diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 02709dc..7b19e5d 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -11,7 +11,7 @@ jobs:
     timeout-minutes: 10
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: ['3.7', '3.8', '3.9', '3.10']
 
     steps:
     - uses: actions/checkout@v2
diff --git a/examples.py b/examples.py
index 0c6948d..1c03383 100644
--- a/examples.py
+++ b/examples.py
@@ -1,12 +1,6 @@
 #!/usr/bin/python
 # -*- coding: utf-8 -*-
 
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import with_statement
-
 import functools
 import random
 import sys
@@ -187,7 +181,10 @@ def granular_progress_example():
         progressbar.GranularBar(markers=" ⡀⡄⡆⡇⣇⣧⣷⣿", left='', right='|'),
         progressbar.GranularBar(markers=" .oO", left='', right=''),
     ]
-    for i in progressbar.progressbar(range(100), widgets=widgets):
+    for i in progressbar.progressbar(list(range(100)), widgets=widgets):
+        time.sleep(0.03)
+
+    for i in progressbar.progressbar(iter(range(100)), widgets=widgets):
         time.sleep(0.03)
 
 
diff --git a/progressbar/__about__.py b/progressbar/__about__.py
index 35b1c9d..9847408 100644
--- a/progressbar/__about__.py
+++ b/progressbar/__about__.py
@@ -19,7 +19,7 @@
 long running operations.
 '''.strip().split())
 __email__ = 'wolph@wol.ph'
-__version__ = '3.55.0'
+__version__ = '4.0.0'
 __license__ = 'BSD'
 __copyright__ = 'Copyright 2015 Rick van Hattem (Wolph)'
 __url__ = 'https://github.com/WoLpH/python-progressbar'
diff --git a/progressbar/__init__.py b/progressbar/__init__.py
index f93ab86..33d7c71 100644
--- a/progressbar/__init__.py
+++ b/progressbar/__init__.py
@@ -1,52 +1,40 @@
 from datetime import date
 
-from .utils import (
-    len_color,
-    streams
-)
-from .shortcuts import progressbar
-
-from .widgets import (
-    Timer,
-    ETA,
-    AdaptiveETA,
-    AbsoluteETA,
-    DataSize,
-    FileTransferSpeed,
-    AdaptiveTransferSpeed,
-    AnimatedMarker,
-    Counter,
-    Percentage,
-    FormatLabel,
-    SimpleProgress,
-    Bar,
-    ReverseBar,
-    BouncingBar,
-    RotatingMarker,
-    VariableMixin,
-    MultiRangeBar,
-    MultiProgressBar,
-    GranularBar,
-    FormatLabelBar,
-    PercentageLabelBar,
-    Variable,
-    DynamicMessage,
-    FormatCustomText,
-    CurrentTime
-)
-
-from .bar import (
-    ProgressBar,
-    DataTransferBar,
-    NullBar,
-)
+from .__about__ import __author__
+from .__about__ import __version__
+from .bar import DataTransferBar
+from .bar import NullBar
+from .bar import ProgressBar
 from .base import UnknownLength
-
-
-from .__about__ import (
-    __author__,
-    __version__,
-)
+from .shortcuts import progressbar
+from .utils import len_color
+from .utils import streams
+from .widgets import AbsoluteETA
+from .widgets import AdaptiveETA
+from .widgets import AdaptiveTransferSpeed
+from .widgets import AnimatedMarker
+from .widgets import Bar
+from .widgets import BouncingBar
+from .widgets import Counter
+from .widgets import CurrentTime
+from .widgets import DataSize
+from .widgets import DynamicMessage
+from .widgets import ETA
+from .widgets import FileTransferSpeed
+from .widgets import FormatCustomText
+from .widgets import FormatLabel
+from .widgets import FormatLabelBar
+from .widgets import GranularBar
+from .widgets import MultiProgressBar
+from .widgets import MultiRangeBar
+from .widgets import Percentage
+from .widgets import PercentageLabelBar
+from .widgets import ReverseBar
+from .widgets import RotatingMarker
+from .widgets import SimpleProgress
+from .widgets import Timer
+from .widgets import Variable
+from .widgets import VariableMixin
 
 __date__ = str(date.today())
 __all__ = [
diff --git a/progressbar/bar.py b/progressbar/bar.py
index b5980e2..025471e 100644
--- a/progressbar/bar.py
+++ b/progressbar/bar.py
@@ -1,17 +1,17 @@
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import unicode_literals
-from __future__ import with_statement
+from __future__ import annotations
 
-import sys
+import logging
 import math
 import os
+import sys
 import time
 import timeit
-import logging
 import warnings
-from datetime import datetime
 from copy import deepcopy
+from datetime import datetime
+
+from python_utils import types
+
 try:  # pragma: no cover
     from collections import abc
 except ImportError:  # pragma: no cover
@@ -19,14 +19,11 @@
 
 from python_utils import converters
 
-import six
-
 from . import widgets
 from . import widgets as widgets_module  # Avoid name collision
 from . import base
 from . import utils
 
-
 logger = logging.getLogger(__name__)
 
 
@@ -58,8 +55,10 @@ class ProgressBarBase(abc.Iterable, ProgressBarMixinBase):
 
 class DefaultFdMixin(ProgressBarMixinBase):
 
-    def __init__(self, fd=sys.stderr, is_terminal=None, line_breaks=None,
-                 enable_colors=None, **kwargs):
+    def __init__(self, fd: types.IO = sys.stderr,
+                 is_terminal: bool | None = None,
+                 line_breaks: bool | None = None,
+                 enable_colors: bool | None = None, **kwargs):
         if fd is sys.stdout:
             fd = utils.streams.original_stdout
 
@@ -76,8 +75,8 @@ def __init__(self, fd=sys.stderr, is_terminal=None, line_breaks=None,
         # Check if it should overwrite the current line (suitable for
         # iteractive terminals) or write line breaks (suitable for log files)
         if line_breaks is None:
-            line_breaks = utils.env_flag('PROGRESSBAR_LINE_BREAKS', not
-                                         self.is_terminal)
+            line_breaks = utils.env_flag('PROGRESSBAR_LINE_BREAKS',
+                                         not self.is_terminal)
         self.line_breaks = line_breaks
 
         # Check if ANSI escape characters are enabled (suitable for iteractive
@@ -122,7 +121,7 @@ def finish(self, *args, **kwargs):  # pragma: no cover
 
 class ResizableMixin(ProgressBarMixinBase):
 
-    def __init__(self, term_width=None, **kwargs):
+    def __init__(self, term_width: int | None = None, **kwargs):
         ProgressBarMixinBase.__init__(self, **kwargs)
 
         self.signal_set = False
@@ -156,7 +155,8 @@ def finish(self):  # pragma: no cover
 
 class StdRedirectMixin(DefaultFdMixin):
 
-    def __init__(self, redirect_stderr=False, redirect_stdout=False, **kwargs):
+    def __init__(self, redirect_stderr: bool = False,
+                 redirect_stdout: bool = False, **kwargs):
         DefaultFdMixin.__init__(self, **kwargs)
         self.redirect_stderr = redirect_stderr
         self.redirect_stdout = redirect_stdout
@@ -179,7 +179,7 @@ def start(self, *args, **kwargs):
         utils.streams.start_capturing(self)
         DefaultFdMixin.start(self, *args, **kwargs)
 
-    def update(self, value=None):
+    def update(self, value: float = None):
         if not self.line_breaks and utils.streams.needs_clear():
             self.fd.write('\r' + ' ' * self.term_width + '\r')
 
@@ -197,7 +197,6 @@ def finish(self, end='\n'):
 
 
 class ProgressBar(StdRedirectMixin, ResizableMixin, ProgressBarBase):
-
     '''The ProgressBar class which updates and prints the bar.
 
     Args:
@@ -488,8 +487,8 @@ def data(self):
             # The seconds since the bar started
             total_seconds_elapsed=total_seconds_elapsed,
             # The seconds since the bar started modulo 60
-            seconds_elapsed=(elapsed.seconds % 60) +
-            (elapsed.microseconds / 1000000.),
+            seconds_elapsed=(elapsed.seconds % 60)
+                            + (elapsed.microseconds / 1000000.),
             # The minutes since the bar started modulo 60
             minutes_elapsed=(elapsed.seconds / 60) % 60,
             # The hours since the bar started modulo 24
@@ -585,7 +584,7 @@ def _format_widgets(self):
             elif isinstance(widget, widgets.AutoWidthWidgetBase):
                 result.append(widget)
                 expanding.insert(0, index)
-            elif isinstance(widget, six.string_types):
+            elif isinstance(widget, str):
                 result.append(widget)
                 width -= self.custom_len(widget)
             else:
@@ -795,6 +794,7 @@ class DataTransferBar(ProgressBar):
 
     This assumes that the values its given are numbers of bytes.
     '''
+
     def default_widgets(self):
         if self.max_value:
             return [
@@ -813,7 +813,6 @@ def default_widgets(self):
 
 
 class NullBar(ProgressBar):
-
     '''
     Progress bar that does absolutely nothing. Useful for single verbosity
     flags
diff --git a/progressbar/base.py b/progressbar/base.py
index a8c8e71..df278e5 100644
--- a/progressbar/base.py
+++ b/progressbar/base.py
@@ -1,7 +1,4 @@
 # -*- mode: python; coding: utf-8 -*-
-from __future__ import absolute_import
-import six
-
 
 class FalseMeta(type):
     def __bool__(self):  # pragma: no cover
@@ -13,9 +10,9 @@ def __cmp__(self, other):  # pragma: no cover
     __nonzero__ = __bool__
 
 
-class UnknownLength(six.with_metaclass(FalseMeta, object)):
+class UnknownLength(metaclass=FalseMeta):
     pass
 
 
-class Undefined(six.with_metaclass(FalseMeta, object)):
+class Undefined(metaclass=FalseMeta):
     pass
diff --git a/progressbar/utils.py b/progressbar/utils.py
index 258249f..b1be944 100644
--- a/progressbar/utils.py
+++ b/progressbar/utils.py
@@ -1,17 +1,22 @@
-from __future__ import absolute_import
+from __future__ import annotations
+
 import atexit
+import datetime
 import io
+import logging
 import os
 import re
 import sys
-import logging
-import datetime
-from python_utils.time import timedelta_to_seconds, epoch, format_time
+
+from python_utils import types
 from python_utils.converters import scale_1024
 from python_utils.terminal import get_terminal_size
+from python_utils.time import epoch
+from python_utils.time import format_time
+from python_utils.time import timedelta_to_seconds
 
-import six
-
+if types.TYPE_CHECKING:
+    from .bar import ProgressBar
 
 assert timedelta_to_seconds
 assert get_terminal_size
@@ -19,7 +24,6 @@
 assert scale_1024
 assert epoch
 
-
 ANSI_TERMS = (
     '([xe]|bv)term',
     '(sco)?ansi',
@@ -34,7 +38,8 @@
 ANSI_TERM_RE = re.compile('^({})'.format('|'.join(ANSI_TERMS)), re.IGNORECASE)
 
 
-def is_ansi_terminal(fd, is_terminal=None):  # pragma: no cover
+def is_ansi_terminal(fd: types.IO, is_terminal: bool | None = None) \
+        -> bool:  # pragma: no cover
     if is_terminal is None:
         # Jupyter Notebooks define this variable and support progress bars
         if 'JPY_PARENT_PID' in os.environ:
@@ -66,7 +71,7 @@ def is_ansi_terminal(fd, is_terminal=None):  # pragma: no cover
     return is_terminal
 
 
-def is_terminal(fd, is_terminal=None):
+def is_terminal(fd: types.IO, is_terminal: bool | None = None) -> bool:
     if is_terminal is None:
         # Full ansi support encompasses what we expect from a terminal
         is_terminal = is_ansi_terminal(True) or None
@@ -86,7 +91,8 @@ def is_terminal(fd, is_terminal=None):
     return is_terminal
 
 
-def deltas_to_seconds(*deltas, **kwargs):  # default=ValueError):
+def deltas_to_seconds(*deltas,
+                      **kwargs) -> int | float | None:  # default=ValueError):
     '''
     Convert timedeltas and seconds as int to seconds as float while coalescing
 
@@ -130,7 +136,7 @@ def deltas_to_seconds(*deltas, **kwargs):  # default=ValueError):
         return default
 
 
-def no_color(value):
+def no_color(value: types.StringTypes) -> types.StringTypes:
     '''
     Return the `value` without ANSI escape codes
 
@@ -153,7 +159,7 @@ def no_color(value):
     return re.sub(pattern, replace, value)
 
 
-def len_color(value):
+def len_color(value: types.StringTypes) -> int:
     '''
     Return the length of `value` without ANSI escape codes
 
@@ -167,7 +173,7 @@ def len_color(value):
     return len(no_color(value))
 
 
-def env_flag(name, default=None):
+def env_flag(name: str, default: bool | None = None) -> bool | None:
     '''
     Accepts environt variables formatted as y/n, yes/no, 1/0, true/false,
     on/off, and returns it as a boolean
@@ -185,17 +191,18 @@ def env_flag(name, default=None):
 
 class WrappingIO:
 
-    def __init__(self, target, capturing=False, listeners=set()):
-        self.buffer = six.StringIO()
+    def __init__(self, target: types.IO, capturing: bool = False,
+                 listeners: types.Set[ProgressBar] = None) -> None:
+        self.buffer = io.StringIO()
         self.target = target
         self.capturing = capturing
-        self.listeners = listeners
+        self.listeners = listeners or set()
         self.needs_clear = False
 
     def isatty(self):  # pragma: no cover
         return self.target.isatty()
 
-    def write(self, value):
+    def write(self, value: str) -> None:
         if self.capturing:
             self.buffer.write(value)
             if '\n' in value:  # pragma: no branch
@@ -207,10 +214,10 @@ def write(self, value):
             if '\n' in value:  # pragma: no branch
                 self.flush_target()
 
-    def flush(self):
+    def flush(self) -> None:
         self.buffer.flush()
 
-    def _flush(self):
+    def _flush(self) -> None:
         value = self.buffer.getvalue()
         if value:
             self.flush()
@@ -222,12 +229,12 @@ def _flush(self):
         # when explicitly flushing, always flush the target as well
         self.flush_target()
 
-    def flush_target(self):  # pragma: no cover
+    def flush_target(self) -> None:  # pragma: no cover
         if not self.target.closed and getattr(self.target, 'flush'):
             self.target.flush()
 
 
-class StreamWrapper(object):
+class StreamWrapper:
     '''Wrap stdout and stderr globally'''
 
     def __init__(self):
@@ -246,14 +253,14 @@ def __init__(self):
         if env_flag('WRAP_STDERR', default=False):  # pragma: no cover
             self.wrap_stderr()
 
-    def start_capturing(self, bar=None):
+    def start_capturing(self, bar: ProgressBar | None = None) -> None:
         if bar:  # pragma: no branch
             self.listeners.add(bar)
 
         self.capturing += 1
         self.update_capturing()
 
-    def stop_capturing(self, bar=None):
+    def stop_capturing(self, bar: ProgressBar | None = None) -> None:
         if bar:  # pragma: no branch
             try:
                 self.listeners.remove(bar)
@@ -263,7 +270,7 @@ def stop_capturing(self, bar=None):
         self.capturing -= 1
         self.update_capturing()
 
-    def update_capturing(self):  # pragma: no cover
+    def update_capturing(self) -> None:  # pragma: no cover
         if isinstance(self.stdout, WrappingIO):
             self.stdout.capturing = self.capturing > 0
 
@@ -273,14 +280,14 @@ def update_capturing(self):  # pragma: no cover
         if self.capturing <= 0:
             self.flush()
 
-    def wrap(self, stdout=False, stderr=False):
+    def wrap(self, stdout: bool = False, stderr: bool = False) -> None:
         if stdout:
             self.wrap_stdout()
 
         if stderr:
             self.wrap_stderr()
 
-    def wrap_stdout(self):
+    def wrap_stdout(self) -> types.IO:
         self.wrap_excepthook()
 
         if not self.wrapped_stdout:
@@ -290,7 +297,7 @@ def wrap_stdout(self):
 
         return sys.stdout
 
-    def wrap_stderr(self):
+    def wrap_stderr(self) -> types.IO:
         self.wrap_excepthook()
 
         if not self.wrapped_stderr:
@@ -300,44 +307,44 @@ def wrap_stderr(self):
 
         return sys.stderr
 
-    def unwrap_excepthook(self):
+    def unwrap_excepthook(self) -> None:
         if self.wrapped_excepthook:
             self.wrapped_excepthook -= 1
             sys.excepthook = self.original_excepthook
 
-    def wrap_excepthook(self):
+    def wrap_excepthook(self) -> None:
         if not self.wrapped_excepthook:
             logger.debug('wrapping excepthook')
             self.wrapped_excepthook += 1
             sys.excepthook = self.excepthook
 
-    def unwrap(self, stdout=False, stderr=False):
+    def unwrap(self, stdout: bool = False, stderr: bool = False) -> None:
         if stdout:
             self.unwrap_stdout()
 
         if stderr:
             self.unwrap_stderr()
 
-    def unwrap_stdout(self):
+    def unwrap_stdout(self) -> None:
         if self.wrapped_stdout > 1:
             self.wrapped_stdout -= 1
         else:
             sys.stdout = self.original_stdout
             self.wrapped_stdout = 0
 
-    def unwrap_stderr(self):
+    def unwrap_stderr(self) -> None:
         if self.wrapped_stderr > 1:
             self.wrapped_stderr -= 1
         else:
             sys.stderr = self.original_stderr
             self.wrapped_stderr = 0
 
-    def needs_clear(self):  # pragma: no cover
+    def needs_clear(self) -> bool:  # pragma: no cover
         stdout_needs_clear = getattr(self.stdout, 'needs_clear', False)
         stderr_needs_clear = getattr(self.stderr, 'needs_clear', False)
         return stderr_needs_clear or stdout_needs_clear
 
-    def flush(self):
+    def flush(self) -> None:
         if self.wrapped_stdout:  # pragma: no branch
             try:
                 self.stdout._flush()
@@ -368,12 +375,14 @@ class AttributeDict(dict):
     >>> attrs = AttributeDict(spam=123)
 
     # Reading
+
     >>> attrs['spam']
     123
     >>> attrs.spam
     123
 
     # Read after update using attribute
+
     >>> attrs.spam = 456
     >>> attrs['spam']
     456
@@ -381,6 +390,7 @@ class AttributeDict(dict):
     456
 
     # Read after update using dict access
+
     >>> attrs['spam'] = 123
     >>> attrs['spam']
     123
@@ -388,6 +398,7 @@ class AttributeDict(dict):
     123
 
     # Read after update using dict access
+
     >>> del attrs.spam
     >>> attrs['spam']
     Traceback (most recent call last):
@@ -402,16 +413,17 @@ class AttributeDict(dict):
     ...
     AttributeError: No such attribute: spam
     '''
-    def __getattr__(self, name):
+
+    def __getattr__(self, name: str) -> int:
         if name in self:
             return self[name]
         else:
             raise AttributeError("No such attribute: " + name)
 
-    def __setattr__(self, name, value):
+    def __setattr__(self, name: str, value: int) -> None:
         self[name] = value
 
-    def __delattr__(self, name):
+    def __delattr__(self, name: str) -> None:
         if name in self:
             del self[name]
         else:
diff --git a/progressbar/widgets.py b/progressbar/widgets.py
index e9c03ca..9ffb68a 100644
--- a/progressbar/widgets.py
+++ b/progressbar/widgets.py
@@ -1,30 +1,26 @@
 # -*- coding: utf-8 -*-
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import with_statement
-
 import abc
-import sys
-import pprint
 import datetime
 import functools
+import pprint
+import sys
 
 from python_utils import converters
-
-import six
+from python_utils import types
 
 from . import base
 from . import utils
 
+if types.TYPE_CHECKING:
+    from .bar import ProgressBar
+
 MAX_DATE = datetime.date.max
 MAX_TIME = datetime.time.max
 MAX_DATETIME = datetime.datetime.max
 
 
 def string_or_lambda(input_):
-    if isinstance(input_, six.string_types):
+    if isinstance(input_, str):
         def render_input(progress, data, width):
             return input_ % data
 
@@ -50,7 +46,7 @@ def create_wrapper(wrapper):
     elif not wrapper:
         return
 
-    if isinstance(wrapper, six.string_types):
+    if isinstance(wrapper, str):
         assert '{}' in wrapper, 'Expected string with {} for formatting'
     else:
         raise RuntimeError('Pass either a begin/end string as a tuple or a'
@@ -84,7 +80,7 @@ def _marker(progress, data, width):
         else:
             return marker
 
-    if isinstance(marker, six.string_types):
+    if isinstance(marker, str):
         marker = converters.to_unicode(marker)
         assert utils.len_color(marker) == 1, \
             'Markers are required to be 1 char'
@@ -160,7 +156,7 @@ def __init__(self, min_width=None, max_width=None, **kwargs):
         self.min_width = min_width
         self.max_width = max_width
 
-    def check_size(self, progress):
+    def check_size(self, progress: 'ProgressBar'):
         if self.min_width and self.min_width > progress.term_width:
             return False
         elif self.max_width and self.max_width < progress.term_width:
@@ -255,7 +251,7 @@ class FormatLabel(FormatWidgetMixin, WidgetBase):
         'value': ('value', None),
     }
 
-    def __init__(self, format, **kwargs):
+    def __init__(self, format: str, **kwargs):
         FormatWidgetMixin.__init__(self, format=format, **kwargs)
         WidgetBase.__init__(self, **kwargs)
 
@@ -811,7 +807,7 @@ class VariableMixin(object):
     '''Mixin to display a custom user variable '''
 
     def __init__(self, name, **kwargs):
-        if not isinstance(name, six.string_types):
+        if not isinstance(name, str):
             raise TypeError('Variable(): argument must be a string')
         if len(name.split()) > 1:
             raise ValueError('Variable(): argument must be single word')
@@ -980,6 +976,7 @@ def __call__(self, progress, data, width):
 
 class FormatLabelBar(FormatLabel, Bar):
     '''A bar which has a formatted label in the center.'''
+
     def __init__(self, format, **kwargs):
         FormatLabel.__init__(self, format, **kwargs)
         Bar.__init__(self, **kwargs)
@@ -997,6 +994,7 @@ def __call__(self, progress, data, width, format=None):
 
 class PercentageLabelBar(Percentage, FormatLabelBar):
     '''A bar which displays the current percentage in the center.'''
+
     # %3d adds an extra space that makes it look off-center
     # %2d keeps the label somewhat consistently in-place
     def __init__(self, format='%(percentage)2d%%', na='N/A%%', **kwargs):
@@ -1070,4 +1068,3 @@ def current_datetime(self):
 
     def current_time(self):
         return self.current_datetime().time()
-
diff --git a/setup.py b/setup.py
index d546263..f72abd0 100644
--- a/setup.py
+++ b/setup.py
@@ -4,55 +4,16 @@
 import os
 import sys
 
-from setuptools.command.test import test as TestCommand
-
-try:
-    from setuptools import setup, find_packages
-except ImportError:
-    from distutils.core import setup, find_packages
-
-
-# Not all systems use utf8 encoding by default, this works around that issue
-if sys.version_info > (3,):
-    from functools import partial
-    open = partial(open, encoding='utf8')
-
+from setuptools import setup, find_packages
 
 # To prevent importing about and thereby breaking the coverage info we use this
 # exec hack
 about = {}
-with open("progressbar/__about__.py") as fp:
+with open('progressbar/__about__.py', encoding='utf8') as fp:
     exec(fp.read(), about)
 
 
-class PyTest(TestCommand):
-    user_options = [('pytest-args=', 'a', 'Arguments to pass to pytest')]
-
-    def initialize_options(self):
-        TestCommand.initialize_options(self)
-        self.pytest_args = ''
-
-    def run_tests(self):
-        import shlex
-        # import here, cause outside the eggs aren't loaded
-        import pytest
-        errno = pytest.main(shlex.split(self.pytest_args))
-        sys.exit(errno)
-
-
 install_reqs = []
-tests_require = [
-    'flake8>=3.7.7',
-    'pytest>=4.6.9',
-    'pytest-cov>=2.6.1',
-    'freezegun>=0.3.11',
-    'sphinx>=1.8.5',
-]
-
-if sys.version_info < (2, 7):
-    tests_require += ['unittest2']
-
-
 if sys.argv[-1] == 'info':
     for k, v in about.items():
         print('%s: %s' % (k, v))
@@ -65,7 +26,6 @@ def run_tests(self):
     readme = \
         'See http://pypi.python.org/pypi/%(__package_name__)s/' % about
 
-
 if __name__ == '__main__':
     setup(
         name='progressbar2',
@@ -80,32 +40,33 @@ def run_tests(self):
         long_description=readme,
         include_package_data=True,
         install_requires=[
-            'python-utils>=2.3.0',
-            'six',
+            'python-utils>=3.0.0',
         ],
-        tests_require=tests_require,
         setup_requires=['setuptools'],
         zip_safe=False,
-        cmdclass={'test': PyTest},
         extras_require={
             'docs': [
-                'sphinx>=1.7.4',
+                'sphinx>=1.8.5',
+            ],
+            'tests': [
+                'flake8>=3.7.7',
+                'pytest>=4.6.9',
+                'pytest-cov>=2.6.1',
+                'pytest-mypy',
+                'freezegun>=0.3.11',
+                'sphinx>=1.8.5',
             ],
-            'tests': tests_require,
         },
+        python_requires='>=3.7.0',
         classifiers=[
             'Development Status :: 6 - Mature',
             'Intended Audience :: Developers',
             'License :: OSI Approved :: BSD License',
             'Natural Language :: English',
-            "Programming Language :: Python :: 2",
-            'Programming Language :: Python :: 2.7',
-            'Programming Language :: Python :: 3',
-            'Programming Language :: Python :: 3.4',
-            'Programming Language :: Python :: 3.5',
-            'Programming Language :: Python :: 3.6',
             'Programming Language :: Python :: 3.7',
             'Programming Language :: Python :: 3.8',
+            'Programming Language :: Python :: 3.9',
+            'Programming Language :: Python :: 3.10',
             'Programming Language :: Python :: Implementation :: PyPy',
         ],
     )
diff --git a/tests/test_flush.py b/tests/test_flush.py
index 7f4317e..69dc4e3 100644
--- a/tests/test_flush.py
+++ b/tests/test_flush.py
@@ -1,5 +1,3 @@
-from __future__ import print_function
-
 import time
 import progressbar
 
diff --git a/tests/test_stream.py b/tests/test_stream.py
index 235f174..6dcfcf7 100644
--- a/tests/test_stream.py
+++ b/tests/test_stream.py
@@ -1,5 +1,3 @@
-from __future__ import print_function
-
 import io
 import sys
 import pytest
diff --git a/tests/test_terminal.py b/tests/test_terminal.py
index f55f3df..997bb0d 100644
--- a/tests/test_terminal.py
+++ b/tests/test_terminal.py
@@ -1,5 +1,3 @@
-from __future__ import print_function
-
 import sys
 import time
 import signal
diff --git a/tox.ini b/tox.ini
index 9af9ca8..99d982d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,16 +1,15 @@
 [tox]
-envlist = py27, py33, py34, py35, py36, py37, py38, pypy, flake8, docs
+envlist = py37, py38, py39, py310, pypy3, flake8, docs
 skip_missing_interpreters = True
 
 [testenv]
 basepython =
-    py27: python2.7
-    py34: python3.4
-    py35: python3.5
     py36: python3.6
     py37: python3.7
     py38: python3.8
-    pypy: pypy
+    py39: python3.9
+    py310: python3.10
+    pypy3: pypy3
 
 deps = -r{toxinidir}/tests/requirements.txt
 commands = py.test --basetemp="{envtmpdir}" --confcutdir=.. {posargs}
@@ -18,7 +17,7 @@ changedir = tests
 
 [testenv:flake8]
 changedir =
-basepython = python2.7
+basepython = python3
 deps = flake8
 commands = flake8 {toxinidir}/progressbar {toxinidir}/tests {toxinidir}/examples.py
 
@@ -39,7 +38,7 @@ commands =
     sphinx-build -W -b html -d docs/_build/doctrees docs docs/_build/html {posargs}
 
 [flake8]
-ignore = W391, W504, E741
+ignore = W391, W504, E741, W503, E131
 exclude =
     docs,
     progressbar/six.py