automatic: pyupgrade --py36-plus

51 files changed, 185 insertions, 149 deletions

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 4db0949..7ab32ea 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,3 +1,4 @@
+exclude: ^tests/fixtures/example-code/
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v2.3.0
@@ -7,6 +8,11 @@ repos:
     -   id: end-of-file-fixer
     -   id: trailing-whitespace
         exclude: ^tests/fixtures/diffs/
+-   repo: https://github.com/asottile/reorder_python_imports
+    rev: v2.4.0
+    hooks:
+    -   id: reorder-python-imports
+        args: [--application-directories, '.:src', --py36-plus]
 -   repo: https://github.com/psf/black
     rev: 20.8b1
     hooks:
@@ -17,6 +23,7 @@ repos:
     rev: v2.11.0
     hooks:
     -   id: pyupgrade
+        args: [--py36-plus]
 -   repo: https://github.com/pre-commit/mirrors-mypy
     rev: v0.720
     hooks:
diff --git a/docs/source/conf.py b/docs/source/conf.py
index dd2003f..97860c9 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #
 # flake8 documentation build configuration file, created by
 # sphinx-quickstart on Tue Jan 19 07:14:10 2016.
@@ -11,9 +10,8 @@
 #
 # All configuration values have a default; values that are commented out
 # serve to show the default.
-
-import sys
 import os
+import sys
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -53,11 +51,12 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'flake8'
-copyright = u'2016, Ian Stapleton Cordasco'
-author = u'Ian Stapleton Cordasco'
+project = 'flake8'
+copyright = '2016, Ian Stapleton Cordasco'
+author = 'Ian Stapleton Cordasco'
 
 import flake8
+
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
@@ -234,8 +233,8 @@ latex_elements = {
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
-    (master_doc, 'flake8.tex', u'flake8 Documentation',
-     u'Ian Stapleton Cordasco', 'manual'),
+    (master_doc, 'flake8.tex', 'flake8 Documentation',
+     'Ian Stapleton Cordasco', 'manual'),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -264,7 +263,7 @@ latex_documents = [
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    ('manpage', 'flake8', u'Flake8 Command Line Documentation',
+    ('manpage', 'flake8', 'Flake8 Command Line Documentation',
      [author], 1)
 ]
 
@@ -278,7 +277,7 @@ man_pages = [
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-    ('index', 'Flake8', u'Flake8 Documentation', u'Tarek Ziade',
+    ('index', 'Flake8', 'Flake8 Documentation', 'Tarek Ziade',
      'Flake8', 'Code checking using pycodestyle, pyflakes and mccabe',
      'Miscellaneous'),
 ]
diff --git a/example-plugin/setup.py b/example-plugin/setup.py
index 80911a2..0facd57 100644
--- a/example-plugin/setup.py
+++ b/example-plugin/setup.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import setuptools
 
 setuptools.setup(
diff --git a/example-plugin/src/flake8_example_plugin/__init__.py b/example-plugin/src/flake8_example_plugin/__init__.py
index 33d76f3..420ce73 100644
--- a/example-plugin/src/flake8_example_plugin/__init__.py
+++ b/example-plugin/src/flake8_example_plugin/__init__.py
@@ -1,7 +1,6 @@
 """Module for an example Flake8 plugin."""
-
-from .on_by_default import ExampleOne
 from .off_by_default import ExampleTwo
+from .on_by_default import ExampleOne
 
 __all__ = (
     'ExampleOne',
diff --git a/example-plugin/src/flake8_example_plugin/off_by_default.py b/example-plugin/src/flake8_example_plugin/off_by_default.py
index d768328..50afa81 100644
--- a/example-plugin/src/flake8_example_plugin/off_by_default.py
+++ b/example-plugin/src/flake8_example_plugin/off_by_default.py
@@ -1,7 +1,7 @@
 """Our first example plugin."""
 
 
-class ExampleTwo(object):
+class ExampleTwo:
     """Second Example Plugin."""
     name = 'off-by-default-example-plugin'
     version = '1.0.0'
diff --git a/example-plugin/src/flake8_example_plugin/on_by_default.py b/example-plugin/src/flake8_example_plugin/on_by_default.py
index a324297..c748822 100644
--- a/example-plugin/src/flake8_example_plugin/on_by_default.py
+++ b/example-plugin/src/flake8_example_plugin/on_by_default.py
@@ -1,7 +1,7 @@
 """Our first example plugin."""
 
 
-class ExampleOne(object):
+class ExampleOne:
     """First Example Plugin."""
     name = 'on-by-default-example-plugin'
     version = '1.0.0'
@@ -11,5 +11,4 @@ class ExampleOne(object):
 
     def run(self):
         """Do nothing."""
-        for message in []:
-            yield message
+        yield from []
diff --git a/setup.py b/setup.py
index a64bdf2..e718512 100644
--- a/setup.py
+++ b/setup.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """Packaging logic for Flake8."""
 import os
 import sys
diff --git a/src/flake8/_compat.py b/src/flake8/_compat.py
index 85af0a3..640f2bd 100644
--- a/src/flake8/_compat.py
+++ b/src/flake8/_compat.py
@@ -1,10 +1,6 @@
 """Expose backports in a single place."""
 import sys
-
-if sys.version_info >= (3,):  # pragma: no cover (PY3+)
-    from functools import lru_cache
-else:  # pragma: no cover (<PY3)
-    from functools32 import lru_cache
+from functools import lru_cache
 
 if sys.version_info >= (3, 8):  # pragma: no cover (PY38+)
     import importlib.metadata as importlib_metadata
diff --git a/src/flake8/api/legacy.py b/src/flake8/api/legacy.py
index 7923698..f046b5c 100644
--- a/src/flake8/api/legacy.py
+++ b/src/flake8/api/legacy.py
@@ -60,7 +60,7 @@ def get_style_guide(**kwargs):
     return StyleGuide(application)
 
 
-class StyleGuide(object):
+class StyleGuide:
     """Public facing object that mimic's Flake8 2.0's StyleGuide.
 
     .. note::
@@ -170,7 +170,7 @@ class StyleGuide(object):
         return self.check_files([filename])
 
 
-class Report(object):
+class Report:
     """Public facing object that mimic's Flake8 2.0's API.
 
     .. note::
@@ -210,6 +210,6 @@ class Report(object):
             list
         """
         return [
-            "{} {} {}".format(s.count, s.error_code, s.message)
+            f"{s.count} {s.error_code} {s.message}"
             for s in self._stats.statistics_for(violation)
         ]
diff --git a/src/flake8/checker.py b/src/flake8/checker.py
index 82ce090..a9abd21 100644
--- a/src/flake8/checker.py
+++ b/src/flake8/checker.py
@@ -6,18 +6,21 @@ import logging
 import signal
 import sys
 import tokenize
-from typing import Dict, List, Optional, Tuple
-
-try:
-    import multiprocessing.pool
-except ImportError:
-    multiprocessing = None  # type: ignore
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Tuple
 
 from flake8 import defaults
 from flake8 import exceptions
 from flake8 import processor
 from flake8 import utils
 
+try:
+    import multiprocessing.pool
+except ImportError:
+    multiprocessing = None  # type: ignore
+
 LOG = logging.getLogger(__name__)
 
 SERIAL_RETRY_ERRNOS = {
@@ -48,7 +51,7 @@ def _multiprocessing_is_fork():  # type () -> bool
         return multiprocessing and not utils.is_windows()
 
 
-class Manager(object):
+class Manager:
     """Manage the parallelism and checker instances for each plugin and file.
 
     This class will be responsible for the following:
@@ -337,7 +340,7 @@ class Manager(object):
         self._process_statistics()
 
 
-class FileChecker(object):
+class FileChecker:
     """Manage running checks for a file and aggregate the results."""
 
     def __init__(self, filename, checks, options):
@@ -375,13 +378,13 @@ class FileChecker(object):
 
     def __repr__(self):  # type: () -> str
         """Provide helpful debugging representation."""
-        return "FileChecker for {}".format(self.filename)
+        return f"FileChecker for {self.filename}"
 
     def _make_processor(self):
         # type: () -> Optional[processor.FileProcessor]
         try:
             return processor.FileProcessor(self.filename, self.options)
-        except IOError as e:
+        except OSError as e:
             # If we can not read the file due to an IOError (e.g., the file
             # does not exist or we do not have the permissions to open it)
             # then we need to format that exception for the user.
diff --git a/src/flake8/exceptions.py b/src/flake8/exceptions.py
index e1b0539..bcc29de 100644
--- a/src/flake8/exceptions.py
+++ b/src/flake8/exceptions.py
@@ -24,7 +24,7 @@ class FailedToLoadPlugin(Flake8Exception):
         """Initialize our FailedToLoadPlugin exception."""
         self.plugin_name = plugin_name
         self.original_exception = exception
-        super(FailedToLoadPlugin, self).__init__(plugin_name, exception)
+        super().__init__(plugin_name, exception)
 
     def __str__(self):  # type: () -> str
         """Format our exception message."""
@@ -46,7 +46,7 @@ class InvalidSyntax(Flake8Exception):
         self.error_code = "E902"
         self.line_number = 1
         self.column_number = 0
-        super(InvalidSyntax, self).__init__(exception)
+        super().__init__(exception)
 
     def __str__(self):  # type: () -> str
         """Format our exception message."""
@@ -63,9 +63,7 @@ class PluginRequestedUnknownParameters(Flake8Exception):
         """Pop certain keyword arguments for initialization."""
         self.plugin = plugin
         self.original_exception = exception
-        super(PluginRequestedUnknownParameters, self).__init__(
-            plugin, exception
-        )
+        super().__init__(plugin, exception)
 
     def __str__(self):  # type: () -> str
         """Format our exception message."""
@@ -85,7 +83,7 @@ class PluginExecutionFailed(Flake8Exception):
         """Utilize keyword arguments for message generation."""
         self.plugin = plugin
         self.original_exception = exception
-        super(PluginExecutionFailed, self).__init__(plugin, exception)
+        super().__init__(plugin, exception)
 
     def __str__(self):  # type: () -> str
         """Format our exception message."""
diff --git a/src/flake8/formatting/base.py b/src/flake8/formatting/base.py
index ae78f49..89789b5 100644
--- a/src/flake8/formatting/base.py
+++ b/src/flake8/formatting/base.py
@@ -1,15 +1,16 @@
 """The base class and interface for all formatting plugins."""
-from __future__ import print_function
-
 import argparse
-from typing import IO, List, Optional, Tuple
+from typing import IO
+from typing import List
+from typing import Optional
+from typing import Tuple
 
 if False:  # `typing.TYPE_CHECKING` was introduced in 3.5.2
     from flake8.statistics import Statistics
     from flake8.style_guide import Violation
 
 
-class BaseFormatter(object):
+class BaseFormatter:
     """Class defining the formatter interface.
 
     .. attribute:: options
@@ -179,7 +180,7 @@ class BaseFormatter(object):
         )
         # Physical lines have a newline at the end, no need to add an extra
         # one
-        return "{}{}^".format(error.physical_line, indent)
+        return f"{error.physical_line}{indent}^"
 
     def _write(self, output):  # type: (str) -> None
         """Handle logic of whether to use an output file or print()."""
diff --git a/src/flake8/formatting/default.py b/src/flake8/formatting/default.py
index 55a5d01..0ff5a9b 100644
--- a/src/flake8/formatting/default.py
+++ b/src/flake8/formatting/default.py
@@ -1,5 +1,6 @@
 """Default formatting class for Flake8."""
-from typing import Optional, Set
+from typing import Optional
+from typing import Set
 
 from flake8.formatting import base
 
@@ -77,7 +78,7 @@ class FilenameOnly(SimpleFormatter):
         """Ensure we only print each error once."""
         if error.filename not in self.filenames_already_printed:
             self.filenames_already_printed.add(error.filename)
-            return super(FilenameOnly, self).format(error)
+            return super().format(error)
         else:
             return None
 
diff --git a/src/flake8/main/application.py b/src/flake8/main/application.py
index a247062..f5e3f10 100644
--- a/src/flake8/main/application.py
+++ b/src/flake8/main/application.py
@@ -1,11 +1,13 @@
 """Module containing the application logic for Flake8."""
-from __future__ import print_function
-
 import argparse
 import logging
 import sys
 import time
-from typing import Dict, List, Optional, Set, Tuple
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Set
+from typing import Tuple
 
 import flake8
 from flake8 import checker
@@ -14,19 +16,21 @@ from flake8 import exceptions
 from flake8 import style_guide
 from flake8 import utils
 from flake8.main import options
-from flake8.options import aggregator, config
+from flake8.options import aggregator
+from flake8.options import config
 from flake8.options import manager
 from flake8.plugins import manager as plugin_manager
 
 if False:  # `typing.TYPE_CHECKING` was introduced in 3.5.2
     from typing import Type  # `typing.Type` was introduced in 3.5.2
+
     from flake8.formatting.base import BaseFormatter
 
 
 LOG = logging.getLogger(__name__)
 
 
-class Application(object):
+class Application:
     """Abstract our application into a class."""
 
     def __init__(self, program="flake8", version=flake8.__version__):
diff --git a/src/flake8/main/cli.py b/src/flake8/main/cli.py
index 1bc9155..9456ae2 100644
--- a/src/flake8/main/cli.py
+++ b/src/flake8/main/cli.py
@@ -1,6 +1,7 @@
 """Command-line implementation of flake8."""
 import sys
-from typing import List, Optional
+from typing import List
+from typing import Optional
 
 from flake8.main import application
 
diff --git a/src/flake8/main/debug.py b/src/flake8/main/debug.py
index 83a5a11..923c894 100644
--- a/src/flake8/main/debug.py
+++ b/src/flake8/main/debug.py
@@ -1,10 +1,9 @@
 """Module containing the logic for our debugging logic."""
-from __future__ import print_function
-
 import argparse
 import json
 import platform
-from typing import Dict, List
+from typing import Dict
+from typing import List
 
 
 class DebugAction(argparse.Action):
@@ -17,7 +16,7 @@ class DebugAction(argparse.Action):
         used to delay response.
         """
         self._option_manager = kwargs.pop("option_manager")
-        super(DebugAction, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def __call__(self, parser, namespace, values, option_string=None):
         """Perform the argparse action for printing debug information."""
diff --git a/src/flake8/main/options.py b/src/flake8/main/options.py
index fdde9e1..acadbb1 100644
--- a/src/flake8/main/options.py
+++ b/src/flake8/main/options.py
@@ -78,7 +78,7 @@ class JobsArgument:
             self.n_jobs = int(arg)
         else:
             raise argparse.ArgumentTypeError(
-                "{!r} must be 'auto' or an integer.".format(arg),
+                f"{arg!r} must be 'auto' or an integer.",
             )
 
     def __str__(self):
diff --git a/src/flake8/options/aggregator.py b/src/flake8/options/aggregator.py
index bdcd6a3..0ab7357 100644
--- a/src/flake8/options/aggregator.py
+++ b/src/flake8/options/aggregator.py
@@ -5,7 +5,8 @@ applies the user-specified command-line configuration on top of it.
 """
 import argparse
 import logging
-from typing import List, Tuple
+from typing import List
+from typing import Tuple
 
 from flake8.options import config
 from flake8.options.manager import OptionManager
diff --git a/src/flake8/options/config.py b/src/flake8/options/config.py
index 3dbaae7..dccc622 100644
--- a/src/flake8/options/config.py
+++ b/src/flake8/options/config.py
@@ -3,7 +3,9 @@ import collections
 import configparser
 import logging
 import os.path
-from typing import List, Optional, Tuple
+from typing import List
+from typing import Optional
+from typing import Tuple
 
 from flake8 import utils
 
@@ -12,7 +14,7 @@ LOG = logging.getLogger(__name__)
 __all__ = ("ConfigFileFinder", "MergedConfigParser")
 
 
-class ConfigFileFinder(object):
+class ConfigFileFinder:
     """Encapsulate the logic for finding and reading config files."""
 
     def __init__(
@@ -154,7 +156,7 @@ class ConfigFileFinder(object):
         return config
 
 
-class MergedConfigParser(object):
+class MergedConfigParser:
     """Encapsulate merging different types of configuration files.
 
     This parses out the options registered that were specified in the
diff --git a/src/flake8/options/manager.py b/src/flake8/options/manager.py
index 09bf862..5e0fee2 100644
--- a/src/flake8/options/manager.py
+++ b/src/flake8/options/manager.py
@@ -5,14 +5,23 @@ import contextlib
 import enum
 import functools
 import logging
-from typing import Any, Callable, cast, Dict, Generator, List, Mapping
-from typing import Optional, Sequence, Set, Tuple, Union
+from typing import Any
+from typing import Callable
+from typing import cast
+from typing import Dict
+from typing import Generator
+from typing import List
+from typing import Mapping
+from typing import Optional
+from typing import Sequence
+from typing import Set
+from typing import Tuple
+from typing import Union
 
 from flake8 import utils
 
 if False:  # TYPE_CHECKING
-    from typing import NoReturn
-    from typing import Type
+    from typing import NoReturn, Type
 
 LOG = logging.getLogger(__name__)
 
@@ -41,7 +50,7 @@ class _CallbackAction(argparse.Action):
         self._callback = kwargs.pop("callback")
         self._callback_args = kwargs.pop("callback_args", ())
         self._callback_kwargs = kwargs.pop("callback_kwargs", {})
-        super(_CallbackAction, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def __call__(
         self,
@@ -61,7 +70,7 @@ class _CallbackAction(argparse.Action):
             values,
             parser,
             *self._callback_args,
-            **self._callback_kwargs
+            **self._callback_kwargs,
         )
 
 
@@ -70,7 +79,7 @@ def _flake8_normalize(value, *args, **kwargs):
     comma_separated_list = kwargs.pop("comma_separated_list", False)
     normalize_paths = kwargs.pop("normalize_paths", False)
     if kwargs:
-        raise TypeError("Unexpected keyword args: {}".format(kwargs))
+        raise TypeError(f"Unexpected keyword args: {kwargs}")
 
     ret = value  # type: Union[str, List[str]]
     if comma_separated_list and isinstance(ret, utils.string_types):
@@ -85,7 +94,7 @@ def _flake8_normalize(value, *args, **kwargs):
     return ret
 
 
-class Option(object):
+class Option:
     """Our wrapper around an argparse argument parsers to add features."""
 
     def __init__(
@@ -284,7 +293,7 @@ class Option(object):
         for arg in self.option_args:
             parts.append(arg)
         for k, v in self.filtered_option_kwargs.items():
-            parts.append("{}={!r}".format(k, v))
+            parts.append(f"{k}={v!r}")
         return "Option({})".format(", ".join(parts))
 
     def normalize(self, value, *normalize_args):
@@ -337,7 +346,7 @@ PluginVersion = collections.namedtuple(
 )
 
 
-class OptionManager(object):
+class OptionManager:
     """Manage Options and OptionParser while adding post-processing."""
 
     def __init__(
diff --git a/src/flake8/plugins/manager.py b/src/flake8/plugins/manager.py
index 4f482dd..ab4cbd8 100644
--- a/src/flake8/plugins/manager.py
+++ b/src/flake8/plugins/manager.py
@@ -1,6 +1,10 @@
 """Plugin loading and management logic and classes."""
 import logging
-from typing import Any, Dict, List, Optional, Set
+from typing import Any
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Set
 
 from flake8 import exceptions
 from flake8 import utils
@@ -13,7 +17,7 @@ __all__ = ("Checkers", "Plugin", "PluginManager", "ReportFormatters")
 NO_GROUP_FOUND = object()
 
 
-class Plugin(object):
+class Plugin:
     """Wrap an EntryPoint from setuptools and other logic."""
 
     def __init__(self, name, entry_point, local=False):
@@ -219,7 +223,7 @@ class Plugin(object):
             self.disable(optmanager)
 
 
-class PluginManager(object):  # pylint: disable=too-few-public-methods
+class PluginManager:  # pylint: disable=too-few-public-methods
     """Find and manage plugins consistently."""
 
     def __init__(self, namespace, local_plugins=None):
@@ -342,7 +346,7 @@ def version_for(plugin):
     return getattr(module, "__version__", None)
 
 
-class PluginTypeManager(object):
+class PluginTypeManager:
     """Parent class for most of the specific plugin types."""
 
     namespace = None  # type: str
diff --git a/src/flake8/plugins/pyflakes.py b/src/flake8/plugins/pyflakes.py
index e845483..5d51799 100644
--- a/src/flake8/plugins/pyflakes.py
+++ b/src/flake8/plugins/pyflakes.py
@@ -1,6 +1,4 @@
 """Plugin built-in to Flake8 to treat pyflakes as a plugin."""
-# -*- coding: utf-8 -*-
-from __future__ import absolute_import
 
 import os
 from typing import List
@@ -10,7 +8,6 @@ import pyflakes.checker
 
 from flake8 import utils
 
-
 FLAKE8_PYFLAKES_CODES = {
     "UnusedImport": "F401",
     "ImportShadowedByLoopVar": "F402",
@@ -96,7 +93,7 @@ class FlakesChecker(pyflakes.checker.Checker):
                 if overlaped_by:
                     with_doctest = True
 
-        super(FlakesChecker, self).__init__(
+        super().__init__(
             tree,
             filename=filename,
             withDoctest=with_doctest,
diff --git a/src/flake8/processor.py b/src/flake8/processor.py
index 8ace9a3..30c49ac 100644
--- a/src/flake8/processor.py
+++ b/src/flake8/processor.py
@@ -5,7 +5,12 @@ import contextlib
 import logging
 import sys
 import tokenize
-from typing import Any, Dict, Generator, List, Optional, Tuple
+from typing import Any
+from typing import Dict
+from typing import Generator
+from typing import List
+from typing import Optional
+from typing import Tuple
 
 import flake8
 from flake8 import defaults
@@ -25,7 +30,7 @@ _LogicalMapping = List[Tuple[int, Tuple[int, int]]]
 _Logical = Tuple[List[str], List[str], _LogicalMapping]
 
 
-class FileProcessor(object):
+class FileProcessor:
     """Processes a file and holdes state.
 
     This processes a file by generating tokens, logical and physical lines,
@@ -349,7 +354,7 @@ class FileProcessor(object):
 
     def _readlines_py2(self):
         # type: () -> List[str]
-        with open(self.filename, "rU") as fd:
+        with open(self.filename) as fd:
             return fd.readlines()
 
     def _readlines_py3(self):
diff --git a/src/flake8/statistics.py b/src/flake8/statistics.py
index 100227f..c238b8d 100644
--- a/src/flake8/statistics.py
+++ b/src/flake8/statistics.py
@@ -1,12 +1,15 @@
 """Statistic collection logic for Flake8."""
 import collections
-from typing import Dict, Generator, List, Optional
+from typing import Dict
+from typing import Generator
+from typing import List
+from typing import Optional
 
 if False:  # `typing.TYPE_CHECKING` was introduced in 3.5.2
     from flake8.style_guide import Violation
 
 
-class Statistics(object):
+class Statistics:
     """Manager of aggregated statistics for a run of Flake8."""
 
     def __init__(self):  # type: () -> None
@@ -102,7 +105,7 @@ class Key(collections.namedtuple("Key", ["filename", "code"])):
         )
 
 
-class Statistic(object):
+class Statistic:
     """Simple wrapper around the logic of each statistic.
 
     Instead of maintaining a simple but potentially hard to reason about
diff --git a/src/flake8/style_guide.py b/src/flake8/style_guide.py
index 9be0fe8..df2a036 100644
--- a/src/flake8/style_guide.py
+++ b/src/flake8/style_guide.py
@@ -7,8 +7,15 @@ import enum
 import itertools
 import linecache
 import logging
-from typing import Dict, Generator, List, Match, Optional, Sequence, Set
-from typing import Tuple, Union
+from typing import Dict
+from typing import Generator
+from typing import List
+from typing import Match
+from typing import Optional
+from typing import Sequence
+from typing import Set
+from typing import Tuple
+from typing import Union
 
 from flake8 import defaults
 from flake8 import statistics
@@ -142,7 +149,7 @@ class Violation(_Violation):
         return self.line_number in line_numbers
 
 
-class DecisionEngine(object):
+class DecisionEngine:
     """A class for managing the decision process around violations.
 
     This contains the logic for whether a violation should be reported or
@@ -318,7 +325,7 @@ class DecisionEngine(object):
         return decision
 
 
-class StyleGuideManager(object):
+class StyleGuideManager:
     """Manage multiple style guides for a single run."""
 
     def __init__(
@@ -437,7 +444,7 @@ class StyleGuideManager(object):
             guide.add_diff_ranges(diffinfo)
 
 
-class StyleGuide(object):
+class StyleGuide:
     """Manage a Flake8 user's style guide."""
 
     def __init__(
@@ -463,7 +470,7 @@ class StyleGuide(object):
 
     def __repr__(self):  # type: () -> str
         """Make it easier to debug which StyleGuide we're using."""
-        return "<StyleGuide [{}]>".format(self.filename)
+        return f"<StyleGuide [{self.filename}]>"
 
     def copy(self, filename=None, extend_ignore_with=None):
         # type: (Optional[str], Optional[Sequence[str]]) -> StyleGuide
@@ -499,7 +506,7 @@ class StyleGuide(object):
         return utils.matches_filename(
             filename,
             patterns=[self.filename],
-            log_message='{!r} does %(whether)smatch "%(path)s"'.format(self),
+            log_message=f'{self!r} does %(whether)smatch "%(path)s"',
             logger=LOG,
         )
 
diff --git a/src/flake8/utils.py b/src/flake8/utils.py
index 893571e..cd1b036 100644
--- a/src/flake8/utils.py
+++ b/src/flake8/utils.py
@@ -9,8 +9,16 @@ import platform
 import re
 import sys
 import tokenize
-from typing import Callable, Dict, Generator, List, Optional, Pattern
-from typing import Sequence, Set, Tuple, Union
+from typing import Callable
+from typing import Dict
+from typing import Generator
+from typing import List
+from typing import Optional
+from typing import Pattern
+from typing import Sequence
+from typing import Set
+from typing import Tuple
+from typing import Union
 
 from flake8 import exceptions
 from flake8._compat import lru_cache
@@ -21,7 +29,7 @@ if False:  # `typing.TYPE_CHECKING` was introduced in 3.5.2
 DIFF_HUNK_REGEXP = re.compile(r"^@@ -\d+(?:,\d+)? \+(\d+)(?:,(\d+))? @@.*$")
 COMMA_SEPARATED_LIST_RE = re.compile(r"[,\s]")
 LOCAL_PLUGIN_LIST_RE = re.compile(r"[,\t\n\r\f\v]")
-string_types = (str, type(u""))
+string_types = (str, type(""))
 
 
 def parse_comma_separated_list(value, regexp=COMMA_SEPARATED_LIST_RE):
@@ -204,18 +212,12 @@ def _stdin_get_value_py3():  # type: () -> str
 @lru_cache(maxsize=1)
 def stdin_get_value():  # type: () -> str
     """Get and cache it so plugins can use it."""
-    if sys.version_info < (3,):
-        return sys.stdin.read()
-    else:
-        return _stdin_get_value_py3()
+    return _stdin_get_value_py3()
 
 
 def stdin_get_lines():  # type: () -> List[str]
     """Return lines of stdin split according to file splitting."""
-    if sys.version_info < (3,):
-        return list(io.BytesIO(stdin_get_value()))
-    else:
-        return list(io.StringIO(stdin_get_value()))
+    return list(io.StringIO(stdin_get_value()))
 
 
 def parse_unified_diff(diff=None):
diff --git a/tests/fixtures/example-code/inline-ignores/E501.py b/tests/fixtures/example-code/inline-ignores/E501.py
index 62e5c0c..64a5dca 100644
--- a/tests/fixtures/example-code/inline-ignores/E501.py
+++ b/tests/fixtures/example-code/inline-ignores/E501.py
@@ -1,3 +1,4 @@
-from some.module.that.has.nested.sub.modules import ClassWithVeryVeryVeryVeryLongName  # noqa: E501,F401
+from some.module.that.has.nested.sub.modules import \
+    ClassWithVeryVeryVeryVeryLongName  # noqa: E501,F401
 
 # ClassWithVeryVeryVeryVeryLongName()
diff --git a/tests/integration/subdir/aplugin.py b/tests/integration/subdir/aplugin.py
index bc5f812..266e8d0 100644
--- a/tests/integration/subdir/aplugin.py
+++ b/tests/integration/subdir/aplugin.py
@@ -1,7 +1,7 @@
 """Module that is off sys.path by default, for testing local-plugin-paths."""
 
 
-class ExtensionTestPlugin2(object):
+class ExtensionTestPlugin2:
     """Extension test plugin in its own directory."""
 
     name = 'ExtensionTestPlugin2'
diff --git a/tests/integration/test_checker.py b/tests/integration/test_checker.py
index 836b543..1254bf0 100644
--- a/tests/integration/test_checker.py
+++ b/tests/integration/test_checker.py
@@ -1,5 +1,6 @@
 """Integration tests for the checker submodule."""
-import mock
+from unittest import mock
+
 import pytest
 
 from flake8 import checker
@@ -20,7 +21,7 @@ EXPECTED_RESULT_PHYSICAL_LINE = (
 )
 
 
-class PluginClass(object):
+class PluginClass:
     """Simple file plugin class yielding the expected report."""
 
     name = 'test'
diff --git a/tests/integration/test_main.py b/tests/integration/test_main.py
index e2f58c5..10ccc54 100644
--- a/tests/integration/test_main.py
+++ b/tests/integration/test_main.py
@@ -1,8 +1,8 @@
 """Integration tests for the main entrypoint of flake8."""
 import json
 import os
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8 import utils
@@ -280,13 +280,13 @@ def test_obtaining_args_from_sys_argv_when_not_explicity_provided(capsys):
 def test_cli_config_option_respected(tmp_path):
     """Test --config is used."""
     config = tmp_path / "flake8.ini"
-    config.write_text(u"""\
+    config.write_text("""\
 [flake8]
 ignore = F401
 """)
 
     py_file = tmp_path / "t.py"
-    py_file.write_text(u"import os\n")
+    py_file.write_text("import os\n")
 
     _call_main(["--config", str(config), str(py_file)])
 
@@ -294,13 +294,13 @@ ignore = F401
 def test_cli_isolated_overrides_config_option(tmp_path):
     """Test --isolated overrides --config."""
     config = tmp_path / "flake8.ini"
-    config.write_text(u"""\
+    config.write_text("""\
 [flake8]
 ignore = F401
 """)
 
     py_file = tmp_path / "t.py"
-    py_file.write_text(u"import os\n")
+    py_file.write_text("import os\n")
 
     _call_main(["--isolated", "--config", str(config), str(py_file)], retv=1)
 
diff --git a/tests/integration/test_plugins.py b/tests/integration/test_plugins.py
index 859fb69..1b6203e 100644
--- a/tests/integration/test_plugins.py
+++ b/tests/integration/test_plugins.py
@@ -1,12 +1,11 @@
 """Integration tests for plugin loading."""
 from flake8.main import application
 
-
 LOCAL_PLUGIN_CONFIG = 'tests/fixtures/config_files/local-plugin.ini'
 LOCAL_PLUGIN_PATH_CONFIG = 'tests/fixtures/config_files/local-plugin-path.ini'
 
 
-class ExtensionTestPlugin(object):
+class ExtensionTestPlugin:
     """Extension test plugin."""
 
     name = 'ExtensionTestPlugin'
@@ -24,7 +23,7 @@ class ExtensionTestPlugin(object):
         parser.add_option('--anopt')
 
 
-class ReportTestPlugin(object):
+class ReportTestPlugin:
     """Report test plugin."""
 
     name = 'ReportTestPlugin'
diff --git a/tests/unit/test_application.py b/tests/unit/test_application.py
index 51adefb..d675eaa 100644
--- a/tests/unit/test_application.py
+++ b/tests/unit/test_application.py
@@ -1,8 +1,8 @@
 """Tests for the Application class."""
 import argparse
 import sys
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8.main import application as app
diff --git a/tests/unit/test_base_formatter.py b/tests/unit/test_base_formatter.py
index ff2df7c..c48adf2 100644
--- a/tests/unit/test_base_formatter.py
+++ b/tests/unit/test_base_formatter.py
@@ -1,7 +1,7 @@
 """Tests for the BaseFormatter object."""
 import argparse
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8 import style_guide
diff --git a/tests/unit/test_checker_manager.py b/tests/unit/test_checker_manager.py
index d3e7e61..b94d0c5 100644
--- a/tests/unit/test_checker_manager.py
+++ b/tests/unit/test_checker_manager.py
@@ -1,7 +1,7 @@
 """Tests for the Manager object for FileCheckers."""
 import errno
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8 import checker
diff --git a/tests/unit/test_config_file_finder.py b/tests/unit/test_config_file_finder.py
index d21b03d..d31a692 100644
--- a/tests/unit/test_config_file_finder.py
+++ b/tests/unit/test_config_file_finder.py
@@ -1,9 +1,8 @@
-# -*- coding: utf-8 -*-
 """Tests for the ConfigFileFinder."""
 import configparser
 import os
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8.options import config
diff --git a/tests/unit/test_debug.py b/tests/unit/test_debug.py
index 6398cf9..bc31fec 100644
--- a/tests/unit/test_debug.py
+++ b/tests/unit/test_debug.py
@@ -1,5 +1,6 @@
 """Tests for our debugging module."""
-import mock
+from unittest import mock
+
 import pytest
 
 from flake8.main import debug
diff --git a/tests/unit/test_file_checker.py b/tests/unit/test_file_checker.py
index c4ee2bf..2b80919 100644
--- a/tests/unit/test_file_checker.py
+++ b/tests/unit/test_file_checker.py
@@ -1,5 +1,6 @@
 """Unit tests for the FileChecker class."""
-import mock
+from unittest import mock
+
 import pytest
 
 import flake8
@@ -50,7 +51,7 @@ def test_nonexistent_file():
 def test_raises_exception_on_failed_plugin(tmp_path, default_options):
     """Checks that a failing plugin results in PluginExecutionFailed."""
     foobar = tmp_path / 'foobar.py'
-    foobar.write_text(u"I exist!")  # Create temp file
+    foobar.write_text("I exist!")  # Create temp file
     plugin = {
         "name": "failure",
         "plugin_name": "failure",  # Both are necessary
diff --git a/tests/unit/test_file_processor.py b/tests/unit/test_file_processor.py
index b72e064..ca7f4f6 100644
--- a/tests/unit/test_file_processor.py
+++ b/tests/unit/test_file_processor.py
@@ -1,8 +1,8 @@
 """Tests for the FileProcessor class."""
 import ast
 import tokenize
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8 import processor
@@ -46,7 +46,7 @@ def test_read_lines_unknown_encoding(tmpdir, default_options):
 
 @pytest.mark.parametrize('first_line', [
     '\xEF\xBB\xBF"""Module docstring."""\n',
-    u'\uFEFF"""Module docstring."""\n',
+    '\uFEFF"""Module docstring."""\n',
 ])
 def test_strip_utf_bom(first_line, default_options):
     r"""Verify that we strip '\xEF\xBB\xBF' from the first line."""
@@ -58,7 +58,7 @@ def test_strip_utf_bom(first_line, default_options):
 
 @pytest.mark.parametrize('lines, expected', [
     (['\xEF\xBB\xBF"""Module docstring."""\n'], False),
-    ([u'\uFEFF"""Module docstring."""\n'], False),
+    (['\uFEFF"""Module docstring."""\n'], False),
     (['#!/usr/bin/python', '# flake8 is great', 'a = 1'], False),
     (['#!/usr/bin/python', '# flake8: noqa', 'a = 1'], True),
     (['#!/usr/bin/python', '# flake8:noqa', 'a = 1'], True),
@@ -130,7 +130,7 @@ def test_noqa_line_for(default_options):
     ])
 
     for i in range(1, 4):
-        assert file_processor.noqa_line_for(i) == 'Line {}\n'.format(i)
+        assert file_processor.noqa_line_for(i) == f'Line {i}\n'
 
 
 def test_noqa_line_for_continuation(default_options):
@@ -182,7 +182,7 @@ def test_next_line(default_options):
     ])
 
     for i in range(1, 4):
-        assert file_processor.next_line() == 'Line {}'.format(i)
+        assert file_processor.next_line() == f'Line {i}'
         assert file_processor.line_number == i
 
 
diff --git a/tests/unit/test_get_local_plugins.py b/tests/unit/test_get_local_plugins.py
index ec11998..0817550 100644
--- a/tests/unit/test_get_local_plugins.py
+++ b/tests/unit/test_get_local_plugins.py
@@ -1,5 +1,5 @@
 """Tests for get_local_plugins."""
-import mock
+from unittest import mock
 
 from flake8.options import config
 
diff --git a/tests/unit/test_legacy_api.py b/tests/unit/test_legacy_api.py
index 0ec839f..a1e7d50 100644
--- a/tests/unit/test_legacy_api.py
+++ b/tests/unit/test_legacy_api.py
@@ -1,8 +1,8 @@
 """Tests for Flake8's legacy API."""
 import argparse
 import os.path
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8.api import legacy as api
diff --git a/tests/unit/test_merged_config_parser.py b/tests/unit/test_merged_config_parser.py
index d446ad8..8def01b 100644
--- a/tests/unit/test_merged_config_parser.py
+++ b/tests/unit/test_merged_config_parser.py
@@ -1,7 +1,7 @@
 """Unit tests for flake8.options.config.MergedConfigParser."""
 import os
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8.options import config
diff --git a/tests/unit/test_option.py b/tests/unit/test_option.py
index ba6b672..fc0e288 100644
--- a/tests/unit/test_option.py
+++ b/tests/unit/test_option.py
@@ -1,7 +1,7 @@
 """Unit tests for flake8.options.manager.Option."""
 import functools
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8.options import manager
diff --git a/tests/unit/test_option_manager.py b/tests/unit/test_option_manager.py
index 09714b9..4dcbaa8 100644
--- a/tests/unit/test_option_manager.py
+++ b/tests/unit/test_option_manager.py
@@ -1,8 +1,8 @@
 """Unit tests for flake.options.manager.OptionManager."""
 import argparse
 import os
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8 import utils
diff --git a/tests/unit/test_plugin.py b/tests/unit/test_plugin.py
index 402eac8..204a4c2 100644
--- a/tests/unit/test_plugin.py
+++ b/tests/unit/test_plugin.py
@@ -1,7 +1,7 @@
 """Tests for flake8.plugins.manager.Plugin."""
 import argparse
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8 import exceptions
diff --git a/tests/unit/test_plugin_manager.py b/tests/unit/test_plugin_manager.py
index 9ad6aba..55c3e24 100644
--- a/tests/unit/test_plugin_manager.py
+++ b/tests/unit/test_plugin_manager.py
@@ -1,5 +1,5 @@
 """Tests for flake8.plugins.manager.PluginManager."""
-import mock
+from unittest import mock
 
 from flake8._compat import importlib_metadata
 from flake8.plugins import manager
diff --git a/tests/unit/test_plugin_type_manager.py b/tests/unit/test_plugin_type_manager.py
index 939aa8c..9d00b78 100644
--- a/tests/unit/test_plugin_type_manager.py
+++ b/tests/unit/test_plugin_type_manager.py
@@ -1,5 +1,6 @@
 """Tests for flake8.plugins.manager.PluginTypeManager."""
-import mock
+from unittest import mock
+
 import pytest
 
 from flake8 import exceptions
diff --git a/tests/unit/test_statistics.py b/tests/unit/test_statistics.py
index 16896f0..6aa4e6f 100644
--- a/tests/unit/test_statistics.py
+++ b/tests/unit/test_statistics.py
@@ -111,8 +111,8 @@ def test_statistic_for_retrieves_more_than_one_value():
     """Show this works for more than a couple statistic values."""
     aggregator = stats.Statistics()
     for i in range(50):
-        aggregator.record(make_error(code='E1{:02d}'.format(i)))
-        aggregator.record(make_error(code='W2{:02d}'.format(i)))
+        aggregator.record(make_error(code=f'E1{i:02d}'))
+        aggregator.record(make_error(code=f'W2{i:02d}'))
 
     statistics = list(aggregator.statistics_for('E'))
     assert len(statistics) == 50
diff --git a/tests/unit/test_style_guide.py b/tests/unit/test_style_guide.py
index 5503d7e..ac781f3 100644
--- a/tests/unit/test_style_guide.py
+++ b/tests/unit/test_style_guide.py
@@ -1,7 +1,7 @@
 """Tests for the flake8.style_guide.StyleGuide class."""
 import argparse
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8 import statistics
diff --git a/tests/unit/test_utils.py b/tests/unit/test_utils.py
index 4b89484..1befa8f 100644
--- a/tests/unit/test_utils.py
+++ b/tests/unit/test_utils.py
@@ -3,8 +3,8 @@ import io
 import logging
 import os
 import sys
+from unittest import mock
 
-import mock
 import pytest
 
 from flake8 import exceptions
@@ -242,7 +242,7 @@ def test_filenames_from_exclude_doesnt_exclude_directory_names(tmpdir):
 
 def test_parameters_for_class_plugin():
     """Verify that we can retrieve the parameters for a class plugin."""
-    class FakeCheck(object):
+    class FakeCheck:
         def __init__(self, tree):
             raise NotImplementedError
 
@@ -268,7 +268,7 @@ def test_parameters_for_function_plugin():
 
 def read_diff_file(filename):
     """Read the diff file in its entirety."""
-    with open(filename, 'r') as fd:
+    with open(filename) as fd:
         content = fd.read()
     return content
 
diff --git a/tests/unit/test_violation.py b/tests/unit/test_violation.py
index a3a56f0..284cd2a 100644
--- a/tests/unit/test_violation.py
+++ b/tests/unit/test_violation.py
@@ -1,5 +1,6 @@
 """Tests for the flake8.style_guide.Violation class."""
-import mock
+from unittest import mock
+
 import pytest
 
 from flake8 import style_guide
diff --git a/tox.ini b/tox.ini
index 26a60d4..821c5ce 100644
--- a/tox.ini
+++ b/tox.ini
@@ -31,7 +31,6 @@ deps =
     flake8
     flake8-bugbear
     flake8-docstrings>=1.3.1
-    flake8-import-order>=0.9
     flake8-typing-imports>=1.1
     pep8-naming
 commands =
@@ -141,5 +140,3 @@ exclude =
     .cache,
     .eggs
 max-complexity = 10
-import-order-style = google
-application-import-names = flake8