diff --git a/.github/workflows/docker-image.yml b/.github/workflows/docker-image.yml
index bc2c6197b..636d87059 100644
--- a/.github/workflows/docker-image.yml
+++ b/.github/workflows/docker-image.yml
@@ -9,14 +9,14 @@ jobs:
   pre-commit:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions/setup-python@v2
-    - uses: pre-commit/action@v2.0.3
+    - uses: actions/checkout@v3
+    - uses: actions/setup-python@v4
+    - uses: pre-commit/action@v3.0.0
   python-lint:
     runs-on: ubuntu-latest
     steps:
       - name: Check out pycroft and submodules
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           submodules: recursive
       - uses: actions/setup-python@v4
@@ -29,13 +29,21 @@ jobs:
         run: pip install wheel
       - name: install pip dependencies
         run: pip install -r requirements.txt -r requirements.dev.txt
+        id: pip-install
+      # now come the tests
+      - name: Execute ruff
+        run: ruff check --format=github .
+        if: success() || steps.pip-install.conclusion == 'success'
       - name: Execute mypy
         run: ./scripts/run_mypy.sh
+        if: success() || steps.pip-install.conclusion == 'success'
       # docs stuff
       - name: Build sphinx docs
         run: make SPHINXOPTS="-EN -w sphinx.log" -C doc html
+        if: success() || steps.pip-install.conclusion == 'success'
       - name: Render sphinx warnings as annotations
         run: python ./scripts/render_sphinx_log.py doc/sphinx.log
+        if: success() || steps.pip-install.conclusion == 'success'
       - name: Publish sphinx docs as pages artifact
         uses: actions/upload-pages-artifact@v1
         with:
@@ -63,7 +71,7 @@ jobs:
   npm-build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: actions/setup-node@v3
       with:
         node-version: 16
@@ -77,7 +85,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
            submodules: 'true'
       - name: Fix permissions
@@ -98,7 +106,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
            submodules: 'true'
       - name: Fix permissions
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 9bc5b3be1..bd4439985 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,13 +1,22 @@
 # see https://github.com/topics/pre-commit-hook for more
 repos:
+-   repo: https://github.com/akaihola/darker
+    rev: 1.6.1
+    hooks:
+    -   id: darker
 -   repo: https://github.com/asottile/pyupgrade
     rev: v2.29.0
     hooks:
     -   id: pyupgrade
         args: ["--py310-plus"]
+- repo: https://github.com/charliermarsh/ruff-pre-commit
+  # Ruff version.
+  rev: 'v0.0.241'
+  hooks:
+    - id: ruff
 - repo: https://github.com/returntocorp/semgrep
   rev: 'v0.91.0'
   hooks:
   - id: semgrep
     # See semgrep.dev/rulesets to select a ruleset and copy its URL
-    args: ['--config', 'tools/semgrep.yml', '--metrics=off', '--error', '--skip-unknown-extensions']    
+    args: ['--config', 'tools/semgrep.yml', '--metrics=off', '--error', '--skip-unknown-extensions']
diff --git a/hades_logs/__init__.py b/hades_logs/__init__.py
index 260e82490..8b353da19 100644
--- a/hades_logs/__init__.py
+++ b/hades_logs/__init__.py
@@ -159,7 +159,9 @@ def _get_extension():
     try:
         return current_app.extensions['hades_logs']
     except KeyError:
-        raise HadesConfigError("No HadesLogs instance registered to current Flask app")
+        raise HadesConfigError(
+            "No HadesLogs instance registered to current Flask app"
+        ) from None
 
-hades_logs: HadesLogs = LocalProxy(_get_extension)
 
+hades_logs: HadesLogs = LocalProxy(_get_extension)
diff --git a/hades_logs/parsing.py b/hades_logs/parsing.py
index 5ded24cb7..73c6aeabc 100644
--- a/hades_logs/parsing.py
+++ b/hades_logs/parsing.py
@@ -18,8 +18,10 @@ def parse_vlan(vlan):
         raise ParsingError(f"VLAN identifier has no Name: {name}")
     try:
         taggedness = {'1': "tagged", '2': "untagged"}[prefix]
-    except KeyError:
-        raise ParsingError(f"VLAN identifier must start with '1' or '2': {stripped}")
+    except KeyError as e:
+        raise ParsingError(
+            f"VLAN identifier must start with '1' or '2': {stripped}"
+        ) from e
     return f"{name} ({taggedness})"
 
 
diff --git a/helpers/interactive.py b/helpers/interactive.py
index aebfc6c4d..1fced664e 100644
--- a/helpers/interactive.py
+++ b/helpers/interactive.py
@@ -15,7 +15,6 @@
 
 """
 import logging
-import os
 
 from flask import _request_ctx_stack
 from sqlalchemy.orm import scoped_session, sessionmaker
@@ -24,7 +23,6 @@
 from scripts.connection import try_create_connection, get_connection_string
 
 from pycroft.model._all import *
-from pycroft import config
 
 connection_string = get_connection_string()
 
diff --git a/ldap_sync/concepts/record.py b/ldap_sync/concepts/record.py
index 8a609913d..a88003712 100644
--- a/ldap_sync/concepts/record.py
+++ b/ldap_sync/concepts/record.py
@@ -8,7 +8,6 @@
 
 from __future__ import annotations
 
-import abc
 import dataclasses
 import typing
 
diff --git a/ldap_sync/sources/db.py b/ldap_sync/sources/db.py
index dcbd7984e..752be4ded 100644
--- a/ldap_sync/sources/db.py
+++ b/ldap_sync/sources/db.py
@@ -16,7 +16,7 @@
 import typing
 from typing import NamedTuple
 
-from sqlalchemy import and_, func, select, join, text, literal
+from sqlalchemy import and_, func, select, join, literal
 from sqlalchemy.dialects import postgresql
 from sqlalchemy.orm import scoped_session, sessionmaker, joinedload, foreign, Session
 
diff --git a/ldap_sync/sources/ldap.py b/ldap_sync/sources/ldap.py
index 714aa4ef2..ab4df2d2a 100644
--- a/ldap_sync/sources/ldap.py
+++ b/ldap_sync/sources/ldap.py
@@ -14,7 +14,6 @@
 from ..concepts.record import UserRecord, GroupRecord
 from ..config import SyncConfig
 from ..concepts.types import LdapRecord
-from ..conversion import ldap_user_to_record, ldap_group_to_record
 
 
 def establish_and_return_ldap_connection(config: SyncConfig) -> ldap3.Connection:
diff --git a/pycroft/helpers/i18n/babel.py b/pycroft/helpers/i18n/babel.py
index 8cfefc3b6..027089ce0 100644
--- a/pycroft/helpers/i18n/babel.py
+++ b/pycroft/helpers/i18n/babel.py
@@ -15,8 +15,14 @@
 
 _unspecified_locale = Locale("en", "US")
 _null_translations = Translations()
-_locale_lookup: typing.Callable[[], Locale] = lambda: _unspecified_locale
-_translations_lookup: typing.Callable[[], Translations] = lambda: _null_translations
+
+
+def _locale_lookup() -> Locale:
+    return _unspecified_locale
+
+
+def _translations_lookup() -> Translations:
+    return _null_translations
 
 
 def get_locale() -> Locale:
diff --git a/pycroft/helpers/i18n/formatting.py b/pycroft/helpers/i18n/formatting.py
index 1816f3e9a..d7f1577c5 100644
--- a/pycroft/helpers/i18n/formatting.py
+++ b/pycroft/helpers/i18n/formatting.py
@@ -165,7 +165,7 @@ def format_param(p, options: dict[type, dict[str, typing.Any]]) -> Formattable:
         raise TypeError(
             f"No formatter available for type {qualified_typename(concrete_type)}"
             " or any supertype."
-        )
+        ) from None
     option_policy: OptionPolicy | None = getattr(formatter, "__option_policy__", None)
     if option_policy == "ignore":
         formatter_options: dict[str, typing.Any] = {}
diff --git a/pycroft/helpers/i18n/serde.py b/pycroft/helpers/i18n/serde.py
index 9e637a52f..fe8d607fd 100644
--- a/pycroft/helpers/i18n/serde.py
+++ b/pycroft/helpers/i18n/serde.py
@@ -23,8 +23,8 @@ def identity(x):
 def deserialize_money(v):
     try:
         return Money(Decimal(v[0]), v[1])
-    except IndexError:
-        raise ValueError()
+    except IndexError as e:
+        raise ValueError from e
 
 
 def serialize_interval(interval: Interval) -> dict[str, typing.Any]:
@@ -147,7 +147,7 @@ def serialize_param(param):
         raise TypeError(
             "No serialization available for type {} or any"
             "supertype".format(qualified_typename(concrete_type))
-        )
+        ) from None
     return {"type": qualified_typename(type_), "value": serializer(param)}
 
 
@@ -156,5 +156,5 @@ def deserialize_param(param):
     try:
         deserializer = deserialize_map[type_name]
     except KeyError:
-        raise TypeError(f"No deserialization available for type {type_name}")
+        raise TypeError(f"No deserialization available for type {type_name}") from None
     return deserializer(param["value"])
diff --git a/pycroft/helpers/interval.py b/pycroft/helpers/interval.py
index 89b21e0ff..1bd1eecc7 100644
--- a/pycroft/helpers/interval.py
+++ b/pycroft/helpers/interval.py
@@ -727,7 +727,7 @@ def _complement(intervals: t.Iterable[Interval[T]]) -> t.Iterator[Interval[T]]:
         yield Interval(Bound(NegativeInfinity, False), ~first.lower_bound)
     a, b = tee(intervals)
     last = first
-    for current_, next_ in zip(chain((first,), a), b):
+    for current_, next_ in zip(chain((first,), a), b, strict=False):
         yield Interval(~current_.upper_bound, ~next_.lower_bound)
         last = next_
     if not last.upper_bound.unbounded:
diff --git a/pycroft/helpers/printing/__init__.py b/pycroft/helpers/printing/__init__.py
index ef00ee9e4..431555ccf 100644
--- a/pycroft/helpers/printing/__init__.py
+++ b/pycroft/helpers/printing/__init__.py
@@ -135,8 +135,10 @@ def generate_user_sheet(
     style = getStyleSheet()
     story = []
 
-    PAGE_WIDTH = defaultPageSize[0]
-    PAGE_HEIGHT = defaultPageSize[1]
+    # noinspection Ruff
+    defaultPageSize[0]
+    # noinspection Ruff
+    defaultPageSize[1]
 
     # HEADER
     im_web = Image(ASSETS_WEB_FILENAME, 0.4 * cm, 0.4 * cm)
diff --git a/pycroft/lib/facilities.py b/pycroft/lib/facilities.py
index ec9dee830..d71012e65 100644
--- a/pycroft/lib/facilities.py
+++ b/pycroft/lib/facilities.py
@@ -5,7 +5,6 @@
 import logging
 import re
 import typing as t
-from collections import defaultdict
 from dataclasses import dataclass
 from itertools import groupby
 
diff --git a/pycroft/lib/finance.py b/pycroft/lib/finance.py
index 256dc5c70..44bfb58f9 100644
--- a/pycroft/lib/finance.py
+++ b/pycroft/lib/finance.py
@@ -23,7 +23,6 @@
     text, future
 from sqlalchemy.orm import aliased, contains_eager, joinedload, Session, Query
 from sqlalchemy.orm.exc import NoResultFound
-from sqlalchemy.sql import Select
 
 from pycroft import config
 from pycroft.helpers.date import diff_month, last_day_of_month
@@ -162,7 +161,7 @@ def complex_transaction(
 def transferred_amount(
     from_account: Account,
     to_account: Account,
-    when: Interval[date] = t.cast(Interval[date], UnboundedInterval),
+    when: Interval[date] = t.cast(Interval[date], UnboundedInterval),  # noqa: B008
 ) -> Decimal:
     """
     Determine how much has been transferred from one account to another in a
@@ -472,7 +471,7 @@ def is_ordered(
     except StopIteration:
         # iterable is empty
         return True
-    return all(relation(x, y) for x, y in zip(a, b))
+    return all(relation(x, y) for x, y in zip(a, b, strict=False))
 
 
 @with_transaction
@@ -506,9 +505,9 @@ def import_bank_account_activities_csv(
             process_record(index, record, imported_at=imported_at)
             for index, record in records)
     except StopIteration:
-        raise CSVImportError(gettext("No data present."))
+        raise CSVImportError(gettext("No data present.")) from None
     except csv.Error as e:
-        raise CSVImportError(gettext("Could not read CSV."), e)
+        raise CSVImportError(gettext("Could not read CSV."), e) from e
     if not activities:
         raise CSVImportError(gettext("No data present."))
     if not is_ordered((a[8] for a in activities), operator.ge):
@@ -617,7 +616,8 @@ def process_record(
                           "Record {1}: {2}")
         raw_record = restore_record(record)
         raise CSVImportError(
-            message.format(record.our_account_number, index, raw_record), e)
+            message.format(record.our_account_number, index, raw_record), e
+        ) from None
 
     try:
         valid_on = datetime.strptime(record.valid_on, "%d.%m.%y").date()
@@ -625,15 +625,14 @@ def process_record(
     except ValueError as e:
         message = gettext("Illegal date format. Record {1}: {2}")
         raw_record = restore_record(record)
-        raise CSVImportError(message.format(index, raw_record), e)
+        raise CSVImportError(message.format(index, raw_record), e) from e
 
     try:
         amount = Decimal(record.amount.replace(",", "."))
     except ValueError as e:
         message = gettext("Illegal value format {0}. Record {1}: {2}")
         raw_record = restore_record(record)
-        raise CSVImportError(
-            message.format(record.amount, index, raw_record), e)
+        raise CSVImportError(message.format(record.amount, index, raw_record), e) from e
 
     return (amount, bank_account.id, cleanup_description(record.reference),
             record.reference, record.other_account_number,
@@ -897,7 +896,7 @@ def build_transactions_query(
     ):
         sort_by = "valid_on"
 
-    descending = (sort_order == "desc") ^ (positive == False)
+    descending = (sort_order == "desc") ^ (positive is False)
     ordering = sort_by + " desc" if descending else sort_by
     if search:
         query = query.filter(Transaction.description.ilike(f'%{search}%'))
diff --git a/pycroft/lib/mail.py b/pycroft/lib/mail.py
index ea7d70233..03c54cc42 100644
--- a/pycroft/lib/mail.py
+++ b/pycroft/lib/mail.py
@@ -122,7 +122,7 @@ def send_mails(mails: list[Mail]) -> tuple[bool, int]:
                 'trace': True,
                 'data': {'exception_arguments': e.args}
             })
-            raise RetryableException
+            raise RetryableException from e
 
     try:
         smtp: smtplib.SMTP
@@ -143,13 +143,17 @@ def send_mails(mails: list[Mail]) -> tuple[bool, int]:
         traceback.print_exc()
 
         # smtp.connect failed to connect
-        logger.critical(f'Unable to connect to SMTP server: %s', e, extra={
-            'trace': True,
-            'tags': {'mailserver': f"{smtp_host}:{smtp_host}"},
-            'data': {'exception_arguments': e.args}
-        })
-
-        raise RetryableException
+        logger.critical(
+            "Unable to connect to SMTP server: %s",
+            e,
+            extra={
+                "trace": True,
+                "tags": {"mailserver": f"{smtp_host}:{smtp_host}"},
+                "data": {"exception_arguments": e.args},
+            },
+        )
+
+        raise RetryableException from e
     else:
         failures: int = 0
 
diff --git a/pycroft/lib/membership.py b/pycroft/lib/membership.py
index 265139cfa..4564c4827 100644
--- a/pycroft/lib/membership.py
+++ b/pycroft/lib/membership.py
@@ -75,7 +75,9 @@ def make_member_of(
     user: User,
     group: PropertyGroup,
     processor: User,
-    during: Interval[DateTimeTz] = t.cast(Interval[DateTimeTz], UnboundedInterval),
+    during: Interval[DateTimeTz] = t.cast(  # noqa: B008
+        Interval[DateTimeTz], UnboundedInterval
+    ),
 ) -> None:
     """Makes a user member of a group in a given interval.
 
@@ -116,7 +118,9 @@ def remove_member_of(
     user: User,
     group: PropertyGroup,
     processor: User,
-    during: Interval[DateTimeTz] = t.cast(Interval[DateTimeTz], UnboundedInterval),
+    during: Interval[DateTimeTz] = t.cast(  # noqa: B008
+        Interval[DateTimeTz], UnboundedInterval
+    ),
 ) -> None:
     """Remove a user from a group in a given interval.
 
@@ -185,18 +189,15 @@ def user_memberships_query(user_id: int, active_groups_only: bool = False) -> Qu
     p_granted = aliased(Property)
     p_denied = aliased(Property)
     memberships = (
-        memberships
-            .join(group)
-            .outerjoin(p_granted, and_(p_granted.property_group_id == group.id,
-                                       p_granted.granted == True))
-            .add_column(func.array_agg(distinct(p_granted.name))
-                        .label('granted'))
-
-            .outerjoin(p_denied, and_(p_denied.property_group_id == group.id,
-                                      p_denied.granted == False))
-            .add_column(func.array_agg(distinct(p_denied.name))
-                        .label('denied'))
-
-            .group_by(Membership.id)
+        memberships.join(group)
+        .outerjoin(
+            p_granted, and_(p_granted.property_group_id == group.id, p_granted.granted)
+        )
+        .add_column(func.array_agg(distinct(p_granted.name)).label("granted"))
+        .outerjoin(
+            p_denied, and_(p_denied.property_group_id == group.id, ~p_denied.granted)
+        )
+        .add_column(func.array_agg(distinct(p_denied.name)).label("denied"))
+        .group_by(Membership.id)
     )
     return memberships
diff --git a/pycroft/lib/task.py b/pycroft/lib/task.py
index a593157fe..162f193d2 100644
--- a/pycroft/lib/task.py
+++ b/pycroft/lib/task.py
@@ -11,10 +11,10 @@
 
 from marshmallow import ValidationError
 from sqlalchemy import select
-from sqlalchemy.orm import with_polymorphic, Session
+from sqlalchemy.orm import with_polymorphic
 
 from pycroft.helpers.i18n import deferred_gettext
-from pycroft.helpers.utc import DateTimeTz, with_min_time, ensure_tz
+from pycroft.helpers.utc import DateTimeTz, ensure_tz
 from pycroft.lib.logging import log_task_event
 from pycroft.model import session
 from pycroft.model.session import with_transaction
diff --git a/pycroft/lib/user.py b/pycroft/lib/user.py
index a0a263885..5fbb44665 100644
--- a/pycroft/lib/user.py
+++ b/pycroft/lib/user.py
@@ -13,12 +13,11 @@
 import re
 import typing
 import typing as t
-from datetime import datetime, timedelta, date
+from datetime import timedelta, date
 from difflib import SequenceMatcher
 from typing import Iterable
 
 from sqlalchemy import func, select, Boolean, String
-from sqlalchemy.engine import Row
 
 from pycroft import config, property
 from pycroft.helpers import user as user_helper, utc
@@ -829,7 +828,7 @@ def move_out(
 
     deleted_interfaces = list()
     num_hosts = 0
-    for num_hosts, h in enumerate(user.hosts, 1):
+    for num_hosts, h in enumerate(user.hosts, 1):  # noqa: B007
         if not h.switch and (h.room == user.room or end_membership):
             for interface in h.interfaces:
                 deleted_interfaces.append(interface.mac)
@@ -843,7 +842,6 @@ def move_out(
             .format(room=user.room.short_name,
                     num_hosts=num_hosts,
                     interfaces=', '.join(deleted_interfaces))
-        had_custom_address = user.has_custom_address
         user.room = None
     elif num_hosts:
         message = "Deleted interfaces {interfaces} of {num_hosts} hosts." \
@@ -947,7 +945,6 @@ def membership_ending_task(user: User) -> UserTask:
         # Casting jsonb -> bool directly is only supported since PG v11
         .filter(
             UserTask.parameters_json["end_membership"].cast(String).cast(Boolean)
-            == True
         )
         .order_by(UserTask.due.asc())
         .first(),
@@ -977,7 +974,7 @@ def membership_beginning_task(user: User) -> UserTask:
         UserTask.q.filter_by(
             user_id=user.id, status=TaskStatus.OPEN, type=TaskType.USER_MOVE_IN
         )
-        .filter(UserTask.parameters_json["begin_membership"].cast(Boolean) == True)
+        .filter(UserTask.parameters_json["begin_membership"].cast(Boolean))
         .order_by(UserTask.due.asc())
         .first(),
     )
diff --git a/pycroft/lib/user_deletion.py b/pycroft/lib/user_deletion.py
index 5da80a9be..bf831f9dd 100644
--- a/pycroft/lib/user_deletion.py
+++ b/pycroft/lib/user_deletion.py
@@ -11,7 +11,6 @@
 from sqlalchemy import func, nulls_last, and_, not_
 from sqlalchemy.future import select
 from sqlalchemy.orm import joinedload, Session
-from sqlalchemy.sql.elements import ClauseElement
 from sqlalchemy.sql.functions import current_timestamp
 
 from pycroft import Config
diff --git a/pycroft/model/alembic/env.py b/pycroft/model/alembic/env.py
index c93bc5392..a189d772a 100644
--- a/pycroft/model/alembic/env.py
+++ b/pycroft/model/alembic/env.py
@@ -1,6 +1,6 @@
 import os
 from alembic import context
-from sqlalchemy import engine_from_config, pool, create_engine
+from sqlalchemy import create_engine
 from logging.config import fileConfig
 
 # this is the Alembic Config object, which provides
@@ -9,7 +9,7 @@
 try:
     uri = os.environ['PYCROFT_DB_URI']
 except KeyError:
-    raise ValueError("Please Provide a valid uri in `PYCROFT_DB_URI`.")
+    raise ValueError("Please Provide a valid uri in `PYCROFT_DB_URI`.") from None
 engine = create_engine(uri)
 
 # Interpret the config file for Python logging.
@@ -18,7 +18,7 @@
 
 # add your model's MetaData object here
 # for 'autogenerate' support
-from pycroft.model.base import ModelBase
+from pycroft.model.base import ModelBase  # noqa: E402
 target_metadata = ModelBase.metadata
 
 # other values from the config, defined by the needs of env.py,
diff --git a/pycroft/model/alembic/versions/20234ac06668_use_tstzrange_for_room_history_entry.py b/pycroft/model/alembic/versions/20234ac06668_use_tstzrange_for_room_history_entry.py
index 17affafd5..b2897872e 100644
--- a/pycroft/model/alembic/versions/20234ac06668_use_tstzrange_for_room_history_entry.py
+++ b/pycroft/model/alembic/versions/20234ac06668_use_tstzrange_for_room_history_entry.py
@@ -69,7 +69,7 @@ def upgrade():
     ###
 
     # -UNIQUENESS CHECK
-    op.execute(f'drop function room_history_entry_uniqueness cascade')
+    op.execute("drop function room_history_entry_uniqueness cascade")
     # also deletes the trigger
     ###
 
diff --git a/pycroft/model/alembic/versions/249743eb7b94_add_hostname_column_to_dhcphost_view.py b/pycroft/model/alembic/versions/249743eb7b94_add_hostname_column_to_dhcphost_view.py
index afcf258a5..2ae4cbdbf 100644
--- a/pycroft/model/alembic/versions/249743eb7b94_add_hostname_column_to_dhcphost_view.py
+++ b/pycroft/model/alembic/versions/249743eb7b94_add_hostname_column_to_dhcphost_view.py
@@ -6,7 +6,6 @@
 
 """
 from alembic import op
-import sqlalchemy as sa
 
 
 # revision identifiers, used by Alembic.
@@ -18,28 +17,28 @@
 
 def upgrade():
     op.execute("""
-		CREATE OR REPLACE VIEW dhcphost AS
-		 SELECT interface.mac AS "Mac",
-			host(ip.address) AS "IpAddress",
-			host.name AS "Hostname"
-		   FROM "user"
-			 JOIN current_property ON "user".id = current_property.user_id AND NOT current_property.denied
-			 JOIN host ON "user".id = host.owner_id
-			 JOIN interface ON host.id = interface.host_id
-			 JOIN ip ON interface.id = ip.interface_id
-		  WHERE current_property.property_name::text = 'network_access'::text
+        CREATE OR REPLACE VIEW dhcphost AS
+         SELECT interface.mac AS "Mac",
+            host(ip.address) AS "IpAddress",
+            host.name AS "Hostname"
+           FROM "user"
+             JOIN current_property ON "user".id = current_property.user_id AND NOT current_property.denied
+             JOIN host ON "user".id = host.owner_id
+             JOIN interface ON host.id = interface.host_id
+             JOIN ip ON interface.id = ip.interface_id
+          WHERE current_property.property_name::text = 'network_access'::text
     """)
 
 
 def downgrade():
     op.execute("""
-		CREATE OR REPLACE VIEW dhcphost AS
-		 SELECT interface.mac AS "Mac",
-			host(ip.address) AS "IpAddress"
-		   FROM "user"
-			 JOIN current_property ON "user".id = current_property.user_id AND NOT current_property.denied
-			 JOIN host ON "user".id = host.owner_id
-			 JOIN interface ON host.id = interface.host_id
-			 JOIN ip ON interface.id = ip.interface_id
-		  WHERE current_property.property_name::text = 'network_access'::text
+        CREATE OR REPLACE VIEW dhcphost AS
+         SELECT interface.mac AS "Mac",
+            host(ip.address) AS "IpAddress"
+           FROM "user"
+             JOIN current_property ON "user".id = current_property.user_id AND NOT current_property.denied
+             JOIN host ON "user".id = host.owner_id
+             JOIN interface ON host.id = interface.host_id
+             JOIN ip ON interface.id = ip.interface_id
+          WHERE current_property.property_name::text = 'network_access'::text
     """)
diff --git a/pycroft/model/base.py b/pycroft/model/base.py
index 4cf6e2c5b..dd92734dc 100644
--- a/pycroft/model/base.py
+++ b/pycroft/model/base.py
@@ -10,7 +10,6 @@
     :copyright: (c) 2011 by AG DSN.
 """
 import re
-import typing as t
 
 import ipaddr
 from sqlalchemy import String
@@ -105,7 +104,7 @@ def __str__(self):
         T = typing.TypeVar('T', bound='ModelBase')
 
         @classmethod
-        def get(cls: type[T], *a, **kw) -> T:
+        def get(cls: type[T], *a, **kw) -> T:  # noqa: F811
             pass
 
 
diff --git a/pycroft/model/ddl.py b/pycroft/model/ddl.py
index 8edb3f2bd..ae9b34690 100644
--- a/pycroft/model/ddl.py
+++ b/pycroft/model/ddl.py
@@ -560,7 +560,7 @@ def add_view(self, table, view, dialect=None, or_replace=True, if_not_exists=Tru
                  DropView(view, if_exists=True), dialect=dialect)
 
     def register(self):
-        for target, create_ddl, drop_ddl in self.objects:
+        for target, create_ddl, _drop_ddl in self.objects:
             sqla_event.listen(target, 'after_create', create_ddl)
-        for target, create_ddl, drop_ddl in reversed(self.objects):
+        for target, _create_ddl, drop_ddl in reversed(self.objects):
             sqla_event.listen(target, 'before_drop', drop_ddl)
diff --git a/pycroft/model/facilities.py b/pycroft/model/facilities.py
index efbb31424..98089c40e 100644
--- a/pycroft/model/facilities.py
+++ b/pycroft/model/facilities.py
@@ -78,7 +78,7 @@ class Room(IntegerIdModel):
     swdd_vo_suchname: Mapped[str | None]
 
     connected_patch_ports: Mapped[list[PatchPort]] = relationship(
-        primaryjoin='and_(PatchPort.room_id == Room.id, PatchPort.switch_port_id != None)',
+        primaryjoin='and_(PatchPort.room_id == Room.id, PatchPort.switch_port_id.is_not(None))',
         viewonly=True,
     )
 
diff --git a/pycroft/model/finance.py b/pycroft/model/finance.py
index 45f321bf9..dd7b7534d 100644
--- a/pycroft/model/finance.py
+++ b/pycroft/model/finance.py
@@ -20,7 +20,7 @@
 from pycroft.helpers.i18n import gettext
 from pycroft.helpers.interval import closed
 from pycroft.model import ddl
-from pycroft.model.types import Money, DateTimeTz
+from pycroft.model.types import Money
 from .base import IntegerIdModel
 from .exc import PycroftModelException
 from .type_aliases import str127, str255, datetime_tz_onupdate
diff --git a/pycroft/model/hades.py b/pycroft/model/hades.py
index c47af92ab..db78d00a9 100644
--- a/pycroft/model/hades.py
+++ b/pycroft/model/hades.py
@@ -106,7 +106,7 @@
             literal(0).label('Priority'),
         ]).select_from(User)
         .outerjoin(network_access_subq, User.id == network_access_subq.c.user_id)
-        .filter(network_access_subq.c.network_access == None)
+        .filter(network_access_subq.c.network_access.is_(None))
         .join(User.hosts)
         .join(Host.interfaces)
         .join(Host.room)
diff --git a/pycroft/model/task.py b/pycroft/model/task.py
index 416028a78..1453a09ec 100644
--- a/pycroft/model/task.py
+++ b/pycroft/model/task.py
@@ -16,7 +16,6 @@
 from typing import TypeVar, Generic
 
 from pycroft.model.base import IntegerIdModel
-from pycroft.model.types import DateTimeTz
 from .task_serialization import UserMoveOutSchema, UserMoveSchema, UserMoveInSchema, TaskParams
 from .type_aliases import str50
 from ..helpers import utc
diff --git a/pycroft/model/traffic.py b/pycroft/model/traffic.py
index ed362663d..eeb473aac 100644
--- a/pycroft/model/traffic.py
+++ b/pycroft/model/traffic.py
@@ -5,7 +5,6 @@
 pycroft.model.traffic
 ~~~~~~~~~~~~~~~~~~~~~
 """
-import enum
 import typing as t
 
 from sqlalchemy import (
@@ -195,9 +194,9 @@ def traffic_history_query():
               ).cte()
 
     events_ingress = select(events).where(
-        or_(events.c.type == 'Ingress', events.c.type == None)).cte()
+        or_(events.c.type == 'Ingress', events.c.type.is_(None))).cte()
     events_egress = select(events).where(
-        or_(events.c.type == 'Egress', events.c.type == None)).cte()
+        or_(events.c.type == 'Egress', events.c.type.is_(None))).cte()
 
     hist = (select(func.coalesce(events_ingress.c.day, events_egress.c.day).label('timestamp'),
                    events_ingress.c.amount.label('ingress'),
diff --git a/pycroft/model/user.py b/pycroft/model/user.py
index b69f862b5..acaa98f0f 100644
--- a/pycroft/model/user.py
+++ b/pycroft/model/user.py
@@ -58,7 +58,7 @@
 from pycroft.model.base import ModelBase, IntegerIdModel
 from pycroft.model.exc import PycroftModelException
 from pycroft.model.facilities import Room
-from pycroft.model.types import DateTimeTz, TsTzRange
+from pycroft.model.types import TsTzRange
 from .type_aliases import str255, str40
 
 if t.TYPE_CHECKING:
diff --git a/pycroft/model/webstorage.py b/pycroft/model/webstorage.py
index ae91d9716..293d788f2 100644
--- a/pycroft/model/webstorage.py
+++ b/pycroft/model/webstorage.py
@@ -11,7 +11,6 @@
 from pycroft.helpers import utc
 from pycroft.model.base import IntegerIdModel
 from pycroft.model.session import session
-from pycroft.model.types import DateTimeTz
 
 
 class WebStorage(IntegerIdModel):
diff --git a/pycroft/task.py b/pycroft/task.py
index 89d77b680..f4aafba9a 100644
--- a/pycroft/task.py
+++ b/pycroft/task.py
@@ -102,7 +102,7 @@ def __init__(self) -> None:
             raise RuntimeError(
                 "Environment variable PYCROFT_DB_URI must be "
                 "set to an SQLAlchemy connection string."
-            )
+            ) from None
 
         self.connection, self.engine = try_create_connection(
             connection_string, 5, logger=logging.getLogger("tasks"), echo=False
diff --git a/pyproject.toml b/pyproject.toml
index 2010e281a..0b2a9fa2f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -62,3 +62,41 @@ filterwarnings = [
     "ignore:.*load_module.*:DeprecationWarning:importlib._bootstrap",
 ]
 timeout = "10"
+
+[tool.ruff]
+line-length = 100
+target-version = "py310"
+exclude = [
+    "deps/",
+    "doc/",
+    # match statement cannot be parsed yet… :/
+    # see https://github.com/charliermarsh/ruff/issues/282
+
+    "ldap_sync/record_diff.py",
+    "web/blueprints/helpers/exception.py",
+]
+# to look up the meaning of specific rule IDs, use `ruff rule $id`
+select = [
+    "E",
+    "F",
+    "B",  # flake8-bugbear
+]
+ignore = [
+    "E741",  # ambiguous variable names
+    "E501",  # line length violations (for now)
+]
+unfixable = [
+    "B",  # fixing bug hazards requires knowledge about the intention
+
+    # We don't want to autofix these: when using `== True|False|None`
+    # in a sqlalchemy expression, the `is` would actually _not_ be correct!
+    # the correct workaround is to use the `.is_` / `.is_not` functions
+    # (or, in the case of bools, don't do a comparison at all or use negation)
+    "E711",  # comparison to None
+    "E712",  # comparison to True/False
+]
+
+[tool.ruff.per-file-ignores]
+"__init__.py" = ["E402", "F401"]
+"pycroft/model/_all.py" = ["F403"]
+"helpers/interactive.py" = ["F403"]
diff --git a/requirements.dev.txt b/requirements.dev.txt
index 511206c7b..e49841438 100644
--- a/requirements.dev.txt
+++ b/requirements.dev.txt
@@ -18,3 +18,4 @@ types-passlib~=1.7.7
 sphinx-paramlinks~=0.5.4
 sphinxcontrib-fulltoc~=1.2.0
 sphinxcontrib-httpdomain~=1.8.0
+ruff~=0.0.241
diff --git a/scripts/connection.py b/scripts/connection.py
index bf7289029..013078ab0 100644
--- a/scripts/connection.py
+++ b/scripts/connection.py
@@ -42,6 +42,8 @@ def get_connection_string():
     try:
         connection_string = os.environ['PYCROFT_DB_URI']
     except KeyError:
-        raise RuntimeError("Environment variable PYCROFT_DB_URI must be "
-                           "set to an SQLAlchemy connection string.")
+        raise RuntimeError(
+            "Environment variable PYCROFT_DB_URI must be "
+            "set to an SQLAlchemy connection string."
+        ) from None
     return connection_string
diff --git a/scripts/render_outdated.py b/scripts/render_outdated.py
index ab9a38a61..3d92c2370 100755
--- a/scripts/render_outdated.py
+++ b/scripts/render_outdated.py
@@ -14,7 +14,7 @@ def md_row(*items: str) -> str:
 
     COLS = "current wanted latest dependent".split()  # don't care about location
     if not j:
-        print(f"### :white_check_mark: All NPM packages up-to-date")
+        print("### :white_check_mark: All NPM packages up-to-date")
         exit(0)
     print(f"### :warning: {len(j)} Outdated NPM packages")
     print()
diff --git a/scripts/server_run.py b/scripts/server_run.py
index d98064487..233337e3d 100755
--- a/scripts/server_run.py
+++ b/scripts/server_run.py
@@ -15,7 +15,6 @@
 from sqlalchemy.orm import scoped_session, sessionmaker
 from werkzeug.middleware.profiler import ProfilerMiddleware
 
-import ldap_sync
 import pycroft
 import web
 from pycroft.helpers.i18n import set_translation_lookup, get_locale
diff --git a/tests/conftest.py b/tests/conftest.py
index 65be8ab84..7175d063f 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -20,8 +20,10 @@ def engine():
     try:
         uri = os.environ['PYCROFT_DB_URI']
     except KeyError:
-        raise RuntimeError("Environment variable PYCROFT_DB_URI must be "
-                           "set to an SQLalchemy connection string.")
+        raise RuntimeError(
+            "Environment variable PYCROFT_DB_URI must be "
+            "set to an SQLalchemy connection string."
+        ) from None
     return create_engine(uri, poolclass=SingletonThreadPool, future=True)
 
 
diff --git a/tests/factories/user.py b/tests/factories/user.py
index 474595891..bdfffcc76 100644
--- a/tests/factories/user.py
+++ b/tests/factories/user.py
@@ -1,7 +1,6 @@
 # Copyright (c) 2016 The Pycroft Authors. See the AUTHORS file.
 # This file is part of the Pycroft project and licensed under the terms of
 # the Apache License, Version 2.0. See the LICENSE file for details.
-import warnings
 
 import factory
 from factory.faker import Faker
diff --git a/tests/frontend/conftest.py b/tests/frontend/conftest.py
index bf0a7bcc7..b903077dd 100644
--- a/tests/frontend/conftest.py
+++ b/tests/frontend/conftest.py
@@ -8,7 +8,7 @@
 from pycroft import Config
 from pycroft.model.user import User, PropertyGroup
 from tests.factories import UserFactory, AdminPropertyGroupFactory, ConfigFactory
-from web import make_app, PycroftFlask
+from web import PycroftFlask
 from .assertions import TestClient
 from .fixture_helpers import login_context, BlueprintUrls, _build_rule, prepare_app_for_testing
 from ..factories.property import FinancePropertyGroupFactory, MembershipFactory
diff --git a/tests/frontend/fixture_helpers.py b/tests/frontend/fixture_helpers.py
index 577038cd3..e9d1718f3 100644
--- a/tests/frontend/fixture_helpers.py
+++ b/tests/frontend/fixture_helpers.py
@@ -44,7 +44,7 @@ def _build_rule(url_adapter, rule) -> str:
             for k, v in rule._converters.items()
         }
     except KeyError as e:
-        raise AssertionError(f"Cannot create mock argument for {e.args[0]}")
+        raise AssertionError(f"Cannot create mock argument for {e.args[0]}") from e
     return url_adapter.build(rule.endpoint, values, 'GET')
 
 
diff --git a/tests/frontend/test_permissions.py b/tests/frontend/test_permissions.py
index beaa0ad9f..8904c9a89 100644
--- a/tests/frontend/test_permissions.py
+++ b/tests/frontend/test_permissions.py
@@ -6,9 +6,8 @@
 from sqlalchemy.orm import Session
 
 from pycroft.model.config import Config
-from pycroft.model.user import PropertyGroup, User
-from tests.factories.property import FinancePropertyGroupFactory, \
-    AdminPropertyGroupFactory, MembershipFactory
+from pycroft.model.user import User
+from tests.factories.property import AdminPropertyGroupFactory
 from tests.factories.user import UserFactory
 from web import PycroftFlask
 from web.template_filters import require
diff --git a/tests/helpers/interval/test_interval.py b/tests/helpers/interval/test_interval.py
index 1a934b81c..352965ce0 100644
--- a/tests/helpers/interval/test_interval.py
+++ b/tests/helpers/interval/test_interval.py
@@ -35,7 +35,7 @@ def test_contained(one, other):
 ])
 def test_not_contained(one, other):
     assert other not in one
-    assert not (other in one)
+    assert not (other in one)  # noqa
 
 
 def test_begin_greater_than_end():
diff --git a/tests/helpers/test_host.py b/tests/helpers/test_host.py
index 2cfb0e1d9..b87da1b0e 100644
--- a/tests/helpers/test_host.py
+++ b/tests/helpers/test_host.py
@@ -1,7 +1,6 @@
 # Copyright (c) 2015 The Pycroft Authors. See the AUTHORS file.
 # This file is part of the Pycroft project and licensed under the terms of
 # the Apache License, Version 2.0. See the LICENSE file for details.
-from dataclasses import dataclass
 from random import shuffle
 
 import ipaddr
@@ -78,7 +77,7 @@ def build_full_subnet(interface):
     def _build():
         net = factories.SubnetFactory.build()
 
-        for num in range(0, calculate_usable_ips(net)):
+        for _ in range(0, calculate_usable_ips(net)):
             ip, _ = get_free_ip((net,))
             net.ips.append(IP(address=ip, subnet=net, interface=interface))
         return net
diff --git a/tests/ldap_sync/conftest.py b/tests/ldap_sync/conftest.py
index 642bd5bdf..50a5c391b 100644
--- a/tests/ldap_sync/conftest.py
+++ b/tests/ldap_sync/conftest.py
@@ -112,7 +112,7 @@ def clean_ldap_base(get_connection, sync_config):
             },
         )
         if not result:  # pragma: no cover
-            raise RuntimeError(f"Could not create default password policy", result)
+            raise RuntimeError("Could not create default password policy", result)
     _cleanup_conn(conn)
 
 
diff --git a/tests/ldap_sync/test_ldap_sync.py b/tests/ldap_sync/test_ldap_sync.py
index 22ae975a3..3a27e8470 100644
--- a/tests/ldap_sync/test_ldap_sync.py
+++ b/tests/ldap_sync/test_ldap_sync.py
@@ -421,9 +421,8 @@ def test_mail_deletion(self, conn, session, sync_config, sync_all):
         modified_user.email = None
         session.add(modified_user)
         session.flush()
-        id = modified_user.id
 
-        user_records_to_sync = list(
+        user_records_to_sync = list(  # noqa
             fetch_db_users(
                 session,
                 sync_config.user_base_dn,
diff --git a/tests/lib/infrastructure/test_switch.py b/tests/lib/infrastructure/test_switch.py
index 49172cf1e..0eb1a8ba6 100644
--- a/tests/lib/infrastructure/test_switch.py
+++ b/tests/lib/infrastructure/test_switch.py
@@ -2,10 +2,8 @@
 #  This file is part of the Pycroft project and licensed under the terms of
 #  the Apache License, Version 2.0. See the LICENSE file for details
 import ipaddr
-import pytest
 
 from pycroft.lib import infrastructure as infra
-from pycroft.model.logging import RoomLogEntry
 from tests import factories
 
 
diff --git a/tests/lib/user/test_create_user.py b/tests/lib/user/test_create_user.py
index 7ef97c249..c3f52d4c5 100644
--- a/tests/lib/user/test_create_user.py
+++ b/tests/lib/user/test_create_user.py
@@ -1,5 +1,4 @@
 import dataclasses
-import operator
 from datetime import date
 
 import pytest
diff --git a/tests/model/test_finance.py b/tests/model/test_finance.py
index 3ebb52012..a4057ee66 100644
--- a/tests/model/test_finance.py
+++ b/tests/model/test_finance.py
@@ -4,7 +4,6 @@
 from functools import partial
 
 import pytest
-from psycopg2.errorcodes import INVALID_TEXT_REPRESENTATION
 from sqlalchemy import select, func, text
 from sqlalchemy.exc import IntegrityError, DataError
 
diff --git a/tests/model/test_hades.py b/tests/model/test_hades.py
index c5c359eb0..fd2aa3dc9 100644
--- a/tests/model/test_hades.py
+++ b/tests/model/test_hades.py
@@ -85,7 +85,7 @@ def test_radcheck(self, session, user, switch):
             assert row.NASIPAddress == switch.management_ip
             assert row.Attribute == "User-Name"
             assert row.Op == "=*"
-            assert row.Value == None
+            assert row.Value is None
             assert row.Priority == 10
 
         assert {row.NASPortId for row in rows} \
diff --git a/tests/model/test_host.py b/tests/model/test_host.py
index 6d575e971..80ec2b1e9 100644
--- a/tests/model/test_host.py
+++ b/tests/model/test_host.py
@@ -1,7 +1,6 @@
 # Copyright (c) 2015 The Pycroft Authors. See the AUTHORS file.
 # This file is part of the Pycroft project and licensed under the terms of
 # the Apache License, Version 2.0. See the LICENSE file for details.
-import re
 from itertools import chain
 
 import pytest
diff --git a/tests/model/test_property.py b/tests/model/test_property.py
index 6d9906efb..e0fd26330 100644
--- a/tests/model/test_property.py
+++ b/tests/model/test_property.py
@@ -233,8 +233,12 @@ def test_user_property_groups(self, session, utcnow, user, property_group1, prop
         assert res == 2
 
 
-h = lambda x: timedelta(hours=x)
-d = lambda x: timedelta(days=x)
+def h(x):
+    return timedelta(hours=x)
+
+
+def d(x):
+    return timedelta(days=x)
 
 
 class Test_Membership:
diff --git a/tests/model/test_user.py b/tests/model/test_user.py
index ce1b855db..ba2b234f6 100644
--- a/tests/model/test_user.py
+++ b/tests/model/test_user.py
@@ -49,7 +49,7 @@ def test_set_and_verify_password(self, user, session):
         # Also, why do we depend on `generate_password` instead of testing it separately?
         # All of this is very unperformant with little benefit.
         for length in range(4, 10):
-            for cnt in range(1, 3):
+            for _ in range(1, 3):
                 pw = generate_password(length)
                 if pw == password:
                     continue
diff --git a/tests/table/test_bootstrap_table.py b/tests/table/test_bootstrap_table.py
index 0689b8aac..9e36e5349 100644
--- a/tests/table/test_bootstrap_table.py
+++ b/tests/table/test_bootstrap_table.py
@@ -16,7 +16,7 @@ def test_instatiation_with_name_and_title_works(self):
         assert c.name == "test_col"
         assert c.title == "Test Column"
         assert c.width == 0
-        assert c.cell_style == False
+        assert c.cell_style is False
         assert repr(c) == "<Column 'test_col' title='Test Column'>"
 
     def test_instantiation_without_name(self):
@@ -295,7 +295,9 @@ def test_table_header_generation(self, header):
         expected_field_names = ["split1_foo", "split1_bar", "split2_foo", "split2_bar"]
         observed_attr_strings = (m[0] for m in small_col_matches)
 
-        for expected_field_name, attr_string in zip(expected_field_names, observed_attr_strings):
+        for expected_field_name, attr_string in zip(
+            expected_field_names, observed_attr_strings, strict=True
+        ):
             DATA_FIELD_RE = r'data-field="(\w+)"'
             observed_field_name = re.search(DATA_FIELD_RE, attr_string).group(1)
             assert observed_field_name == expected_field_name
diff --git a/web/api/v0/__init__.py b/web/api/v0/__init__.py
index 31c91fd36..209aa4174 100644
--- a/web/api/v0/__init__.py
+++ b/web/api/v0/__init__.py
@@ -4,17 +4,14 @@
 from flask import jsonify, request, current_app
 from flask_restful import Api, Resource as FlaskRestfulResource, abort, \
     reqparse, inputs
-from ipaddr import IPAddress
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy import select, func
 from sqlalchemy.orm import joinedload, selectinload
 
 from pycroft.helpers import utc
 from pycroft.helpers.i18n import Message
-from pycroft.lib.finance import build_transactions_query, estimate_balance, \
-    get_last_import_date
-from pycroft.lib.host import change_mac, host_create, interface_create, \
-    host_edit
+from pycroft.lib.finance import estimate_balance, get_last_import_date
+from pycroft.lib.host import change_mac, host_create, interface_create, host_edit
 from pycroft.lib.net import SubnetFullException
 from pycroft.lib.swdd import get_swdd_person_id, get_relevant_tenancies, \
     get_first_tenancy_with_room
@@ -183,7 +180,7 @@ def post(self, user_id):
         try:
             edit_email(user, args.new_email, args.forwarded, processor=user)
             session.session.commit()
-        except IllegalEmailError as e:
+        except IllegalEmailError:
             abort(400, message='Invalid email address.')
         return "Email has been changed."
 
diff --git a/web/app.py b/web/app.py
index 8217d7d9b..fa0251ad9 100644
--- a/web/app.py
+++ b/web/app.py
@@ -96,7 +96,7 @@ def make_app(debug=False, hades_logs=True):
     template_filters.register_filters(app)
     template_tests.register_checks(app)
 
-    babel = Babel(app)
+    Babel(app)
     if hades_logs:
         try:
             HadesLogs(app)
@@ -153,7 +153,7 @@ def debug_sentry():
         app.logger.info("An info log for inbetween")
         app.logger.error("Someone used the debug-sentry endpoint! Also, this is a test error.",
                          extra={'pi': 3.141})
-        div_by_zero = 1 / 0
+        div_by_zero = 1 / 0  # noqa
 
     @app.teardown_request
     def shutdown_session(exception=None):
diff --git a/web/blueprints/access.py b/web/blueprints/access.py
index 2a7e41309..6318ec741 100644
--- a/web/blueprints/access.py
+++ b/web/blueprints/access.py
@@ -67,7 +67,6 @@ def require(self, *required_properties):
         :param str required_properties: Names of the properties that are
         required.
         """
-        global_properties = self.required_properties
         view_properties = required_properties
 
         def decorator(f):
diff --git a/web/blueprints/facilities/__init__.py b/web/blueprints/facilities/__init__.py
index 5dc60cb33..e255a0ef1 100644
--- a/web/blueprints/facilities/__init__.py
+++ b/web/blueprints/facilities/__init__.py
@@ -9,7 +9,6 @@
     :copyright: (c) 2012 by AG DSN.
 """
 from collections import defaultdict
-from operator import and_
 
 from flask import (Blueprint, flash, jsonify, render_template, url_for,
                    redirect, request, abort)
@@ -365,7 +364,7 @@ def patch_port_edit(switch_room_id, patch_port_id):
         return redirect(url_for('.room_show', room_id=switch_room_id))
 
     if not patch_port.switch_room == switch_room:
-        flash(f"Patch-Port ist nicht im Switchraum!", "error")
+        flash("Patch-Port ist nicht im Switchraum!", "error")
         return redirect(url_for('.room_show', room_id=switch_room_id))
 
     form = PatchPortForm(switch_room=switch_room.short_name,
@@ -421,7 +420,7 @@ def patch_port_delete(switch_room_id, patch_port_id):
         return redirect(url_for('.room_show', room_id=switch_room_id))
 
     if not patch_port.switch_room == switch_room:
-        flash(f"Patch-Port ist nicht im Switchraum!", "error")
+        flash("Patch-Port ist nicht im Switchraum!", "error")
         return redirect(url_for('.room_show', room_id=switch_room_id))
 
     form = Form()
diff --git a/web/blueprints/facilities/address.py b/web/blueprints/facilities/address.py
index 8507f0425..56924189b 100644
--- a/web/blueprints/facilities/address.py
+++ b/web/blueprints/facilities/address.py
@@ -18,8 +18,10 @@ def get_address_entity(type: str) -> InstrumentedAttribute:
     try:
         return ADDRESS_ENTITIES[type]
     except KeyError:
-        raise ValueError(f"Unknown Address type '{type!r}'."
-                         f" Accepted: {' '.join(ADDRESS_ENTITIES)}")
+        raise ValueError(
+            f"Unknown Address type '{type!r}'."
+            f" Accepted: {' '.join(ADDRESS_ENTITIES)}"
+        ) from None
 
 
 def address_entity_search_query(query: str, entity: InstrumentedAttribute, session: Session, limit: int):
diff --git a/web/blueprints/finance/__init__.py b/web/blueprints/finance/__init__.py
index dd6ebfb5d..950970b9b 100644
--- a/web/blueprints/finance/__init__.py
+++ b/web/blueprints/finance/__init__.py
@@ -62,6 +62,8 @@
 from web.template_filters import date_filter, money_filter, datetime_filter
 from web.template_tests import privilege_check
 
+from . import forms
+
 bp = Blueprint('finance', __name__)
 access = BlueprintAccess(bp, required_properties=['finance_show'])
 nav = BlueprintNavigation(bp, "Finanzen", icon='fa-euro-sign', blueprint_access=access)
@@ -122,7 +124,7 @@ def actions(activity_id):
 
     activity_q = (BankAccountActivity.q
                   .options(joinedload(BankAccountActivity.bank_account))
-                  .filter(BankAccountActivity.transaction_id == None))
+                  .filter(BankAccountActivity.transaction_id is None))
 
     return jsonify(items=[{
         'bank_account': activity.bank_account.name,
@@ -356,8 +358,7 @@ def bank_account_activities_edit(activity_id):
             obj=activity, bank_account_name=activity.bank_account.name)
 
         if activity.transaction_id:
-            flash(f"Bankbewegung ist bereits zugewiesen!",
-                  'warning')
+            flash("Bankbewegung ist bereits zugewiesen!", "warning")
 
         form_args = {
             'form': form,
@@ -527,7 +528,7 @@ def accounts_list():
     accounts_by_type = {
         t[0]: list(t[1])
         for t in groupby(
-            Account.q.filter_by(legacy=False).outerjoin(User).filter(User.id == None)
+            Account.q.filter_by(legacy=False).outerjoin(User).filter(User.id.is_(None))
                 .order_by(Account.type).all(),
             lambda a: a.type.value
         )
@@ -913,7 +914,7 @@ def transactions_all_json():
                  (User.account_id == Split.account_id),
                  isouter=True))
                                  .group_by(Split.transaction_id)
-                                 .having(func.bool_and(User.id == None))
+                                 .having(func.bool_and(User.id.is_(None)))
                                  .alias("nut"))
 
         tid = literal_column("nut.transaction_id")
@@ -1227,7 +1228,7 @@ def json_accounts_system():
             "account_name": localized(account.name),
             "account_type": account.type.value
         } for account in Account.q.outerjoin(User).filter(
-            and_(User.account == None,
+            and_(User.account.is_(None),
                  Account.type != AccountType.USER_ASSET)
         ).all()])
 
diff --git a/web/blueprints/helpers/fints.py b/web/blueprints/helpers/fints.py
index 1d337ee77..2ec9e016c 100644
--- a/web/blueprints/helpers/fints.py
+++ b/web/blueprints/helpers/fints.py
@@ -24,7 +24,6 @@ def get_filtered_transactions(self, account: SEPAAccount,
         :return: A tuple with list of mt940.models.Transaction objects and another
         list with tuples of mt940-data and error messages.
         """
-        with_error = []
         with self._get_dialog() as dialog:
             hkkaz = self._find_highest_supported_command(HKKAZ5, HKKAZ6, HKKAZ7)
 
diff --git a/web/blueprints/task/tables.py b/web/blueprints/task/tables.py
index 3c396d49e..616e46265 100644
--- a/web/blueprints/task/tables.py
+++ b/web/blueprints/task/tables.py
@@ -18,16 +18,15 @@ class TaskTable(BootstrapTable):
     exception_message = Column(title=None, hide_if=lambda: True)
     type = Column("Typ", hide_if=lambda: True)
 
-    def __init__(self, hidden_columns=[], sort_order='asc', *a, **kw):
-        table_args = kw.pop('table_args', {})
-        table_args.setdefault('data-detail-view', "true")
-        table_args.setdefault('data-sort-name', "due")
-        table_args.setdefault('data-sort-order', sort_order)
-        table_args.setdefault('data-row-style', "table.taskRowFormatter")
-        table_args.setdefault('data-detail-formatter',
-                              "table.taskDetailFormatter")
+    def __init__(self, hidden_columns: set[str] = None, sort_order="asc", *a, **kw):
+        table_args = kw.pop("table_args", {})
+        table_args.setdefault("data-detail-view", "true")
+        table_args.setdefault("data-sort-name", "due")
+        table_args.setdefault("data-sort-order", sort_order)
+        table_args.setdefault("data-row-style", "table.taskRowFormatter")
+        table_args.setdefault("data-detail-formatter", "table.taskDetailFormatter")
 
-        if 'user' in hidden_columns:
+        if hidden_columns and "user" in hidden_columns:
             self.user.hide_if = lambda: True
         else:
             self.user.hide_if = lambda: False
diff --git a/web/blueprints/user/__init__.py b/web/blueprints/user/__init__.py
index 00c59b2ca..20e15518a 100644
--- a/web/blueprints/user/__init__.py
+++ b/web/blueprints/user/__init__.py
@@ -899,7 +899,7 @@ def block(user_id):
 
         try:
             during = closedopen(session.utcnow(), ends_at)
-            blocked_user = lib.user.block(
+            lib.user.block(
                 user=myUser,
                 reason=form.reason.data,
                 processor=current_user,
diff --git a/web/blueprints/user/log.py b/web/blueprints/user/log.py
index a58f6de3a..618189f73 100644
--- a/web/blueprints/user/log.py
+++ b/web/blueprints/user/log.py
@@ -11,7 +11,6 @@
 from hades_logs import hades_logs
 from hades_logs.exc import HadesConfigError, HadesOperationalError, HadesTimeout
 from pycroft.model import session
-from pycroft.model.facilities import Room
 from pycroft.model.host import SwitchPort
 from pycroft.model.port import PatchPort
 from pycroft.model.user import User
diff --git a/web/template_filters.py b/web/template_filters.py
index 92485acda..6e2f4a171 100644
--- a/web/template_filters.py
+++ b/web/template_filters.py
@@ -11,7 +11,6 @@
 """
 import pathlib
 from cmath import log
-from datetime import datetime
 from itertools import chain
 from re import sub
 
diff --git a/web/templates/infrastructure/switch_show.html b/web/templates/infrastructure/switch_show.html
index 41f0d541e..aa581196f 100644
--- a/web/templates/infrastructure/switch_show.html
+++ b/web/templates/infrastructure/switch_show.html
@@ -32,7 +32,7 @@ <h2 class="page-header">Überblick</h2>
             <dt>Management IP</dt>
             <dd>{{ switch.management_ip }}</dd>
             <dt>Standort</dt>
-            <dd>{% if switch.host.room != None %}{{ misc.room_link(switch.host.room) }}{% else %}unbekannt{% endif %}</dd>
+            <dd>{% if switch.host.room is not None %}{{ misc.room_link(switch.host.room) }}{% else %}unbekannt{% endif %}</dd>
         </dl>
     </section>
     <section>