diff --git a/.github/integration-test.py b/.github/integration-test.py
index cf027fc..7e59669 100755
--- a/.github/integration-test.py
+++ b/.github/integration-test.py
@@ -25,14 +25,18 @@ def run_systemd_image(image_name, container_name, bootstrap_pip_spec):
     Container named container_name will be started.
     """
     cmd = [
-        'docker', 'run',
+        'docker',
+        'run',
         '--privileged',
-        '--mount', 'type=bind,source=/sys/fs/cgroup,target=/sys/fs/cgroup',
+        '--mount',
+        'type=bind,source=/sys/fs/cgroup,target=/sys/fs/cgroup',
         '--detach',
-        '--name', container_name,
+        '--name',
+        container_name,
         # A bit less than 1GB to ensure TLJH runs on 1GB VMs.
         # If this is changed all docs references to the required memory must be changed too.
-        '--memory', '900m',
+        '--memory',
+        '900m',
     ]
 
     if bootstrap_pip_spec:
@@ -49,51 +53,46 @@ def stop_container(container_name):
     Stop & remove docker container if it exists.
     """
     try:
-        subprocess.check_output([
-            'docker', 'inspect', container_name
-        ], stderr=subprocess.STDOUT)
+        subprocess.check_output(
+            ['docker', 'inspect', container_name], stderr=subprocess.STDOUT
+        )
     except subprocess.CalledProcessError:
         # No such container exists, nothing to do
         return
-    subprocess.check_call([
-        'docker', 'rm', '-f', container_name
-    ])
+    subprocess.check_call(['docker', 'rm', '-f', container_name])
 
 
 def run_container_command(container_name, cmd):
     """
     Run cmd in a running container with a bash shell
     """
-    proc = subprocess.run([
-        'docker', 'exec',
-        '-t', container_name,
-        '/bin/bash', '-c', cmd
-    ], check=True)
+    proc = subprocess.run(
+        ['docker', 'exec', '-t', container_name, '/bin/bash', '-c', cmd], check=True
+    )
 
 
 def copy_to_container(container_name, src_path, dest_path):
     """
     Copy files from src_path to dest_path inside container_name
     """
-    subprocess.check_call([
-        'docker', 'cp',
-        src_path, f'{container_name}:{dest_path}'
-    ])
+    subprocess.check_call(['docker', 'cp', src_path, f'{container_name}:{dest_path}'])
 
 
-def run_test(image_name, test_name, bootstrap_pip_spec, test_files, upgrade, installer_args):
+def run_test(
+    image_name, test_name, bootstrap_pip_spec, test_files, upgrade, installer_args
+):
     """
     Wrapper that sets up tljh with installer_args & runs test_name
     """
     stop_container(test_name)
     run_systemd_image(image_name, test_name, bootstrap_pip_spec)
 
-    source_path = os.path.abspath(
-        os.path.join(os.path.dirname(__file__), os.pardir)
-    )
+    source_path = os.path.abspath(os.path.join(os.path.dirname(__file__), os.pardir))
 
     copy_to_container(test_name, os.path.join(source_path, 'bootstrap/.'), '/srv/src')
-    copy_to_container(test_name, os.path.join(source_path, 'integration-tests/'), '/srv/src')
+    copy_to_container(
+        test_name, os.path.join(source_path, 'integration-tests/'), '/srv/src'
+    )
 
     # These logs can be very relevant to debug a container startup failure
     print(f"--- Start of logs from the container: {test_name}")
@@ -103,20 +102,16 @@ def run_test(image_name, test_name, bootstrap_pip_spec, test_files, upgrade, ins
     # Install TLJH from the default branch first to test upgrades
     if upgrade:
         run_container_command(
-            test_name,
-            'curl -L https://tljh.jupyter.org/bootstrap.py | python3 -'
+            test_name, 'curl -L https://tljh.jupyter.org/bootstrap.py | python3 -'
         )
 
-    run_container_command(
-        test_name,
-        f'python3 /srv/src/bootstrap.py {installer_args}'
-    )
+    run_container_command(test_name, f'python3 /srv/src/bootstrap.py {installer_args}')
 
     # Install pkgs from requirements in hub's pip, where
     # the bootstrap script installed the others
     run_container_command(
         test_name,
-        '/opt/tljh/hub/bin/python3 -m pip install -r /srv/src/integration-tests/requirements.txt'
+        '/opt/tljh/hub/bin/python3 -m pip install -r /srv/src/integration-tests/requirements.txt',
     )
     run_container_command(
         test_name,
@@ -124,8 +119,10 @@ def run_test(image_name, test_name, bootstrap_pip_spec, test_files, upgrade, ins
         # avoid a flood of logs while still understanding if multiple tests
         # would fail.
         '/opt/tljh/hub/bin/python3 -m pytest --verbose --maxfail=2 --color=yes --durations=10 --capture=no {}'.format(
-            ' '.join([os.path.join('/srv/src/integration-tests/', f) for f in test_files])
-        )
+            ' '.join(
+                [os.path.join('/srv/src/integration-tests/', f) for f in test_files]
+            )
+        ),
     )
 
 
@@ -133,15 +130,12 @@ def show_logs(container_name):
     """
     Print logs from inside container to stdout
     """
+    run_container_command(container_name, 'journalctl --no-pager')
     run_container_command(
-        container_name,
-        'journalctl --no-pager'
-    )
-    run_container_command(
-        container_name,
-        'systemctl --no-pager status jupyterhub traefik'
+        container_name, 'systemctl --no-pager status jupyterhub traefik'
     )
 
+
 def main():
     argparser = argparse.ArgumentParser()
     subparsers = argparser.add_subparsers(dest='action')
@@ -153,13 +147,9 @@ def main():
         dest="build_args",
     )
 
-    subparsers.add_parser('stop-container').add_argument(
-        'container_name'
-    )
+    subparsers.add_parser('stop-container').add_argument('container_name')
 
-    subparsers.add_parser('start-container').add_argument(
-        'container_name'
-    )
+    subparsers.add_parser('start-container').add_argument('container_name')
 
     run_parser = subparsers.add_parser('run')
     run_parser.add_argument('container_name')
@@ -173,7 +163,9 @@ def main():
     run_test_parser = subparsers.add_parser('run-test')
     run_test_parser.add_argument('--installer-args', default='')
     run_test_parser.add_argument('--upgrade', action='store_true')
-    run_test_parser.add_argument('--bootstrap-pip-spec', nargs='?', default="", type=str)
+    run_test_parser.add_argument(
+        '--bootstrap-pip-spec', nargs='?', default="", type=str
+    )
     run_test_parser.add_argument('test_name')
     run_test_parser.add_argument('test_files', nargs='+')
 
@@ -185,7 +177,14 @@ def main():
     image_name = 'tljh-systemd'
 
     if args.action == 'run-test':
-        run_test(image_name, args.test_name, args.bootstrap_pip_spec, args.test_files, args.upgrade, args.installer_args)
+        run_test(
+            image_name,
+            args.test_name,
+            args.bootstrap_pip_spec,
+            args.test_files,
+            args.upgrade,
+            args.installer_args,
+        )
     elif args.action == 'show-logs':
         show_logs(args.container_name)
     elif args.action == 'run':
diff --git a/bootstrap/bootstrap.py b/bootstrap/bootstrap.py
index 0315c13..14d0f67 100644
--- a/bootstrap/bootstrap.py
+++ b/bootstrap/bootstrap.py
@@ -145,20 +145,26 @@ def run_subprocess(cmd, *args, **kwargs):
     and failed output directly to the user's screen
     """
     logger = logging.getLogger('tljh')
-    proc = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, *args, **kwargs)
+    proc = subprocess.run(
+        cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, *args, **kwargs
+    )
     printable_command = ' '.join(cmd)
     if proc.returncode != 0:
         # Our process failed! Show output to the user
-        logger.error('Ran {command} with exit code {code}'.format(
-            command=printable_command, code=proc.returncode
-        ))
+        logger.error(
+            'Ran {command} with exit code {code}'.format(
+                command=printable_command, code=proc.returncode
+            )
+        )
         logger.error(proc.stdout.decode())
         raise subprocess.CalledProcessError(cmd=cmd, returncode=proc.returncode)
     else:
         # This goes into installer.log
-        logger.debug('Ran {command} with exit code {code}'.format(
-            command=printable_command, code=proc.returncode
-        ))
+        logger.debug(
+            'Ran {command} with exit code {code}'.format(
+                command=printable_command, code=proc.returncode
+            )
+        )
         # This produces multi line log output, unfortunately. Not sure how to fix.
         # For now, prioritizing human readability over machine readability.
         logger.debug(proc.stdout.decode())
@@ -169,6 +175,7 @@ def ensure_host_system_can_install_tljh():
     Check if TLJH is installable in current host system and exit with a clear
     error message otherwise.
     """
+
     def get_os_release_variable(key):
         """
         Return value for key from /etc/os-release
@@ -177,10 +184,17 @@ def ensure_host_system_can_install_tljh():
 
         Returns empty string if key is not found.
         """
-        return subprocess.check_output([
-            '/bin/bash', '-c',
-            "source /etc/os-release && echo ${{{key}}}".format(key=key)
-        ]).decode().strip()
+        return (
+            subprocess.check_output(
+                [
+                    '/bin/bash',
+                    '-c',
+                    "source /etc/os-release && echo ${{{key}}}".format(key=key),
+                ]
+            )
+            .decode()
+            .strip()
+        )
 
     # Require Ubuntu 18.04+
     distro = get_os_release_variable('ID')
@@ -203,8 +217,12 @@ def ensure_host_system_can_install_tljh():
         # Provide additional information about running in docker containers
         if os.path.exists('/.dockerenv'):
             print("Running inside a docker container without systemd isn't supported")
-            print("We recommend against running a production TLJH instance inside a docker container")
-            print("For local development, see http://tljh.jupyter.org/en/latest/contributing/dev-setup.html")
+            print(
+                "We recommend against running a production TLJH instance inside a docker container"
+            )
+            print(
+                "For local development, see http://tljh.jupyter.org/en/latest/contributing/dev-setup.html"
+            )
         sys.exit(1)
 
 
@@ -226,7 +244,7 @@ class ProgressPageRequestHandler(SimpleHTTPRequestHandler):
             return SimpleHTTPRequestHandler.do_GET(self)
         elif self.path == "/":
             self.send_response(302)
-            self.send_header('Location','/index.html')
+            self.send_header('Location', '/index.html')
             self.end_headers()
         else:
             SimpleHTTPRequestHandler.send_error(self, code=403)
@@ -243,7 +261,6 @@ def main():
     """
     ensure_host_system_can_install_tljh()
 
-
     # Various related constants
     install_prefix = os.environ.get('TLJH_INSTALL_PREFIX', '/opt/tljh')
     hub_prefix = os.path.join(install_prefix, 'hub')
@@ -251,7 +268,6 @@ def main():
     pip_bin = os.path.join(hub_prefix, 'bin', 'pip')
     initial_setup = not os.path.exists(python_bin)
 
-
     # Attempt to start a web server to serve a progress page reporting
     # installation progress.
     tljh_installer_flags = sys.argv[1:]
@@ -276,8 +292,11 @@ def main():
                     server.serve_forever()
                 except KeyboardInterrupt:
                     pass
+
             progress_page_server = HTTPServer(("", 80), ProgressPageRequestHandler)
-            p = multiprocessing.Process(target=serve_forever, args=(progress_page_server,))
+            p = multiprocessing.Process(
+                target=serve_forever, args=(progress_page_server,)
+            )
             p.start()
 
             # Pass the server's pid to the installer for later termination
@@ -285,7 +304,6 @@ def main():
         except OSError:
             pass
 
-
     # Set up logging to print to a file and to stderr
     os.makedirs(install_prefix, exist_ok=True)
     file_logger_path = os.path.join(install_prefix, 'installer.log')
@@ -304,7 +322,6 @@ def main():
 
     logger.setLevel(logging.DEBUG)
 
-
     if not initial_setup:
         logger.info('Existing TLJH installation detected, upgrading...')
     else:
@@ -324,23 +341,35 @@ def main():
         apt_get_adjusted_env = os.environ.copy()
         apt_get_adjusted_env["DEBIAN_FRONTEND"] = "noninteractive"
         run_subprocess(['apt-get', 'update'])
-        run_subprocess(['apt-get', 'install', '--yes', 'software-properties-common'], env=apt_get_adjusted_env)
+        run_subprocess(
+            ['apt-get', 'install', '--yes', 'software-properties-common'],
+            env=apt_get_adjusted_env,
+        )
         run_subprocess(['add-apt-repository', 'universe', '--yes'])
         run_subprocess(['apt-get', 'update'])
-        run_subprocess(['apt-get', 'install', '--yes', 'python3', 'python3-venv', 'python3-pip', 'git'], env=apt_get_adjusted_env)
+        run_subprocess(
+            [
+                'apt-get',
+                'install',
+                '--yes',
+                'python3',
+                'python3-venv',
+                'python3-pip',
+                'git',
+            ],
+            env=apt_get_adjusted_env,
+        )
 
         logger.info('Setting up virtual environment at {}'.format(hub_prefix))
         os.makedirs(hub_prefix, exist_ok=True)
         run_subprocess(['python3', '-m', 'venv', hub_prefix])
 
-
     # Upgrade pip
     # Keep pip version pinning in sync with the one in unit-test.yml!
     # See changelog at https://pip.pypa.io/en/latest/news/#changelog
     logger.info('Upgrading pip...')
     run_subprocess([pip_bin, 'install', '--upgrade', 'pip==21.3.*'])
 
-
     # Install/upgrade TLJH installer
     tljh_install_cmd = [pip_bin, 'install', '--upgrade']
     if os.environ.get('TLJH_BOOTSTRAP_DEV', 'no') == 'yes':
@@ -348,7 +377,7 @@ def main():
     tljh_install_cmd.append(
         os.environ.get(
             'TLJH_BOOTSTRAP_PIP_SPEC',
-            'git+https://github.com/jupyterhub/the-littlest-jupyterhub.git'
+            'git+https://github.com/jupyterhub/the-littlest-jupyterhub.git',
         )
     )
     if initial_setup:
@@ -357,7 +386,6 @@ def main():
         logger.info('Upgrading TLJH installer...')
     run_subprocess(tljh_install_cmd)
 
-
     # Run TLJH installer
     logger.info('Running TLJH installer...')
     os.execv(python_bin, [python_bin, '-m', 'tljh.installer'] + tljh_installer_flags)
diff --git a/docs/conf.py b/docs/conf.py
index 2558b8b..b3c283f 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -12,9 +12,7 @@ version = ''
 release = 'v0.1'
 
 # Enable MathJax for Math
-extensions = ['sphinx.ext.mathjax',
-              'sphinx.ext.intersphinx',
-              'sphinx_copybutton']
+extensions = ['sphinx.ext.mathjax', 'sphinx.ext.intersphinx', 'sphinx_copybutton']
 
 # The root toctree document.
 root_doc = master_doc = "index"
@@ -22,14 +20,13 @@ root_doc = master_doc = "index"
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 # This pattern also affects html_static_path and html_extra_path .
-exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store',
-                    'install/custom.rst']
+exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store', 'install/custom.rst']
 
 intersphinx_mapping = {
     'sphinx': ('http://www.sphinx-doc.org/en/master/', None),
 }
 
-intersphinx_cache_limit = 90 # days
+intersphinx_cache_limit = 90  # days
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'sphinx'
diff --git a/integration-tests/conftest.py b/integration-tests/conftest.py
index 82dd70e..123be8d 100644
--- a/integration-tests/conftest.py
+++ b/integration-tests/conftest.py
@@ -5,13 +5,13 @@ import os
 from pytest import fixture
 
 
-
 @fixture
 def preserve_config(request):
     """Fixture to save and restore config around tests"""
     # Import TLJH only when needed. This lets us run tests in places
     # where TLJH is not installed - particularly, the 'distro check' test.
     from tljh.config import CONFIG_FILE, reload_component
+
     if os.path.exists(CONFIG_FILE):
         with open(CONFIG_FILE) as f:
             save_config = f.read()
diff --git a/integration-tests/plugins/simplest/tljh_simplest.py b/integration-tests/plugins/simplest/tljh_simplest.py
index d9176de..7c287dd 100644
--- a/integration-tests/plugins/simplest/tljh_simplest.py
+++ b/integration-tests/plugins/simplest/tljh_simplest.py
@@ -17,12 +17,14 @@ def tljh_extra_user_pip_packages():
         'django',
     ]
 
+
 @hookimpl
 def tljh_extra_hub_pip_packages():
     return [
         'there',
     ]
 
+
 @hookimpl
 def tljh_extra_apt_packages():
     return [
@@ -33,9 +35,8 @@ def tljh_extra_apt_packages():
 @hookimpl
 def tljh_config_post_install(config):
     # Put an arbitrary marker we can test for
-    config['simplest_plugin'] = {
-        'present': True
-    }
+    config['simplest_plugin'] = {'present': True}
+
 
 @hookimpl
 def tljh_custom_jupyterhub_config(c):
diff --git a/integration-tests/test_admin_installer.py b/integration-tests/test_admin_installer.py
index 1bda5d4..f710911 100644
--- a/integration-tests/test_admin_installer.py
+++ b/integration-tests/test_admin_installer.py
@@ -19,6 +19,7 @@ async def test_admin_login():
         # If user is not logged in, this will raise an exception
         await u.ensure_server_simulate()
 
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     "username, password",
diff --git a/integration-tests/test_bootstrap.py b/integration-tests/test_bootstrap.py
index de95a46..b0cdab6 100644
--- a/integration-tests/test_bootstrap.py
+++ b/integration-tests/test_bootstrap.py
@@ -38,6 +38,7 @@ def get_bootstrap_script_location(container_name, show_progress_page):
     subprocess.check_call(["docker", "cp", source_path, f"{container_name}:/srv/src"])
     return bootstrap_script
 
+
 # FIXME: Refactor this function to easier to understand using the following
 #        parameters
 #
@@ -55,7 +56,9 @@ def get_bootstrap_script_location(container_name, show_progress_page):
 #        running against the systemd container that cab be built by
 #        integration-test.py.
 #
-def run_bootstrap_after_preparing_container(container_name, image, show_progress_page=False):
+def run_bootstrap_after_preparing_container(
+    container_name, image, show_progress_page=False
+):
     """
     1. Stops old container
     2. Starts --detached container
@@ -163,7 +166,7 @@ def test_progress_page():
             run_bootstrap_after_preparing_container,
             "progress-page",
             f"ubuntu:{os.getenv('UBUNTU_VERSION', '20.04')}",
-            True
+            True,
         )
 
         # Check if progress page started
diff --git a/integration-tests/test_extensions.py b/integration-tests/test_extensions.py
index 13b305a..776da68 100644
--- a/integration-tests/test_extensions.py
+++ b/integration-tests/test_extensions.py
@@ -6,39 +6,43 @@ def test_serverextensions():
     Validate serverextensions we want are installed
     """
     # jupyter-serverextension writes to stdout and stderr weirdly
-    proc = subprocess.run([
-        '/opt/tljh/user/bin/jupyter-serverextension',
-        'list', '--sys-prefix'
-    ], stderr=subprocess.PIPE)
+    proc = subprocess.run(
+        ['/opt/tljh/user/bin/jupyter-serverextension', 'list', '--sys-prefix'],
+        stderr=subprocess.PIPE,
+    )
 
     extensions = [
         'jupyterlab 3.',
         'nbgitpuller 1.',
         'nteract_on_jupyter 2.1.',
-        'jupyter_resource_usage'
+        'jupyter_resource_usage',
     ]
 
     for e in extensions:
         assert e in proc.stderr.decode()
 
+
 def test_nbextensions():
     """
     Validate nbextensions we want are installed & enabled
     """
     # jupyter-nbextension writes to stdout and stderr weirdly
-    proc = subprocess.run([
-        '/opt/tljh/user/bin/jupyter-nbextension',
-        'list', '--sys-prefix'
-    ], stderr=subprocess.PIPE, stdout=subprocess.PIPE)
+    proc = subprocess.run(
+        ['/opt/tljh/user/bin/jupyter-nbextension', 'list', '--sys-prefix'],
+        stderr=subprocess.PIPE,
+        stdout=subprocess.PIPE,
+    )
 
     extensions = [
         'jupyter_resource_usage/main',
         # This is what ipywidgets nbextension is called
-        'jupyter-js-widgets/extension'
+        'jupyter-js-widgets/extension',
     ]
 
     for e in extensions:
         assert f'{e} \x1b[32m enabled \x1b[0m' in proc.stdout.decode()
 
     # Ensure we have 'OK' messages in our stdout, to make sure everything is importable
-    assert proc.stderr.decode() == '      - Validating: \x1b[32mOK\x1b[0m\n' * len(extensions)
+    assert proc.stderr.decode() == '      - Validating: \x1b[32mOK\x1b[0m\n' * len(
+        extensions
+    )
diff --git a/integration-tests/test_hub.py b/integration-tests/test_hub.py
index 5e98d1a..9d56f43 100644
--- a/integration-tests/test_hub.py
+++ b/integration-tests/test_hub.py
@@ -33,8 +33,20 @@ async def test_user_code_execute():
     hub_url = 'http://localhost'
     username = secrets.token_hex(8)
 
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy')).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy'
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+        ).wait()
+    )
 
     async with User(username, hub_url, partial(login_dummy, password='')) as u:
         await u.login()
@@ -57,17 +69,48 @@ async def test_user_server_started_with_custom_base_url():
     hub_url = f"http://localhost{base_url}"
     username = secrets.token_hex(8)
 
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy')).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'base_url', base_url)).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy'
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'base_url', base_url
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+        ).wait()
+    )
 
     async with User(username, hub_url, partial(login_dummy, password='')) as u:
         await u.login()
         await u.ensure_server_simulate()
 
         # unset base_url to avoid problems with other tests
-        assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'unset', 'base_url')).wait()
-        assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+        assert (
+            0
+            == await (
+                await asyncio.create_subprocess_exec(
+                    *TLJH_CONFIG_PATH, 'unset', 'base_url'
+                )
+            ).wait()
+        )
+        assert (
+            0
+            == await (
+                await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+            ).wait()
+        )
 
 
 @pytest.mark.asyncio
@@ -80,9 +123,28 @@ async def test_user_admin_add():
     hub_url = 'http://localhost'
     username = secrets.token_hex(8)
 
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy')).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'add-item', 'users.admin', username)).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy'
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'add-item', 'users.admin', username
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+        ).wait()
+    )
 
     async with User(username, hub_url, partial(login_dummy, password='')) as u:
         await u.login()
@@ -92,8 +154,7 @@ async def test_user_admin_add():
         assert pwd.getpwnam(f'jupyter-{username}') is not None
 
         # Assert that the user has admin rights
-        assert f'jupyter-{username}' in grp.getgrnam(
-            'jupyterhub-admins').gr_mem
+        assert f'jupyter-{username}' in grp.getgrnam('jupyterhub-admins').gr_mem
 
 
 # FIXME: Make this test pass
@@ -110,9 +171,28 @@ async def test_user_admin_remove():
     hub_url = 'http://localhost'
     username = secrets.token_hex(8)
 
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy')).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'add-item', 'users.admin', username)).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy'
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'add-item', 'users.admin', username
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+        ).wait()
+    )
 
     async with User(username, hub_url, partial(login_dummy, password='')) as u:
         await u.login()
@@ -122,18 +202,28 @@ async def test_user_admin_remove():
         assert pwd.getpwnam(f'jupyter-{username}') is not None
 
         # Assert that the user has admin rights
-        assert f'jupyter-{username}' in grp.getgrnam(
-            'jupyterhub-admins').gr_mem
+        assert f'jupyter-{username}' in grp.getgrnam('jupyterhub-admins').gr_mem
 
-        assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'remove-item', 'users.admin', username)).wait()
-        assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+        assert (
+            0
+            == await (
+                await asyncio.create_subprocess_exec(
+                    *TLJH_CONFIG_PATH, 'remove-item', 'users.admin', username
+                )
+            ).wait()
+        )
+        assert (
+            0
+            == await (
+                await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+            ).wait()
+        )
 
         await u.stop_server()
         await u.ensure_server_simulate()
 
         # Assert that the user does *not* have admin rights
-        assert f'jupyter-{username}' not in grp.getgrnam(
-            'jupyterhub-admins').gr_mem
+        assert f'jupyter-{username}' not in grp.getgrnam('jupyterhub-admins').gr_mem
 
 
 @pytest.mark.asyncio
@@ -146,8 +236,20 @@ async def test_long_username():
     hub_url = 'http://localhost'
     username = secrets.token_hex(32)
 
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy')).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy'
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+        ).wait()
+    )
 
     try:
         async with User(username, hub_url, partial(login_dummy, password='')) as u:
@@ -161,11 +263,7 @@ async def test_long_username():
             await u.stop_server()
     except:
         # If we have any errors, print jupyterhub logs before exiting
-        subprocess.check_call([
-            'journalctl',
-            '-u', 'jupyterhub',
-            '--no-pager'
-        ])
+        subprocess.check_call(['journalctl', '-u', 'jupyterhub', '--no-pager'])
         raise
 
 
@@ -182,9 +280,31 @@ async def test_user_group_adding():
     # Create the group we want to add the user to
     system('groupadd somegroup')
 
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy')).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'add-item', 'users.extra_user_groups.somegroup', username)).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy'
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH,
+                'add-item',
+                'users.extra_user_groups.somegroup',
+                username,
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+        ).wait()
+    )
 
     try:
         async with User(username, hub_url, partial(login_dummy, password='')) as u:
@@ -203,11 +323,7 @@ async def test_user_group_adding():
             system('groupdel somegroup')
     except:
         # If we have any errors, print jupyterhub logs before exiting
-        subprocess.check_call([
-            'journalctl',
-            '-u', 'jupyterhub',
-            '--no-pager'
-        ])
+        subprocess.check_call(['journalctl', '-u', 'jupyterhub', '--no-pager'])
         raise
 
 
@@ -222,14 +338,47 @@ async def test_idle_server_culled():
     hub_url = 'http://localhost'
     username = secrets.token_hex(8)
 
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy'
+            )
+        ).wait()
+    )
     # Check every 10s for idle servers to cull
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'services.cull.every', "10")).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'services.cull.every', "10"
+            )
+        ).wait()
+    )
     # Apart from servers, also cull users
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'services.cull.users', "True")).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'services.cull.users', "True"
+            )
+        ).wait()
+    )
     # Cull servers and users after 60s of activity
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'services.cull.max_age', "60")).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'services.cull.max_age', "60"
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+        ).wait()
+    )
 
     async with User(username, hub_url, partial(login_dummy, password='')) as u:
         await u.login()
@@ -239,14 +388,18 @@ async def test_idle_server_culled():
         assert pwd.getpwnam(f'jupyter-{username}') is not None
 
         # Check that we can get to the user's server
-        r = await u.session.get(u.hub_url / 'hub/api/users' / username,
-                                headers={'Referer': str(u.hub_url / 'hub/')})
+        r = await u.session.get(
+            u.hub_url / 'hub/api/users' / username,
+            headers={'Referer': str(u.hub_url / 'hub/')},
+        )
         assert r.status == 200
 
         async def _check_culling_done():
             # Check that after 60s, the user and server have been culled and are not reacheable anymore
-            r = await u.session.get(u.hub_url / 'hub/api/users' / username,
-                                    headers={'Referer': str(u.hub_url / 'hub/')})
+            r = await u.session.get(
+                u.hub_url / 'hub/api/users' / username,
+                headers={'Referer': str(u.hub_url / 'hub/')},
+            )
             print(r.status)
             return r.status == 403
 
@@ -268,14 +421,47 @@ async def test_active_server_not_culled():
     hub_url = 'http://localhost'
     username = secrets.token_hex(8)
 
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'auth.type', 'dummy'
+            )
+        ).wait()
+    )
     # Check every 10s for idle servers to cull
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'services.cull.every', "10")).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'services.cull.every', "10"
+            )
+        ).wait()
+    )
     # Apart from servers, also cull users
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'services.cull.users', "True")).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'services.cull.users', "True"
+            )
+        ).wait()
+    )
     # Cull servers and users after 60s of activity
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'set', 'services.cull.max_age', "60")).wait()
-    assert 0 == await (await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')).wait()
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(
+                *TLJH_CONFIG_PATH, 'set', 'services.cull.max_age', "60"
+            )
+        ).wait()
+    )
+    assert (
+        0
+        == await (
+            await asyncio.create_subprocess_exec(*TLJH_CONFIG_PATH, 'reload')
+        ).wait()
+    )
 
     async with User(username, hub_url, partial(login_dummy, password='')) as u:
         await u.login()
@@ -285,14 +471,18 @@ async def test_active_server_not_culled():
         assert pwd.getpwnam(f'jupyter-{username}') is not None
 
         # Check that we can get to the user's server
-        r = await u.session.get(u.hub_url / 'hub/api/users' / username,
-                                headers={'Referer': str(u.hub_url / 'hub/')})
+        r = await u.session.get(
+            u.hub_url / 'hub/api/users' / username,
+            headers={'Referer': str(u.hub_url / 'hub/')},
+        )
         assert r.status == 200
 
         async def _check_culling_done():
             # Check that after 30s, we can still reach the user's server
-            r = await u.session.get(u.hub_url / 'hub/api/users' / username,
-                                    headers={'Referer': str(u.hub_url / 'hub/')})
+            r = await u.session.get(
+                u.hub_url / 'hub/api/users' / username,
+                headers={'Referer': str(u.hub_url / 'hub/')},
+            )
             print(r.status)
             return r.status != 200
 
diff --git a/integration-tests/test_install.py b/integration-tests/test_install.py
index 58f2815..8d2b06d 100644
--- a/integration-tests/test_install.py
+++ b/integration-tests/test_install.py
@@ -172,7 +172,16 @@ def test_pip_install(group, allowed):
         # get a failure if the user can't install to the global site. Which is
         # what we wanted to test for here.
         subprocess.check_call(
-            [python, "-m", "pip", "install", "--no-user", "--ignore-installed", "--no-deps", "flit"],
+            [
+                python,
+                "-m",
+                "pip",
+                "install",
+                "--no-user",
+                "--ignore-installed",
+                "--no-deps",
+                "flit",
+            ],
             preexec_fn=partial(setgroup, group),
         )
     if allowed:
diff --git a/integration-tests/test_proxy.py b/integration-tests/test_proxy.py
index 63e4841..2cb78f7 100644
--- a/integration-tests/test_proxy.py
+++ b/integration-tests/test_proxy.py
@@ -90,7 +90,6 @@ def test_manual_https(preserve_config):
     )
     assert resp.code == 200
 
-
     # cleanup
     shutil.rmtree(ssl_dir)
     set_config_value(CONFIG_FILE, "https.enabled", False)
@@ -105,7 +104,6 @@ def test_extra_traefik_config():
     dynamic_config_dir = os.path.join(STATE_DIR, "rules")
     os.makedirs(dynamic_config_dir, exist_ok=True)
 
-
     extra_static_config = {
         "entryPoints": {"no_auth_api": {"address": "127.0.0.1:9999"}},
         "api": {"dashboard": True, "entrypoint": "no_auth_api"},
@@ -126,7 +124,6 @@ def test_extra_traefik_config():
         },
     }
 
-
     success = False
     for i in range(5):
         time.sleep(i)
diff --git a/integration-tests/test_simplest_plugin.py b/integration-tests/test_simplest_plugin.py
index e61bbcc..7888369 100644
--- a/integration-tests/test_simplest_plugin.py
+++ b/integration-tests/test_simplest_plugin.py
@@ -23,28 +23,16 @@ def test_pip_packages():
     """
     Test extra user & hub pip packages are installed
     """
-    subprocess.check_call([
-        f'{USER_ENV_PREFIX}/bin/python3',
-        '-c',
-        'import django'
-    ])
+    subprocess.check_call([f'{USER_ENV_PREFIX}/bin/python3', '-c', 'import django'])
 
-    subprocess.check_call([
-        f'{HUB_ENV_PREFIX}/bin/python3',
-        '-c',
-        'import there'
-    ])
+    subprocess.check_call([f'{HUB_ENV_PREFIX}/bin/python3', '-c', 'import there'])
 
 
 def test_conda_packages():
     """
     Test extra user conda packages are installed
     """
-    subprocess.check_call([
-        f'{USER_ENV_PREFIX}/bin/python3',
-        '-c',
-        'import hypothesis'
-    ])
+    subprocess.check_call([f'{USER_ENV_PREFIX}/bin/python3', '-c', 'import hypothesis'])
 
 
 def test_config_hook():
@@ -80,7 +68,7 @@ def test_new_user_create():
     """
     Test that plugin receives username as arg
     """
-    username="user1"
+    username = "user1"
     # Call ensure_user to make sure the user plugin gets called
     user.ensure_user(username)
 
diff --git a/tests/test_conda.py b/tests/test_conda.py
index 7632673..19ccd1a 100644
--- a/tests/test_conda.py
+++ b/tests/test_conda.py
@@ -16,16 +16,22 @@ def prefix():
     # see https://github.com/conda-forge/miniforge/releases
     mambaforge_version = '4.10.3-7'
     if os.uname().machine == 'aarch64':
-        installer_sha256 = "ac95f137b287b3408e4f67f07a284357b1119ee157373b788b34e770ef2392b2"
+        installer_sha256 = (
+            "ac95f137b287b3408e4f67f07a284357b1119ee157373b788b34e770ef2392b2"
+        )
     elif os.uname().machine == 'x86_64':
-        installer_sha256 = "fc872522ec427fcab10167a93e802efaf251024b58cc27b084b915a9a73c4474"
-    installer_url = "https://github.com/conda-forge/miniforge/releases/download/{v}/Mambaforge-{v}-Linux-{arch}.sh".format(v=mambaforge_version, arch=os.uname().machine)
+        installer_sha256 = (
+            "fc872522ec427fcab10167a93e802efaf251024b58cc27b084b915a9a73c4474"
+        )
+    installer_url = "https://github.com/conda-forge/miniforge/releases/download/{v}/Mambaforge-{v}-Linux-{arch}.sh".format(
+        v=mambaforge_version, arch=os.uname().machine
+    )
     with tempfile.TemporaryDirectory() as tmpdir:
-        with conda.download_miniconda_installer(installer_url, installer_sha256) as installer_path:
+        with conda.download_miniconda_installer(
+            installer_url, installer_sha256
+        ) as installer_path:
             conda.install_miniconda(installer_path, tmpdir)
-        conda.ensure_conda_packages(tmpdir, [
-            'conda==4.10.3'
-        ])
+        conda.ensure_conda_packages(tmpdir, ['conda==4.10.3'])
         yield tmpdir
 
 
@@ -35,11 +41,7 @@ def test_ensure_packages(prefix):
     """
     conda.ensure_conda_packages(prefix, ['numpy'])
     # Throws an error if this fails
-    subprocess.check_call([
-        os.path.join(prefix, 'bin', 'python'),
-        '-c',
-        'import numpy'
-    ])
+    subprocess.check_call([os.path.join(prefix, 'bin', 'python'), '-c', 'import numpy'])
 
 
 def test_ensure_pip_packages(prefix):
@@ -49,11 +51,7 @@ def test_ensure_pip_packages(prefix):
     conda.ensure_conda_packages(prefix, ['pip'])
     conda.ensure_pip_packages(prefix, ['numpy'])
     # Throws an error if this fails
-    subprocess.check_call([
-        os.path.join(prefix, 'bin', 'python'),
-        '-c',
-        'import numpy'
-    ])
+    subprocess.check_call([os.path.join(prefix, 'bin', 'python'), '-c', 'import numpy'])
 
 
 def test_ensure_pip_requirements(prefix):
@@ -66,8 +64,4 @@ def test_ensure_pip_requirements(prefix):
         f.write(b'there')
         f.flush()
         conda.ensure_pip_requirements(prefix, f.name)
-    subprocess.check_call([
-        os.path.join(prefix, 'bin', 'python'),
-        '-c',
-        'import there'
-    ])
+    subprocess.check_call([os.path.join(prefix, 'bin', 'python'), '-c', 'import there'])
diff --git a/tests/test_config.py b/tests/test_config.py
index d7bba6c..0f63d25 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -32,10 +32,7 @@ def test_set_multi_level():
     new_conf = config.set_item_in_config(conf, 'a.b', 'c')
     new_conf = config.set_item_in_config(new_conf, 'a.d', 'e')
     new_conf = config.set_item_in_config(new_conf, 'f', 'g')
-    assert new_conf == {
-        'a': {'b': 'c', 'd': 'e'},
-        'f': 'g'
-    }
+    assert new_conf == {'a': {'b': 'c', 'd': 'e'}, 'f': 'g'}
 
 
 def test_set_overwrite():
@@ -44,9 +41,7 @@ def test_set_overwrite():
 
     This might be surprising destructive behavior to some :D
     """
-    conf = {
-        'a': 'b'
-    }
+    conf = {'a': 'b'}
 
     new_conf = config.set_item_in_config(conf, 'a', 'c')
     assert new_conf == {'a': 'c'}
@@ -73,16 +68,10 @@ def test_unset_one_level():
 
 
 def test_unset_multi_level():
-    conf = {
-        'a': {'b': 'c', 'd': 'e'},
-        'f': 'g'
-    }
+    conf = {'a': {'b': 'c', 'd': 'e'}, 'f': 'g'}
 
     new_conf = config.unset_item_from_config(conf, 'a.b')
-    assert new_conf == {
-        'a': {'d': 'e'},
-        'f': 'g'
-    }
+    assert new_conf == {'a': {'d': 'e'}, 'f': 'g'}
     new_conf = config.unset_item_from_config(new_conf, 'a.d')
     assert new_conf == {'f': 'g'}
     new_conf = config.unset_item_from_config(new_conf, 'f')
@@ -90,9 +79,7 @@ def test_unset_multi_level():
 
 
 def test_unset_and_clean_empty_configs():
-    conf = {
-        'a': {'b': {'c': {'d': {'e': 'f'}}}}
-    }
+    conf = {'a': {'b': {'c': {'d': {'e': 'f'}}}}}
 
     new_conf = config.unset_item_from_config(conf, 'a.b.c.d.e')
     assert new_conf == {}
@@ -113,32 +100,24 @@ def test_add_to_config_one_level():
     conf = {}
 
     new_conf = config.add_item_to_config(conf, 'a.b', 'c')
-    assert new_conf == {
-        'a': {'b': ['c']}
-    }
+    assert new_conf == {'a': {'b': ['c']}}
 
 
 def test_add_to_config_zero_level():
     conf = {}
 
     new_conf = config.add_item_to_config(conf, 'a', 'b')
-    assert new_conf == {
-        'a': ['b']
-    }
+    assert new_conf == {'a': ['b']}
 
 
 def test_add_to_config_multiple():
     conf = {}
 
     new_conf = config.add_item_to_config(conf, 'a.b.c', 'd')
-    assert new_conf == {
-        'a': {'b': {'c': ['d']}}
-    }
+    assert new_conf == {'a': {'b': {'c': ['d']}}}
 
     new_conf = config.add_item_to_config(new_conf, 'a.b.c', 'e')
-    assert new_conf == {
-        'a': {'b': {'c': ['d', 'e']}}
-    }
+    assert new_conf == {'a': {'b': {'c': ['d', 'e']}}}
 
 
 def test_remove_from_config():
@@ -146,14 +125,10 @@ def test_remove_from_config():
 
     new_conf = config.add_item_to_config(conf, 'a.b.c', 'd')
     new_conf = config.add_item_to_config(new_conf, 'a.b.c', 'e')
-    assert new_conf == {
-        'a': {'b': {'c': ['d', 'e']}}
-    }
+    assert new_conf == {'a': {'b': {'c': ['d', 'e']}}}
 
     new_conf = config.remove_item_from_config(new_conf, 'a.b.c', 'e')
-    assert new_conf == {
-        'a': {'b': {'c': ['d']}}
-    }
+    assert new_conf == {'a': {'b': {'c': ['d']}}}
 
 
 def test_remove_from_config_error():
@@ -193,13 +168,7 @@ def test_cli_no_command(capsys):
     assert "positional arguments:" in captured.out
 
 
-@pytest.mark.parametrize(
-    "arg, value",
-    [
-        ("true", True),
-        ("FALSE", False)
-    ]
-)
+@pytest.mark.parametrize("arg, value", [("true", True), ("FALSE", False)])
 def test_cli_set_bool(tljh_dir, arg, value):
     config.main(["set", "https.enabled", arg])
     cfg = configurer.load_config()
diff --git a/tests/test_configurer.py b/tests/test_configurer.py
index 8865687..432c86f 100644
--- a/tests/test_configurer.py
+++ b/tests/test_configurer.py
@@ -9,9 +9,6 @@ import sys
 from tljh import configurer
 
 
-
-
-
 def apply_mock_config(overrides):
     """
     Configure a mock configurer with given overrides.
@@ -86,7 +83,10 @@ def test_auth_default():
     """
     c = apply_mock_config({})
 
-    assert c.JupyterHub.authenticator_class == 'firstuseauthenticator.FirstUseAuthenticator'
+    assert (
+        c.JupyterHub.authenticator_class
+        == 'firstuseauthenticator.FirstUseAuthenticator'
+    )
     # Do not auto create users who haven't been manually added by default
     assert not c.FirstUseAuthenticator.create_users
 
@@ -95,14 +95,9 @@ def test_auth_dummy():
     """
     Test setting Dummy Authenticator & password
     """
-    c = apply_mock_config({
-        'auth': {
-            'type': 'dummy',
-            'DummyAuthenticator': {
-                'password': 'test'
-            }
-        }
-    })
+    c = apply_mock_config(
+        {'auth': {'type': 'dummy', 'DummyAuthenticator': {'password': 'test'}}}
+    )
     assert c.JupyterHub.authenticator_class == 'dummy'
     assert c.DummyAuthenticator.password == 'test'
 
@@ -111,33 +106,32 @@ def test_user_groups():
     """
     Test setting user groups
     """
-    c = apply_mock_config({
-        'users': {
-            'extra_user_groups': {
-                "g1": ["u1", "u2"],
-                "g2": ["u3", "u4"]
-            },
+    c = apply_mock_config(
+        {
+            'users': {
+                'extra_user_groups': {"g1": ["u1", "u2"], "g2": ["u3", "u4"]},
+            }
         }
-    })
-    assert c.UserCreatingSpawner.user_groups == {
-        "g1": ["u1", "u2"],
-        "g2": ["u3", "u4"]
-    }
+    )
+    assert c.UserCreatingSpawner.user_groups == {"g1": ["u1", "u2"], "g2": ["u3", "u4"]}
 
 
 def test_auth_firstuse():
     """
     Test setting FirstUse Authenticator options
     """
-    c = apply_mock_config({
-        'auth': {
-            'type': 'firstuseauthenticator.FirstUseAuthenticator',
-            'FirstUseAuthenticator': {
-                'create_users': True
+    c = apply_mock_config(
+        {
+            'auth': {
+                'type': 'firstuseauthenticator.FirstUseAuthenticator',
+                'FirstUseAuthenticator': {'create_users': True},
             }
         }
-    })
-    assert c.JupyterHub.authenticator_class == 'firstuseauthenticator.FirstUseAuthenticator'
+    )
+    assert (
+        c.JupyterHub.authenticator_class
+        == 'firstuseauthenticator.FirstUseAuthenticator'
+    )
     assert c.FirstUseAuthenticator.create_users
 
 
@@ -145,16 +139,20 @@ def test_auth_github():
     """
     Test using GitHub authenticator
     """
-    c = apply_mock_config({
-        'auth': {
-            'type': 'oauthenticator.github.GitHubOAuthenticator',
-            'GitHubOAuthenticator': {
-                'client_id': 'something',
-                'client_secret': 'something-else'
+    c = apply_mock_config(
+        {
+            'auth': {
+                'type': 'oauthenticator.github.GitHubOAuthenticator',
+                'GitHubOAuthenticator': {
+                    'client_id': 'something',
+                    'client_secret': 'something-else',
+                },
             }
         }
-    })
-    assert c.JupyterHub.authenticator_class == 'oauthenticator.github.GitHubOAuthenticator'
+    )
+    assert (
+        c.JupyterHub.authenticator_class == 'oauthenticator.github.GitHubOAuthenticator'
+    )
     assert c.GitHubOAuthenticator.client_id == 'something'
     assert c.GitHubOAuthenticator.client_secret == 'something-else'
 
@@ -173,12 +171,9 @@ def test_set_traefik_api():
     """
     Test setting per traefik api credentials
     """
-    c = apply_mock_config({
-        'traefik_api': {
-            'username': 'some_user',
-            'password': '1234'
-        }
-    })
+    c = apply_mock_config(
+        {'traefik_api': {'username': 'some_user', 'password': '1234'}}
+    )
     assert c.TraefikTomlProxy.traefik_api_username == 'some_user'
     assert c.TraefikTomlProxy.traefik_api_password == '1234'
 
@@ -190,40 +185,47 @@ def test_cull_service_default():
     c = apply_mock_config({})
 
     cull_cmd = [
-        sys.executable, '-m', 'jupyterhub_idle_culler',
-        '--timeout=600', '--cull-every=60', '--concurrency=5',
-        '--max-age=0'
+        sys.executable,
+        '-m',
+        'jupyterhub_idle_culler',
+        '--timeout=600',
+        '--cull-every=60',
+        '--concurrency=5',
+        '--max-age=0',
+    ]
+    assert c.JupyterHub.services == [
+        {
+            'name': 'cull-idle',
+            'admin': True,
+            'command': cull_cmd,
+        }
     ]
-    assert c.JupyterHub.services == [{
-        'name': 'cull-idle',
-        'admin': True,
-        'command': cull_cmd,
-    }]
 
 
 def test_set_cull_service():
     """
     Test setting cull service options
     """
-    c = apply_mock_config({
-        'services': {
-            'cull': {
-                'every': 10,
-                'users': True,
-                'max_age': 60
-            }
-        }
-    })
+    c = apply_mock_config(
+        {'services': {'cull': {'every': 10, 'users': True, 'max_age': 60}}}
+    )
     cull_cmd = [
-        sys.executable, '-m', 'jupyterhub_idle_culler',
-        '--timeout=600', '--cull-every=10', '--concurrency=5',
-        '--max-age=60', '--cull-users'
+        sys.executable,
+        '-m',
+        'jupyterhub_idle_culler',
+        '--timeout=600',
+        '--cull-every=10',
+        '--concurrency=5',
+        '--max-age=60',
+        '--cull-users',
+    ]
+    assert c.JupyterHub.services == [
+        {
+            'name': 'cull-idle',
+            'admin': True,
+            'command': cull_cmd,
+        }
     ]
-    assert c.JupyterHub.services == [{
-        'name': 'cull-idle',
-        'admin': True,
-        'command': cull_cmd,
-    }]
 
 
 def test_load_secrets(tljh_dir):
@@ -243,13 +245,15 @@ def test_auth_native():
     """
     Test setting Native Authenticator
     """
-    c = apply_mock_config({
-        'auth': {
-            'type': 'nativeauthenticator.NativeAuthenticator',
-            'NativeAuthenticator': {
-                'open_signup': True,
+    c = apply_mock_config(
+        {
+            'auth': {
+                'type': 'nativeauthenticator.NativeAuthenticator',
+                'NativeAuthenticator': {
+                    'open_signup': True,
+                },
             }
         }
-    })
+    )
     assert c.JupyterHub.authenticator_class == 'nativeauthenticator.NativeAuthenticator'
     assert c.NativeAuthenticator.open_signup == True
diff --git a/tests/test_installer.py b/tests/test_installer.py
index 361d394..dd4fc1a 100644
--- a/tests/test_installer.py
+++ b/tests/test_installer.py
@@ -19,20 +19,20 @@ def test_ensure_config_yaml(tljh_dir):
 
 
 @pytest.mark.parametrize(
-	"admins, expected_config",
-	[
-		([['a1'], ['a2'], ['a3']], ['a1', 'a2', 'a3']),
-		([['a1:p1'], ['a2']], ['a1', 'a2']),
-	],
+    "admins, expected_config",
+    [
+        ([['a1'], ['a2'], ['a3']], ['a1', 'a2', 'a3']),
+        ([['a1:p1'], ['a2']], ['a1', 'a2']),
+    ],
 )
 def test_ensure_admins(tljh_dir, admins, expected_config):
-	# --admin option called multiple times on the installer
-	# creates a list of argument lists.
-	installer.ensure_admins(admins)
+    # --admin option called multiple times on the installer
+    # creates a list of argument lists.
+    installer.ensure_admins(admins)
 
-	config_path = installer.CONFIG_FILE
-	with open(config_path) as f:
-	    config = yaml.load(f)
+    config_path = installer.CONFIG_FILE
+    with open(config_path) as f:
+        config = yaml.load(f)
 
-	# verify the list was flattened
-	assert config['users']['admin'] == expected_config
+    # verify the list was flattened
+    assert config['users']['admin'] == expected_config
diff --git a/tests/test_normalize.py b/tests/test_normalize.py
index 9676365..175bdd6 100644
--- a/tests/test_normalize.py
+++ b/tests/test_normalize.py
@@ -17,8 +17,7 @@ def test_generate_username():
         'jupyter-abcdefghijklmnopq': 'jupyter-abcdefghijklmnopq',
         # 27 characters, just above our cutoff for hashing
         'jupyter-abcdefghijklmnopqr': 'jupyter-abcdefghijklmnopqr-e375e',
-
     }
     for hub_user, system_user in usernames.items():
         assert generate_system_username(hub_user) == system_user
-        assert len(system_user) <= 32
\ No newline at end of file
+        assert len(system_user) <= 32
diff --git a/tests/test_traefik.py b/tests/test_traefik.py
index e858e07..ecda0ce 100644
--- a/tests/test_traefik.py
+++ b/tests/test_traefik.py
@@ -36,10 +36,8 @@ def test_default_config(tmpdir, tljh_dir):
         "http": {"address": ":80"},
         "auth_api": {
             "address": "127.0.0.1:8099",
-            "auth": {
-                "basic": {"users": [""]}
-            },
-            "whiteList": {"sourceRange": ["127.0.0.1"]}
+            "auth": {"basic": {"users": [""]}},
+            "whiteList": {"sourceRange": ["127.0.0.1"]},
         },
     }
 
@@ -72,10 +70,8 @@ def test_letsencrypt_config(tljh_dir):
         "https": {"address": ":443", "tls": {"minVersion": "VersionTLS12"}},
         "auth_api": {
             "address": "127.0.0.1:8099",
-            "auth": {
-                "basic": {"users": [""]}
-            },
-            "whiteList": {"sourceRange": ["127.0.0.1"]}
+            "auth": {"basic": {"users": [""]}},
+            "whiteList": {"sourceRange": ["127.0.0.1"]},
         },
     }
     assert cfg["acme"] == {
@@ -113,18 +109,17 @@ def test_manual_ssl_config(tljh_dir):
                 "minVersion": "VersionTLS12",
                 "certificates": [
                     {"certFile": "/path/to/ssl.cert", "keyFile": "/path/to/ssl.key"}
-                ]
+                ],
             },
         },
         "auth_api": {
             "address": "127.0.0.1:8099",
-            "auth": {
-                "basic": {"users": [""]}
-            },
-            "whiteList": {"sourceRange": ["127.0.0.1"]}
+            "auth": {"basic": {"users": [""]}},
+            "whiteList": {"sourceRange": ["127.0.0.1"]},
         },
     }
 
+
 def test_extra_config(tmpdir, tljh_dir):
     extra_config_dir = os.path.join(tljh_dir, config.CONFIG_DIR, "traefik_config.d")
     state_dir = tmpdir.mkdir("state")
@@ -146,13 +141,9 @@ def test_extra_config(tmpdir, tljh_dir):
         # modify existing value
         "logLevel": "ERROR",
         # modify existing value with multiple levels
-        "entryPoints": {
-            "auth_api": {
-                "address": "127.0.0.1:9999"
-            }
-        },
+        "entryPoints": {"auth_api": {"address": "127.0.0.1:9999"}},
         # add new setting
-        "checkNewVersion": False
+        "checkNewVersion": False,
     }
 
     with open(os.path.join(extra_config_dir, "extra.toml"), "w+") as extra_config_file:
diff --git a/tests/test_user.py b/tests/test_user.py
index 0cc079a..dc98a12 100644
--- a/tests/test_user.py
+++ b/tests/test_user.py
@@ -31,9 +31,15 @@ def test_ensure_user():
         assert os.path.exists(home_dir)
         # Ensure not word readable/writable especially in teaching context
         homedir_stats = os.stat(home_dir).st_mode
-        assert not (homedir_stats & stat.S_IROTH), "Everyone should not be able to read users home directory"
-        assert not (homedir_stats & stat.S_IWOTH), "Everyone should not be able to write users home directory"
-        assert not (homedir_stats & stat.S_IXOTH), "Everyone should not be able to list what is in users home directory"
+        assert not (
+            homedir_stats & stat.S_IROTH
+        ), "Everyone should not be able to read users home directory"
+        assert not (
+            homedir_stats & stat.S_IWOTH
+        ), "Everyone should not be able to write users home directory"
+        assert not (
+            homedir_stats & stat.S_IXOTH
+        ), "Everyone should not be able to list what is in users home directory"
 
         # Run ensure_user again, should be a noop
         user.ensure_user(username)
diff --git a/tests/test_utils.py b/tests/test_utils.py
index b123c95..555e9f2 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -8,9 +8,7 @@ def test_run_subprocess_exception(mocker):
     logger = logging.getLogger('tljh')
     mocker.patch.object(logger, 'error')
     with pytest.raises(subprocess.CalledProcessError):
-        utils.run_subprocess(
-            ['/bin/bash', '-c', 'echo error; exit 1']
-        )
+        utils.run_subprocess(['/bin/bash', '-c', 'echo error; exit 1'])
     logger.error.assert_called_with('error\n')
 
 
@@ -18,4 +16,4 @@ def test_run_subprocess(mocker):
     logger = logging.getLogger('tljh')
     mocker.patch.object(logger, 'debug')
     utils.run_subprocess(['/bin/bash', '-c', 'echo success'])
-    logger.debug.assert_called_with('success\n')
\ No newline at end of file
+    logger.debug.assert_called_with('success\n')
diff --git a/tljh/apt.py b/tljh/apt.py
index 4612958..d8efd94 100644
--- a/tljh/apt.py
+++ b/tljh/apt.py
@@ -25,7 +25,14 @@ def add_source(name, source_url, section):
     distro is determined from /etc/os-release
     """
     # lsb_release is not installed in most docker images by default
-    distro = subprocess.check_output(['/bin/bash', '-c', 'source /etc/os-release && echo ${VERSION_CODENAME}'], stderr=subprocess.STDOUT).decode().strip()
+    distro = (
+        subprocess.check_output(
+            ['/bin/bash', '-c', 'source /etc/os-release && echo ${VERSION_CODENAME}'],
+            stderr=subprocess.STDOUT,
+        )
+        .decode()
+        .strip()
+    )
     line = f'deb {source_url} {distro} {section}\n'
     with open(os.path.join('/etc/apt/sources.list.d/', name + '.list'), 'a+') as f:
         # Write out deb line only if it already doesn't exist
@@ -46,8 +53,4 @@ def install_packages(packages):
     env = os.environ.copy()
     # Stop apt from asking questions!
     env['DEBIAN_FRONTEND'] = 'noninteractive'
-    utils.run_subprocess([
-        'apt-get',
-        'install',
-        '--yes'
-    ] + packages, env=env)
+    utils.run_subprocess(['apt-get', 'install', '--yes'] + packages, env=env)
diff --git a/tljh/conda.py b/tljh/conda.py
index 7ef4099..47cf831 100644
--- a/tljh/conda.py
+++ b/tljh/conda.py
@@ -30,10 +30,14 @@ def check_miniconda_version(prefix, version):
     Return true if a miniconda install with version exists at prefix
     """
     try:
-        installed_version = subprocess.check_output([
-            os.path.join(prefix, 'bin', 'conda'),
-            '-V'
-        ], stderr=subprocess.STDOUT).decode().strip().split()[1]
+        installed_version = (
+            subprocess.check_output(
+                [os.path.join(prefix, 'bin', 'conda'), '-V'], stderr=subprocess.STDOUT
+            )
+            .decode()
+            .strip()
+            .split()[1]
+        )
         return V(installed_version) >= V(version)
     except (subprocess.CalledProcessError, FileNotFoundError):
         # Conda doesn't exist
@@ -71,9 +75,7 @@ def fix_permissions(prefix):
 
     Run after each install command.
     """
-    utils.run_subprocess(
-        ["chown", "-R", f"{os.getuid()}:{os.getgid()}", prefix]
-    )
+    utils.run_subprocess(["chown", "-R", f"{os.getuid()}:{os.getgid()}", prefix])
     utils.run_subprocess(["chmod", "-R", "o-w", prefix])
 
 
@@ -81,12 +83,7 @@ def install_miniconda(installer_path, prefix):
     """
     Install miniconda with installer at installer_path under prefix
     """
-    utils.run_subprocess([
-        '/bin/bash',
-        installer_path,
-        '-u', '-b',
-        '-p', prefix
-    ])
+    utils.run_subprocess(['/bin/bash', installer_path, '-u', '-b', '-p', prefix])
     # fix permissions on initial install
     # a few files have the wrong ownership and permissions initially
     # when the installer is run as root
@@ -106,21 +103,30 @@ def ensure_conda_packages(prefix, packages):
     # Explicitly do *not* capture stderr, since that's not always JSON!
     # Scripting conda is a PITA!
     # FIXME: raise different exception when using
-    raw_output = subprocess.check_output(conda_executable + [
-        'install',
-        '-c', 'conda-forge',  # Make customizable if we ever need to
-        '--json',
-        '--prefix', abspath
-    ] + packages).decode()
+    raw_output = subprocess.check_output(
+        conda_executable
+        + [
+            'install',
+            '-c',
+            'conda-forge',  # Make customizable if we ever need to
+            '--json',
+            '--prefix',
+            abspath,
+        ]
+        + packages
+    ).decode()
     # `conda install` outputs JSON lines for fetch updates,
     # and a undelimited output at the end. There is no reasonable way to
     # parse this outside of this kludge.
-    filtered_output = '\n'.join([
-        l for l in raw_output.split('\n')
-        # Sometimes the JSON messages start with a \x00. The lstrip removes these.
-        # conda messages seem to randomly throw \x00 in places for no reason
-        if not l.lstrip('\x00').startswith('{"fetch"')
-    ])
+    filtered_output = '\n'.join(
+        [
+            l
+            for l in raw_output.split('\n')
+            # Sometimes the JSON messages start with a \x00. The lstrip removes these.
+            # conda messages seem to randomly throw \x00 in places for no reason
+            if not l.lstrip('\x00').startswith('{"fetch"')
+        ]
+    )
     output = json.loads(filtered_output.lstrip('\x00'))
     if 'success' in output and output['success'] == True:
         return
diff --git a/tljh/config.py b/tljh/config.py
index 0609c4f..01957d0 100644
--- a/tljh/config.py
+++ b/tljh/config.py
@@ -247,7 +247,9 @@ def check_hub_ready():
     base_url = base_url[:-1] if base_url[-1] == '/' else base_url
     http_port = load_config()['http']['port']
     try:
-        r = requests.get('http://127.0.0.1:%d%s/hub/api' % (http_port, base_url), verify=False)
+        r = requests.get(
+            'http://127.0.0.1:%d%s/hub/api' % (http_port, base_url), verify=False
+        )
         return r.status_code == 200
     except:
         return False
@@ -306,13 +308,17 @@ def _is_list(item):
 def main(argv=None):
     if os.geteuid() != 0:
         print("tljh-config needs root privileges to run", file=sys.stderr)
-        print("Try using sudo before the tljh-config command you wanted to run", file=sys.stderr)
+        print(
+            "Try using sudo before the tljh-config command you wanted to run",
+            file=sys.stderr,
+        )
         sys.exit(1)
 
     if argv is None:
         argv = sys.argv[1:]
 
     from .log import init_logging
+
     try:
         init_logging()
     except Exception as e:
@@ -321,75 +327,48 @@ def main(argv=None):
 
     argparser = argparse.ArgumentParser()
     argparser.add_argument(
-        '--config-path',
-        default=CONFIG_FILE,
-        help='Path to TLJH config.yaml file'
+        '--config-path', default=CONFIG_FILE, help='Path to TLJH config.yaml file'
     )
     subparsers = argparser.add_subparsers(dest='action')
 
-    show_parser = subparsers.add_parser(
-        'show',
-        help='Show current configuration'
-    )
+    show_parser = subparsers.add_parser('show', help='Show current configuration')
 
-    unset_parser = subparsers.add_parser(
-        'unset',
-        help='Unset a configuration property'
-    )
+    unset_parser = subparsers.add_parser('unset', help='Unset a configuration property')
     unset_parser.add_argument(
-        'key_path',
-        help='Dot separated path to configuration key to unset'
+        'key_path', help='Dot separated path to configuration key to unset'
     )
 
-    set_parser = subparsers.add_parser(
-        'set',
-        help='Set a configuration property'
-    )
+    set_parser = subparsers.add_parser('set', help='Set a configuration property')
     set_parser.add_argument(
-        'key_path',
-        help='Dot separated path to configuration key to set'
-    )
-    set_parser.add_argument(
-        'value',
-        help='Value to set the configuration key to'
+        'key_path', help='Dot separated path to configuration key to set'
     )
+    set_parser.add_argument('value', help='Value to set the configuration key to')
 
     add_item_parser = subparsers.add_parser(
-        'add-item',
-        help='Add a value to a list for a configuration property'
+        'add-item', help='Add a value to a list for a configuration property'
     )
     add_item_parser.add_argument(
-        'key_path',
-        help='Dot separated path to configuration key to add value to'
-    )
-    add_item_parser.add_argument(
-        'value',
-        help='Value to add to the configuration key'
+        'key_path', help='Dot separated path to configuration key to add value to'
     )
+    add_item_parser.add_argument('value', help='Value to add to the configuration key')
 
     remove_item_parser = subparsers.add_parser(
-        'remove-item',
-        help='Remove a value from a list for a configuration property'
+        'remove-item', help='Remove a value from a list for a configuration property'
     )
     remove_item_parser.add_argument(
-        'key_path',
-        help='Dot separated path to configuration key to remove value from'
-    )
-    remove_item_parser.add_argument(
-        'value',
-        help='Value to remove from key_path'
+        'key_path', help='Dot separated path to configuration key to remove value from'
     )
+    remove_item_parser.add_argument('value', help='Value to remove from key_path')
 
     reload_parser = subparsers.add_parser(
-        'reload',
-        help='Reload a component to apply configuration change'
+        'reload', help='Reload a component to apply configuration change'
     )
     reload_parser.add_argument(
         'component',
         choices=('hub', 'proxy'),
         help='Which component to reload',
         default='hub',
-        nargs='?'
+        nargs='?',
     )
 
     args = argparser.parse_args(argv)
@@ -397,16 +376,13 @@ def main(argv=None):
     if args.action == 'show':
         show_config(args.config_path)
     elif args.action == 'set':
-        set_config_value(args.config_path, args.key_path,
-                         parse_value(args.value))
+        set_config_value(args.config_path, args.key_path, parse_value(args.value))
     elif args.action == 'unset':
         unset_config_value(args.config_path, args.key_path)
     elif args.action == 'add-item':
-        add_config_value(args.config_path, args.key_path,
-                         parse_value(args.value))
+        add_config_value(args.config_path, args.key_path, parse_value(args.value))
     elif args.action == 'remove-item':
-        remove_config_value(args.config_path, args.key_path,
-                            parse_value(args.value))
+        remove_config_value(args.config_path, args.key_path, parse_value(args.value))
     elif args.action == 'reload':
         reload_component(args.component)
     else:
diff --git a/tljh/configurer.py b/tljh/configurer.py
index 36bb69d..f22b01c 100644
--- a/tljh/configurer.py
+++ b/tljh/configurer.py
@@ -20,16 +20,9 @@ default = {
     'base_url': '/',
     'auth': {
         'type': 'firstuseauthenticator.FirstUseAuthenticator',
-        'FirstUseAuthenticator': {
-            'create_users': False
-        }
-    },
-    'users': {
-        'allowed': [],
-        'banned': [],
-        'admin': [],
-        'extra_user_groups': {}
+        'FirstUseAuthenticator': {'create_users': False},
     },
+    'users': {'allowed': [], 'banned': [], 'admin': [], 'extra_user_groups': {}},
     'limits': {
         'memory': None,
         'cpu': None,
@@ -65,12 +58,10 @@ default = {
             'every': 60,
             'concurrency': 5,
             'users': False,
-            'max_age': 0
+            'max_age': 0,
         },
-        'configurator': {
-            'enabled': False
-        }
-    }
+        'configurator': {'enabled': False},
+    },
 }
 
 
@@ -189,7 +180,9 @@ def update_auth(c, config):
         if not (auth_key[0] == auth_key[0].upper() and isinstance(auth_value, dict)):
             if auth_key == 'type':
                 continue
-            raise ValueError(f"Error: auth.{auth_key} was ignored, it didn't look like a valid configuration")
+            raise ValueError(
+                f"Error: auth.{auth_key} was ignored, it didn't look like a valid configuration"
+            )
         class_name = auth_key
         class_config_to_set = auth_value
         class_config = c[class_name]
@@ -255,9 +248,7 @@ def set_cull_idle_service(config):
     """
     Set Idle Culler service
     """
-    cull_cmd = [
-        sys.executable, '-m', 'jupyterhub_idle_culler'
-    ]
+    cull_cmd = [sys.executable, '-m', 'jupyterhub_idle_culler']
     cull_config = config['services']['cull']
     print()
 
@@ -283,8 +274,10 @@ def set_configurator(config):
     """
     HERE = os.path.abspath(os.path.dirname(__file__))
     configurator_cmd = [
-        sys.executable, "-m", "jupyterhub_configurator.app",
-        f"--Configurator.config_file={HERE}/jupyterhub_configurator_config.py"
+        sys.executable,
+        "-m",
+        "jupyterhub_configurator.app",
+        f"--Configurator.config_file={HERE}/jupyterhub_configurator_config.py",
     ]
     configurator_service = {
         'name': 'configurator',
diff --git a/tljh/hooks.py b/tljh/hooks.py
index b8c7808..8da7e11 100644
--- a/tljh/hooks.py
+++ b/tljh/hooks.py
@@ -22,6 +22,7 @@ def tljh_extra_user_pip_packages():
     """
     pass
 
+
 @hookspec
 def tljh_extra_hub_pip_packages():
     """
@@ -29,6 +30,7 @@ def tljh_extra_hub_pip_packages():
     """
     pass
 
+
 @hookspec
 def tljh_extra_apt_packages():
     """
@@ -38,6 +40,7 @@ def tljh_extra_apt_packages():
     """
     pass
 
+
 @hookspec
 def tljh_custom_jupyterhub_config(c):
     """
@@ -48,6 +51,7 @@ def tljh_custom_jupyterhub_config(c):
     """
     pass
 
+
 @hookspec
 def tljh_config_post_install(config):
     """
@@ -60,6 +64,7 @@ def tljh_config_post_install(config):
     """
     pass
 
+
 @hookspec
 def tljh_post_install():
     """
@@ -70,10 +75,11 @@ def tljh_post_install():
     """
     pass
 
+
 @hookspec
 def tljh_new_user_create(username):
     """
     Script to be executed after a new user has been added.
     This can be arbitrary Python code.
     """
-    pass
\ No newline at end of file
+    pass
diff --git a/tljh/installer.py b/tljh/installer.py
index a5177ef..e0ad0ec 100644
--- a/tljh/installer.py
+++ b/tljh/installer.py
@@ -73,11 +73,10 @@ def ensure_jupyterhub_service(prefix):
     with open(os.path.join(HERE, 'systemd-units', 'jupyterhub.service')) as f:
         hub_unit_template = f.read()
 
-
     with open(os.path.join(HERE, 'systemd-units', 'traefik.service')) as f:
         traefik_unit_template = f.read()
 
-    #Set up proxy / hub secret token if it is not already setup
+    # Set up proxy / hub secret token if it is not already setup
     proxy_secret_path = os.path.join(STATE_DIR, 'traefik-api.secret')
     if not os.path.exists(proxy_secret_path):
         with open(proxy_secret_path, 'w') as f:
@@ -103,7 +102,6 @@ def ensure_jupyterhub_service(prefix):
     systemd.enable_service('traefik')
 
 
-
 def ensure_jupyterhub_package(prefix):
     """
     Install JupyterHub into our conda environment if needed.
@@ -117,11 +115,7 @@ def ensure_jupyterhub_package(prefix):
     # Install pycurl. JupyterHub prefers pycurl over SimpleHTTPClient automatically
     # pycurl is generally more bugfree - see https://github.com/jupyterhub/the-littlest-jupyterhub/issues/289
     # build-essential is also generally useful to everyone involved, and required for pycurl
-    apt.install_packages([
-        'libssl-dev',
-        'libcurl4-openssl-dev',
-        'build-essential'
-    ])
+    apt.install_packages(['libssl-dev', 'libcurl4-openssl-dev', 'build-essential'])
     conda.ensure_pip_packages(prefix, ['pycurl==7.*'], upgrade=True)
 
     conda.ensure_pip_packages(
@@ -135,7 +129,7 @@ def ensure_jupyterhub_package(prefix):
             "jupyterhub-tmpauthenticator==0.6.*",
             "oauthenticator==14.*",
             "jupyterhub-idle-culler==1.*",
-            "git+https://github.com/yuvipanda/jupyterhub-configurator@317759e17c8e48de1b1352b836dac2a230536dba"
+            "git+https://github.com/yuvipanda/jupyterhub-configurator@317759e17c8e48de1b1352b836dac2a230536dba",
         ],
         upgrade=True,
     )
@@ -283,9 +277,9 @@ def ensure_jupyterhub_running(times=20):
             # Everything else should immediately abort
             raise
         except requests.ConnectionError:
-                # Hub isn't up yet, sleep & loop
-                time.sleep(1)
-                continue
+            # Hub isn't up yet, sleep & loop
+            time.sleep(1)
+            continue
         except Exception:
             # Everything else should immediately abort
             raise
@@ -312,7 +306,9 @@ def ensure_symlinks(prefix):
             #  tljh-config exists that isn't ours. We should *not* delete this file,
             # instead we throw an error and abort. Deleting files owned by other people
             # while running as root is dangerous, especially with symlinks involved.
-            raise FileExistsError(f'/usr/bin/tljh-config exists but is not a symlink to {tljh_config_src}')
+            raise FileExistsError(
+                f'/usr/bin/tljh-config exists but is not a symlink to {tljh_config_src}'
+            )
         else:
             # We have a working symlink, so do nothing
             return
@@ -343,17 +339,21 @@ def run_plugin_actions(plugin_manager):
     # Install apt packages
     apt_packages = list(set(itertools.chain(*hook.tljh_extra_apt_packages())))
     if apt_packages:
-        logger.info('Installing {} apt packages collected from plugins: {}'.format(
-            len(apt_packages), ' '.join(apt_packages)
-        ))
+        logger.info(
+            'Installing {} apt packages collected from plugins: {}'.format(
+                len(apt_packages), ' '.join(apt_packages)
+            )
+        )
         apt.install_packages(apt_packages)
 
     # Install hub pip packages
     hub_pip_packages = list(set(itertools.chain(*hook.tljh_extra_hub_pip_packages())))
     if hub_pip_packages:
-        logger.info('Installing {} hub pip packages collected from plugins: {}'.format(
-            len(hub_pip_packages), ' '.join(hub_pip_packages)
-        ))
+        logger.info(
+            'Installing {} hub pip packages collected from plugins: {}'.format(
+                len(hub_pip_packages), ' '.join(hub_pip_packages)
+            )
+        )
         conda.ensure_pip_packages(
             HUB_ENV_PREFIX,
             hub_pip_packages,
@@ -363,17 +363,21 @@ def run_plugin_actions(plugin_manager):
     # Install conda packages
     conda_packages = list(set(itertools.chain(*hook.tljh_extra_user_conda_packages())))
     if conda_packages:
-        logger.info('Installing {} user conda packages collected from plugins: {}'.format(
-            len(conda_packages), ' '.join(conda_packages)
-        ))
+        logger.info(
+            'Installing {} user conda packages collected from plugins: {}'.format(
+                len(conda_packages), ' '.join(conda_packages)
+            )
+        )
         conda.ensure_conda_packages(USER_ENV_PREFIX, conda_packages)
 
     # Install pip packages
     user_pip_packages = list(set(itertools.chain(*hook.tljh_extra_user_pip_packages())))
     if user_pip_packages:
-        logger.info('Installing {} user pip packages collected from plugins: {}'.format(
-            len(user_pip_packages), ' '.join(user_pip_packages)
-        ))
+        logger.info(
+            'Installing {} user pip packages collected from plugins: {}'.format(
+                len(user_pip_packages), ' '.join(user_pip_packages)
+            )
+        )
         conda.ensure_pip_packages(
             USER_ENV_PREFIX,
             user_pip_packages,
@@ -409,28 +413,22 @@ def ensure_config_yaml(plugin_manager):
 
 def main():
     from .log import init_logging
+
     init_logging()
 
     argparser = argparse.ArgumentParser()
     argparser.add_argument(
-        '--admin',
-        nargs='*',
-        action='append',
-        help='List of usernames set to be admin'
+        '--admin', nargs='*', action='append', help='List of usernames set to be admin'
     )
     argparser.add_argument(
         '--user-requirements-txt-url',
-        help='URL to a requirements.txt file that should be installed in the user environment'
-    )
-    argparser.add_argument(
-        '--plugin',
-        nargs='*',
-        help='Plugin pip-specs to install'
+        help='URL to a requirements.txt file that should be installed in the user environment',
     )
+    argparser.add_argument('--plugin', nargs='*', help='Plugin pip-specs to install')
     argparser.add_argument(
         '--progress-page-server-pid',
         type=int,
-        help='The pid of the progress page server'
+        help='The pid of the progress page server',
     )
 
     args = argparser.parse_args()
diff --git a/tljh/normalize.py b/tljh/normalize.py
index bba2b41..f51a4d4 100644
--- a/tljh/normalize.py
+++ b/tljh/normalize.py
@@ -10,7 +10,7 @@ def generate_system_username(username):
 
     If username < 26 char, we just return it.
     Else, we hash the username, truncate username at
-    26 char, append a '-' and first add 5char of hash. 
+    26 char, append a '-' and first add 5char of hash.
     This makes sure our usernames are always under 32char.
     """
 
@@ -19,6 +19,5 @@ def generate_system_username(username):
 
     userhash = hashlib.sha256(username.encode('utf-8')).hexdigest()
     return '{username_trunc}-{hash}'.format(
-        username_trunc=username[:26],
-        hash=userhash[:5]
-    )
\ No newline at end of file
+        username_trunc=username[:26], hash=userhash[:5]
+    )
diff --git a/tljh/systemd.py b/tljh/systemd.py
index fe85321..803c69c 100644
--- a/tljh/systemd.py
+++ b/tljh/systemd.py
@@ -13,10 +13,7 @@ def reload_daemon():
 
     Makes systemd discover new units.
     """
-    subprocess.run([
-        'systemctl',
-        'daemon-reload'
-    ], check=True)
+    subprocess.run(['systemctl', 'daemon-reload'], check=True)
 
 
 def install_unit(name, unit, path='/etc/systemd/system'):
@@ -31,43 +28,28 @@ def uninstall_unit(name, path='/etc/systemd/system'):
     """
     Uninstall unit with given name
     """
-    subprocess.run([
-        'rm',
-        os.path.join(path, name)
-    ], check=True)
+    subprocess.run(['rm', os.path.join(path, name)], check=True)
 
 
 def start_service(name):
     """
     Start service with given name.
     """
-    subprocess.run([
-        'systemctl',
-        'start',
-        name
-    ], check=True)
+    subprocess.run(['systemctl', 'start', name], check=True)
 
 
 def stop_service(name):
     """
     Start service with given name.
     """
-    subprocess.run([
-        'systemctl',
-        'stop',
-        name
-    ], check=True)
+    subprocess.run(['systemctl', 'stop', name], check=True)
 
 
 def restart_service(name):
     """
     Restart service with given name.
     """
-    subprocess.run([
-        'systemctl',
-        'restart',
-        name
-    ], check=True)
+    subprocess.run(['systemctl', 'restart', name], check=True)
 
 
 def enable_service(name):
@@ -76,11 +58,7 @@ def enable_service(name):
 
     This most likely makes the service start on bootup
     """
-    subprocess.run([
-        'systemctl',
-        'enable',
-        name
-    ], check=True)
+    subprocess.run(['systemctl', 'enable', name], check=True)
 
 
 def disable_service(name):
@@ -89,11 +67,7 @@ def disable_service(name):
 
     This most likely makes the service start on bootup
     """
-    subprocess.run([
-        'systemctl',
-        'disable',
-        name
-    ], check=True)
+    subprocess.run(['systemctl', 'disable', name], check=True)
 
 
 def check_service_active(name):
@@ -101,25 +75,18 @@ def check_service_active(name):
     Check if a service is currently active (running)
     """
     try:
-        subprocess.run([
-            'systemctl',
-            'is-active',
-            name
-        ], check=True)
+        subprocess.run(['systemctl', 'is-active', name], check=True)
         return True
     except subprocess.CalledProcessError:
         return False
 
+
 def check_service_enabled(name):
     """
     Check if a service is enabled
     """
     try:
-        subprocess.run([
-            'systemctl',
-            'is-enabled',
-            name
-        ], check=True)
+        subprocess.run(['systemctl', 'is-enabled', name], check=True)
         return True
     except subprocess.CalledProcessError:
         return False
diff --git a/tljh/traefik.py b/tljh/traefik.py
index aa4799f..6fe1533 100644
--- a/tljh/traefik.py
+++ b/tljh/traefik.py
@@ -29,6 +29,7 @@ checksums = {
     "linux-arm64": "0640fa665125efa6b598fc08c100178e24de66c5c6035ce5d75668d3dc3706e1"
 }
 
+
 def checksum_file(path):
     """Compute the sha256 checksum of a path"""
     hasher = hashlib.sha256()
@@ -37,16 +38,13 @@ def checksum_file(path):
             hasher.update(chunk)
     return hasher.hexdigest()
 
+
 def fatal_error(e):
     # Retry only when connection is reset or we think we didn't download entire file
     return str(e) != "ContentTooShort" and not isinstance(e, ConnectionResetError)
 
-@backoff.on_exception(
-    backoff.expo,
-    Exception,
-    max_tries=2,
-    giveup=fatal_error
-)
+
+@backoff.on_exception(backoff.expo, Exception, max_tries=2, giveup=fatal_error)
 def ensure_traefik_binary(prefix):
     """Download and install the traefik binary to a location identified by a prefix path such as '/opt/tljh/hub/'"""
     traefik_bin = os.path.join(prefix, "bin", "traefik")
@@ -150,4 +148,3 @@ def ensure_traefik_config(state_dir):
     # ensure acme.json exists and is private
     with open(os.path.join(state_dir, "acme.json"), "a") as f:
         os.fchmod(f.fileno(), 0o600)
-
diff --git a/tljh/user.py b/tljh/user.py
index edd2d90..2080b7c 100644
--- a/tljh/user.py
+++ b/tljh/user.py
@@ -25,17 +25,9 @@ def ensure_user(username):
         # User doesn't exist, time to create!
         pass
 
-    subprocess.check_call([
-        'useradd',
-        '--create-home',
-        username
-    ])
+    subprocess.check_call(['useradd', '--create-home', username])
 
-    subprocess.check_call([
-        'chmod',
-        'o-rwx',
-        expanduser(f'~{username}')
-    ])
+    subprocess.check_call(['chmod', 'o-rwx', expanduser(f'~{username}')])
 
     pm = get_plugin_manager()
     pm.hook.tljh_new_user_create(username=username)
@@ -51,22 +43,14 @@ def remove_user(username):
         # User doesn't exist, nothing to do
         return
 
-    subprocess.check_call([
-        'deluser',
-        '--quiet',
-        username
-    ])
+    subprocess.check_call(['deluser', '--quiet', username])
 
 
 def ensure_group(groupname):
     """
     Ensure given group exists
     """
-    subprocess.check_call([
-        'groupadd',
-        '--force',
-        groupname
-    ])
+    subprocess.check_call(['groupadd', '--force', groupname])
 
 
 def remove_group(groupname):
@@ -79,11 +63,7 @@ def remove_group(groupname):
         # Group doesn't exist, nothing to do
         return
 
-    subprocess.check_call([
-        'delgroup',
-        '--quiet',
-        groupname
-    ])
+    subprocess.check_call(['delgroup', '--quiet', groupname])
 
 
 def ensure_user_group(username, groupname):
@@ -96,12 +76,7 @@ def ensure_user_group(username, groupname):
     if username in group.gr_mem:
         return
 
-    subprocess.check_call([
-        'gpasswd',
-        '--add',
-        username,
-        groupname
-    ])
+    subprocess.check_call(['gpasswd', '--add', username, groupname])
 
 
 def remove_user_group(username, groupname):
@@ -112,9 +87,4 @@ def remove_user_group(username, groupname):
     if username not in group.gr_mem:
         return
 
-    subprocess.check_call([
-        'gpasswd',
-        '--delete',
-        username,
-        groupname
-    ])
+    subprocess.check_call(['gpasswd', '--delete', username, groupname])
diff --git a/tljh/user_creating_spawner.py b/tljh/user_creating_spawner.py
index 6490596..8fe80ce 100644
--- a/tljh/user_creating_spawner.py
+++ b/tljh/user_creating_spawner.py
@@ -5,12 +5,14 @@ from systemdspawner import SystemdSpawner
 from traitlets import Dict, Unicode, List
 from jupyterhub_configurator.mixins import ConfiguratorSpawnerMixin
 
+
 class CustomSpawner(SystemdSpawner):
     """
     SystemdSpawner with user creation on spawn.
 
     FIXME: Remove this somehow?
     """
+
     user_groups = Dict(key_trait=Unicode(), value_trait=List(Unicode()), config=True)
 
     def start(self):
@@ -34,12 +36,15 @@ class CustomSpawner(SystemdSpawner):
                     user.ensure_user_group(system_username, group)
         return super().start()
 
+
 cfg = configurer.load_config()
 # Use the jupyterhub-configurator mixin only if configurator is enabled
 # otherwise, any bugs in the configurator backend will stop new user spawns!
 if cfg['services']['configurator']['enabled']:
     # Dynamically create the Spawner class using `type`(https://docs.python.org/3/library/functions.html?#type),
     # based on whether or not it should inherit from ConfiguratorSpawnerMixin
-    UserCreatingSpawner = type('UserCreatingSpawner', (ConfiguratorSpawnerMixin, CustomSpawner), {})
+    UserCreatingSpawner = type(
+        'UserCreatingSpawner', (ConfiguratorSpawnerMixin, CustomSpawner), {}
+    )
 else:
     UserCreatingSpawner = type('UserCreatingSpawner', (CustomSpawner,), {})
diff --git a/tljh/utils.py b/tljh/utils.py
index 2b4d085..658c8ff 100644
--- a/tljh/utils.py
+++ b/tljh/utils.py
@@ -24,20 +24,26 @@ def run_subprocess(cmd, *args, **kwargs):
     and failed output directly to the user's screen
     """
     logger = logging.getLogger('tljh')
-    proc = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, *args, **kwargs)
+    proc = subprocess.run(
+        cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, *args, **kwargs
+    )
     printable_command = ' '.join(cmd)
     if proc.returncode != 0:
         # Our process failed! Show output to the user
-        logger.error('Ran {command} with exit code {code}'.format(
-            command=printable_command, code=proc.returncode
-        ))
+        logger.error(
+            'Ran {command} with exit code {code}'.format(
+                command=printable_command, code=proc.returncode
+            )
+        )
         logger.error(proc.stdout.decode())
         raise subprocess.CalledProcessError(cmd=cmd, returncode=proc.returncode)
     else:
         # This goes into installer.log
-        logger.debug('Ran {command} with exit code {code}'.format(
-            command=printable_command, code=proc.returncode
-        ))
+        logger.debug(
+            'Ran {command} with exit code {code}'.format(
+                command=printable_command, code=proc.returncode
+            )
+        )
         # This produces multi line log output, unfortunately. Not sure how to fix.
         # For now, prioritizing human readability over machine readability.
         logger.debug(proc.stdout.decode())