self._flags().get(flagname)
     if registered_flag is None:
       return default
-    for module_id, flags in six.iteritems(self.flags_by_module_id_dict()):
+    for module_id, flags in self.flags_by_module_id_dict().items():
       for flag in flags:
         # It must compare the flag with the one in _flags. This is because a
         # flag might be overridden only for its long name (or short name),
@@ -389,7 +379,7 @@ class FlagValues(object):
     Args:
       flag_values: FlagValues, the FlagValues instance from which to copy flags.
     """
-    for flag_name, flag in six.iteritems(flag_values._flags()):  # pylint: disable=protected-access
+    for flag_name, flag in flag_values._flags().items():  # pylint: disable=protected-access
       # Each flags with short_name appears here twice (once under its
       # normal name, and again with its short name).  To prevent
       # problems (DuplicateFlagError) with double flag registration, we
@@ -485,18 +475,8 @@ class FlagValues(object):
     if self.__dict__['__flags_parsed'] or fl[name].present:
       return fl[name].value
     else:
-      error_message = ('Trying to access flag --%s before flags were parsed.' %
-                       name)
-      if six.PY2:
-        # In Python 2, hasattr returns False if getattr raises any exception.
-        # That means if someone calls hasattr(FLAGS, 'flag'), it returns False
-        # instead of raises UnparsedFlagAccessError even if --flag is already
-        # defined. To make the error more visible, the best we can do is to
-        # log an error message before raising the exception.
-        # Don't log a full stacktrace here since that makes other callers
-        # get too much noise.
-        logging.error(error_message)
-      raise _exceptions.UnparsedFlagAccessError(error_message)
+      raise _exceptions.UnparsedFlagAccessError(
+          'Trying to access flag --%s before flags were parsed.' % name)
 
   def __setattr__(self, name, value):
     """Sets the 'value' attribute of the flag --name."""
@@ -507,7 +487,7 @@ class FlagValues(object):
     """Sets multiple flag values together, triggers validators afterwards."""
     fl = self._flags()
     known_flags = set()
-    for name, value in six.iteritems(attributes):
+    for name, value in attributes.items():
       if name in self.__dict__['__hiddenflags']:
         raise AttributeError(name)
       if name in fl:
@@ -528,7 +508,7 @@ class FlagValues(object):
           validator.
     """
     all_validators = set()
-    for flag in six.itervalues(self._flags()):
+    for flag in self._flags().values():
       all_validators.update(flag.validators)
     self._assert_validators(all_validators)
 
@@ -858,7 +838,7 @@ class FlagValues(object):
 
   def flag_values_dict(self):
     """Returns a dictionary that maps flag names to flag values."""
-    return {name: flag.value for name, flag in six.iteritems(self._flags())}
+    return {name: flag.value for name, flag in self._flags().items()}
 
   def __str__(self):
     """Returns a help string for all known flags."""
@@ -887,11 +867,10 @@ class FlagValues(object):
     else:
       output_lines = []
       # Just print one long list of flags.
-      values = six.itervalues(self._flags())
+      values = self._flags().values()
       if include_special_flags:
-        values = itertools.chain(values,
-                                 six.itervalues(
-                                     _helpers.SPECIAL_FLAGS._flags()))  # pylint: disable=protected-access
+        values = itertools.chain(
+            values, _helpers.SPECIAL_FLAGS._flags().values())  # pylint: disable=protected-access
       self._render_flag_list(values, output_lines, prefix)
       return '\n'.join(output_lines)
 
@@ -912,7 +891,7 @@ class FlagValues(object):
     if include_special_flags:
       self._render_module_flags(
           'absl.flags',
-          six.itervalues(_helpers.SPECIAL_FLAGS._flags()),  # pylint: disable=protected-access
+          _helpers.SPECIAL_FLAGS._flags().values(),  # pylint: disable=protected-access
           output_lines,
           prefix)
     return '\n'.join(output_lines)
@@ -1291,11 +1270,8 @@ class FlagValues(object):
                 is_key=is_key))
 
     outfile = outfile or sys.stdout
-    if six.PY2:
-      outfile.write(doc.toprettyxml(indent='  ', encoding='utf-8'))
-    else:
-      outfile.write(
-          doc.toprettyxml(indent='  ', encoding='utf-8').decode('utf-8'))
+    outfile.write(
+        doc.toprettyxml(indent='  ', encoding='utf-8').decode('utf-8'))
     outfile.flush()
 
   def _check_method_name_conflicts(self, name, flag):
@@ -1316,14 +1292,8 @@ class FlagValues(object):
 
 FLAGS = FlagValues()
 
-if typing:
-  _T = typing.TypeVar('_T')
-  _Base = typing.Generic[_T]
-else:
-  _Base = object
-
 
-class FlagHolder(_Base):
+class FlagHolder(Generic[_T]):
   """Holds a defined flag.
 
   This facilitates a cleaner api around global state. Instead of
diff --git a/absl/flags/_flagvalues.pyi b/absl/flags/_flagvalues.pyi
index 9f1e1a5..e25c6dd 100644
--- a/absl/flags/_flagvalues.pyi
+++ b/absl/flags/_flagvalues.pyi
@@ -16,7 +16,6 @@
 
 
 from absl.flags import _flag
-import six
 
 from typing import Any, Dict, Generic, Iterable, Iterator, List, Optional, Sequence, Text, Type, TypeVar
 
diff --git a/absl/flags/_helpers.py b/absl/flags/_helpers.py
index 68b8cfc..37ae360 100644
--- a/absl/flags/_helpers.py
+++ b/absl/flags/_helpers.py
@@ -34,9 +34,6 @@ try:
 except ImportError:
   termios = None
 
-import six
-from six.moves import range  # pylint: disable=redefined-builtin
-
 
 _DEFAULT_HELP_WIDTH = 80  # Default width of help output.
 _MIN_HELP_WIDTH = 40  # Minimal "sane" width of help output. We assume that any
@@ -172,9 +169,6 @@ def create_xml_dom_element(doc, name, value):
     An instance of minidom.Element.
   """
   s = str_or_unicode(value)
-  if six.PY2 and not isinstance(s, unicode):
-    # Get a valid unicode string.
-    s = s.decode('utf-8', 'ignore')
   if isinstance(value, bool):
     # Display boolean values as the C++ flag library does: no caps.
     s = s.lower()
@@ -340,7 +334,7 @@ def flag_dict_to_args(flag_map, multi_flags=None):
   Yields:
     sequence of string suitable for a subprocess execution.
   """
-  for key, value in six.iteritems(flag_map):
+  for key, value in flag_map.items():
     if value is None:
       yield '--%s' % key
     elif isinstance(value, bool):
diff --git a/absl/logging/BUILD b/absl/logging/BUILD
index e666d7a..6c0d1bc 100644
--- a/absl/logging/BUILD
+++ b/absl/logging/BUILD
@@ -7,7 +7,6 @@ py_library(
     visibility = ["//visibility:public"],
     deps = [
         ":converter",
-        "//absl:_collections_abc",
         "//absl/flags",
     ],
 )
diff --git a/absl/logging/__init__.py b/absl/logging/__init__.py
index a475bd5..8804490 100644
--- a/absl/logging/__init__.py
+++ b/absl/logging/__init__.py
@@ -72,6 +72,7 @@ The differences in behavior are historical and unfortunate.
 """
 
 import collections
+from collections import abc
 import getpass
 import io
 import itertools
@@ -88,7 +89,6 @@ import types
 import warnings
 
 from absl import flags
-from absl._collections_abc import abc
 from absl.logging import converter
 
 try:
diff --git a/absl/testing/BUILD b/absl/testing/BUILD
index 6dbbaea..b608c8c 100644
--- a/absl/testing/BUILD
+++ b/absl/testing/BUILD
@@ -8,7 +8,6 @@ py_library(
     deps = [
         ":_pretty_print_reporter",
         ":xml_reporter",
-        "//absl:_collections_abc",
         "//absl:app",
         "//absl/flags",
         "//absl/logging",
@@ -34,7 +33,6 @@ py_library(
     visibility = ["//visibility:public"],
     deps = [
         ":absltest",
-        "//absl:_collections_abc",
     ],
 )
 
@@ -225,7 +223,6 @@ py_test(
     deps = [
         ":absltest",
         ":parameterized",
-        "//absl:_collections_abc",
     ],
 )
 
diff --git a/absl/testing/absltest.py b/absl/testing/absltest.py
index 1303fd4..cebb1ca 100644
--- a/absl/testing/absltest.py
+++ b/absl/testing/absltest.py
@@ -18,6 +18,7 @@ This module contains base classes and high-level functions for Abseil-style
 tests.
 """
 
+from collections import abc
 import contextlib
 import difflib
 import enum
@@ -55,7 +56,6 @@ except ImportError:
 from absl import app
 from absl import flags
 from absl import logging
-from absl._collections_abc import abc
 from absl.testing import _pretty_print_reporter
 from absl.testing import xml_reporter
 
diff --git a/absl/testing/parameterized.py b/absl/testing/parameterized.py
index f318b98..ec6a529 100644
--- a/absl/testing/parameterized.py
+++ b/absl/testing/parameterized.py
@@ -204,10 +204,7 @@ as [asynctest](https://github.com/Martiusweb/asynctest):
       self.assertEqual(actual, expected)
 """
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
+from collections import abc
 import functools
 import inspect
 import itertools
@@ -215,7 +212,6 @@ import re
 import types
 import unittest
 
-from absl._collections_abc import abc
 from absl.testing import absltest
 
 
diff --git a/absl/testing/tests/absltest_py3_test.py b/absl/testing/tests/absltest_py3_test.py
index d39b501..7c5f500 100644
--- a/absl/testing/tests/absltest_py3_test.py
+++ b/absl/testing/tests/absltest_py3_test.py
@@ -1,4 +1,3 @@
-# Lint as: python3
 # Copyright 2020 The Abseil Authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/absl/testing/tests/parameterized_test.py b/absl/testing/tests/parameterized_test.py
index 7f63d01..8acbd93 100644
--- a/absl/testing/tests/parameterized_test.py
+++ b/absl/testing/tests/parameterized_test.py
@@ -14,10 +14,10 @@
 
 """Tests for absl.testing.parameterized."""
 
+from collections import abc
 import sys
 import unittest
 
-from absl._collections_abc import abc
 from absl.testing import absltest
 from absl.testing import parameterized
 
diff --git a/setup.py b/setup.py
index bf67a9f..13b2353 100644
--- a/setup.py
+++ b/setup.py
@@ -31,10 +31,6 @@ except ImportError:
 if sys.version_info < (3, 6):
   raise RuntimeError('Python version 3.6+ is required.')
 
-INSTALL_REQUIRES = [
-    'six',
-]
-
 setuptools_version = tuple(
     int(x) for x in setuptools.__version__.split('.')[:2])
 
@@ -51,7 +47,7 @@ with open(_README_PATH, 'rb') as fp:
 
 setuptools.setup(
     name='absl-py',
-    version='1.0.0',
+    version='1.1.0',
     description=(
         'Abseil Python Common Libraries, '
         'see https://github.com/abseil/abseil-py.'),
@@ -62,7 +58,6 @@ setuptools.setup(
     packages=setuptools.find_packages(exclude=[
         '*.tests', '*.tests.*', 'tests.*', 'tests',
     ]),
-    install_requires=INSTALL_REQUIRES,
     include_package_data=True,
     license='Apache 2.0',
     classifiers=[
diff --git a/smoke_tests/smoke_test.sh b/smoke_tests/smoke_test.sh
index cde5185..99307a4 100755
--- a/smoke_tests/smoke_test.sh
+++ b/smoke_tests/smoke_test.sh
@@ -54,8 +54,7 @@ set -u
 trap 'deactivate' EXIT
 
 # When running macOS <= 10.12, pip 9.0.3 is required to connect to PyPI.
-# So we need to manually use the latest pip to install `six`,
-# then install absl-py. See:
+# So we need to manually use the latest pip to install absl-py. See:
 # https://mail.python.org/pipermail/distutils-sig/2018-April/032114.html
 if [[ "$(python -c "import sys; print(sys.version_info.major, sys.version_info.minor)")" == "3 6" ]]; then
   # Latest get-pip.py no longer supports Python 3.6.
@@ -64,7 +63,6 @@ else
   curl https://bootstrap.pypa.io/get-pip.py | python
 fi
 pip --version
-pip install six
 
 python --version
 python setup.py install
diff --git a/third_party/BUILD b/third_party/BUILD
deleted file mode 100644
index 7b80db4..0000000
--- a/third_party/BUILD
+++ /dev/null
@@ -1,2 +0,0 @@
-# This BUILD file is empty. It is only needed so that this directory is a bazel
-# package and its files can be referenced by `http_archive.build_file`.
diff --git a/third_party/six.BUILD b/third_party/six.BUILD
deleted file mode 100644
index a1b2f7b..0000000
--- a/third_party/six.BUILD
+++ /dev/null
@@ -1,14 +0,0 @@
-# Description:
-#   Six provides simple utilities for wrapping over differences between Python 2
-#   and Python 3.
-
-licenses(["notice"])  # MIT
-
-exports_files(["LICENSE"])
-
-py_library(
-    name = "six",
-    srcs = ["six.py"],
-    srcs_version = "PY2AND3",
-    visibility = ["//visibility:public"],
-)