56 files changed, 305 insertions, 579 deletions

diff --git a/src/mailman/__init__.py b/src/mailman/__init__.py
index 15ce69608..445be2b0d 100644
--- a/src/mailman/__init__.py
+++ b/src/mailman/__init__.py
@@ -41,3 +41,16 @@ if 'build_sphinx' not in sys.argv:                  # pragma: no cover
     else:
         from mailman.core.i18n import initialize
     initialize()
+
+
+# I hate myself: http://bugs.python.org/issue26632
+def public(thing):
+    if isinstance(thing, str):
+        mdict = sys._getframe(1).f_globals
+        name = thing
+    else:
+        mdict = sys.modules[thing.__module__].__dict__
+        name = thing.__name__
+    dunder_all = mdict.setdefault('__all__', [])
+    dunder_all.append(name)
+    return thing
diff --git a/src/mailman/app/bounces.py b/src/mailman/app/bounces.py
index acd1a740b..977b21038 100644
--- a/src/mailman/app/bounces.py
+++ b/src/mailman/app/bounces.py
@@ -17,15 +17,6 @@
 
 """Application level bounce handling."""
 
-__all__ = [
-    'ProbeVERP',
-    'StandardVERP',
-    'bounce_message',
-    'maybe_forward',
-    'send_probe',
-    ]
-
-
 import re
 import uuid
 import logging
@@ -33,6 +24,7 @@ import logging
 from email.mime.message import MIMEMessage
 from email.mime.text import MIMEText
 from email.utils import parseaddr
+from mailman import public
 from mailman.config import config
 from mailman.core.i18n import _
 from mailman.email.message import OwnerNotification, UserNotification
@@ -55,7 +47,7 @@ blog = logging.getLogger('mailman.bounce')
 DOT = '.'
 
 
-
+@public
 def bounce_message(mlist, msg, error=None):
     """Bounce the message back to the original author.
 
@@ -91,7 +83,6 @@ def bounce_message(mlist, msg, error=None):
     bmsg.send(mlist)
 
 
-
 class _BaseVERPParser:
     """Base class for parsing VERP messages.
 
@@ -143,7 +134,7 @@ class _BaseVERPParser:
         return verp_matches
 
 
-
+@public
 class StandardVERP(_BaseVERPParser):
     def __init__(self):
         super().__init__(config.mta.verp_regexp)
@@ -152,6 +143,7 @@ class StandardVERP(_BaseVERPParser):
         return '{0}@{1}'.format(*match_object.group('local', 'domain'))
 
 
+@public
 class ProbeVERP(_BaseVERPParser):
     def __init__(self):
         super().__init__(config.mta.verp_probe_regexp)
@@ -172,13 +164,13 @@ class ProbeVERP(_BaseVERPParser):
         return member.address.email
 
 
-
 @implementer(IPendable)
 class _ProbePendable(dict):
     """The pendable dictionary for probe messages."""
     PEND_TYPE = 'probe'
 
 
+@public
 def send_probe(member, msg):
     """Send a VERP probe to the member.
 
@@ -231,7 +223,7 @@ def send_probe(member, msg):
     return token
 
 
-
+@public
 def maybe_forward(mlist, msg):
     """Possibly forward bounce messages with no recognizable addresses.
 
@@ -249,7 +241,7 @@ def maybe_forward(mlist, msg):
     # (owners and moderators), or to the site administrators.  Most of the
     # notification is exactly the same in either case.
     adminurl = mlist.script_url('admin') + '/bounce'
-    subject=_('Uncaught bounce notification')
+    subject = _('Uncaught bounce notification')
     text = MIMEText(
         make('unrecognized.txt', mlist, adminurl=adminurl),
         _charset=mlist.preferred_language.charset)
@@ -258,7 +250,7 @@ def maybe_forward(mlist, msg):
             is UnrecognizedBounceDisposition.administrators):
         keywords = dict(roster=mlist.administrators)
     elif (mlist.forward_unrecognized_bounces_to
-              is UnrecognizedBounceDisposition.site_owner):
+          is UnrecognizedBounceDisposition.site_owner):
         keywords = {}
     else:
         raise AssertionError('Invalid forwarding disposition: {0}'.format(
diff --git a/src/mailman/app/commands.py b/src/mailman/app/commands.py
index 35158da2a..4c484bc0b 100644
--- a/src/mailman/app/commands.py
+++ b/src/mailman/app/commands.py
@@ -17,18 +17,14 @@
 
 """Initialize the email commands."""
 
-__all__ = [
-    'initialize',
-    ]
-
-
+from mailman import public
 from mailman.config import config
 from mailman.interfaces.command import IEmailCommand
 from mailman.utilities.modules import find_components
 from zope.interface.verify import verifyObject
 
 
-
+@public
 def initialize():
     """Initialize the email commands."""
     for command_class in find_components('mailman.commands', IEmailCommand):
diff --git a/src/mailman/app/digests.py b/src/mailman/app/digests.py
index fd708cb04..f8b217142 100644
--- a/src/mailman/app/digests.py
+++ b/src/mailman/app/digests.py
@@ -17,21 +17,16 @@
 
 """Digest functions."""
 
-__all__ = [
-    'bump_digest_number_and_volume',
-    'maybe_send_digest_now',
-    ]
-
-
 import os
 
+from mailman import public
 from mailman.config import config
 from mailman.email.message import Message
 from mailman.interfaces.digests import DigestFrequency
 from mailman.utilities.datetime import now as right_now
 
 
-
+@public
 def bump_digest_number_and_volume(mlist):
     """Bump the digest number and volume."""
     now = right_now()
@@ -72,7 +67,7 @@ def bump_digest_number_and_volume(mlist):
     mlist.digest_last_sent_at = now
 
 
-
+@public
 def maybe_send_digest_now(mlist, *, force=False):
     """Send this mailing list's digest now.
 
@@ -97,8 +92,7 @@ def maybe_send_digest_now(mlist, *, force=False):
         size = os.path.getsize(mailbox_path)
     except FileNotFoundError:
         size = 0
-    if (size >= mlist.digest_size_threshold * 1024.0 or
-        (force and size > 0)):
+    if (size >= mlist.digest_size_threshold * 1024.0 or (force and size > 0)):
         # Send the digest.  Because we don't want to hold up this process
         # with crafting the digest, we're going to move the digest file to
         # a safe place, then craft a fake message for the DigestRunner as
diff --git a/src/mailman/app/domain.py b/src/mailman/app/domain.py
index 72c4e69ff..66abf9c3e 100644
--- a/src/mailman/app/domain.py
+++ b/src/mailman/app/domain.py
@@ -17,17 +17,13 @@
 
 """Application level domain support."""
 
-__all__ = [
-    'handle_DomainDeletingEvent',
-    ]
-
-
+from mailman import public
 from mailman.interfaces.domain import DomainDeletingEvent
 from mailman.interfaces.listmanager import IListManager
 from zope.component import getUtility
 
 
-
+@public
 def handle_DomainDeletingEvent(event):
     """Delete all mailing lists in a domain when the domain is deleted."""
 
diff --git a/src/mailman/app/events.py b/src/mailman/app/events.py
index 6a170ad04..8b95bd4be 100644
--- a/src/mailman/app/events.py
+++ b/src/mailman/app/events.py
@@ -17,11 +17,7 @@
 
 """Global events."""
 
-__all__ = [
-    'initialize',
-    ]
-
-
+from mailman import public
 from mailman.app import (
     domain, membership, moderator, registrar, subscriptions)
 from mailman.core import i18n, switchboard
@@ -31,7 +27,7 @@ from mailman.utilities import passwords
 from zope import event
 
 
-
+@public
 def initialize():
     """Initialize global event subscribers."""
     event.subscribers.extend([
diff --git a/src/mailman/app/inject.py b/src/mailman/app/inject.py
index 528aa99c2..decc0fd0e 100644
--- a/src/mailman/app/inject.py
+++ b/src/mailman/app/inject.py
@@ -17,20 +17,15 @@
 
 """Inject a message into a queue."""
 
-__all__ = [
-    'inject_message',
-    'inject_text',
-    ]
-
-
 from email import message_from_string
 from email.utils import formatdate, make_msgid
+from mailman import public
 from mailman.config import config
 from mailman.email.message import Message
 from mailman.utilities.email import add_message_hash
 
 
-
+@public
 def inject_message(mlist, msg, recipients=None, switchboard=None, **kws):
     """Inject a message into a queue.
 
@@ -73,7 +68,7 @@ def inject_message(mlist, msg, recipients=None, switchboard=None, **kws):
     return config.switchboards[switchboard].enqueue(msg, **msgdata)
 
 
-
+@public
 def inject_text(mlist, text, recipients=None, switchboard=None, **kws):
     """Turn text into a message and inject that into a queue.
 
diff --git a/src/mailman/app/lifecycle.py b/src/mailman/app/lifecycle.py
index 94ccbcc50..50145ce8f 100644
--- a/src/mailman/app/lifecycle.py
+++ b/src/mailman/app/lifecycle.py
@@ -17,15 +17,11 @@
 
 """Application level list creation."""
 
-__all__ = [
-    'create_list',
-    'remove_list',
-    ]
-
-
 import shutil
 import logging
 
+from contextlib import suppress
+from mailman import public
 from mailman.config import config
 from mailman.interfaces.address import IEmailValidator
 from mailman.interfaces.domain import (
@@ -41,7 +37,7 @@ from zope.component import getUtility
 log = logging.getLogger('mailman.error')
 
 
-
+@public
 def create_list(fqdn_listname, owners=None, style_name=None):
     """Create the named list and apply styles.
 
@@ -89,14 +85,12 @@ def create_list(fqdn_listname, owners=None, style_name=None):
     return mlist
 
 
-
+@public
 def remove_list(mlist):
     """Remove the list and all associated artifacts and subscriptions."""
     # Remove the list's data directory, if it exists.
-    try:
+    with suppress(FileNotFoundError):
         shutil.rmtree(mlist.data_path)
-    except FileNotFoundError:
-        pass
     # Delete the mailing list from the database.
     getUtility(IListManager).delete(mlist)
     # Do the MTA-specific list deletion tasks
diff --git a/src/mailman/app/membership.py b/src/mailman/app/membership.py
index 81f221edc..8ded39388 100644
--- a/src/mailman/app/membership.py
+++ b/src/mailman/app/membership.py
@@ -17,14 +17,8 @@
 
 """Application support for membership management."""
 
-__all__ = [
-    'add_member',
-    'delete_member',
-    'handle_SubscriptionEvent',
-    ]
-
-
 from email.utils import formataddr
+from mailman import public
 from mailman.app.notifications import (
     send_admin_subscription_notice, send_goodbye_message,
     send_welcome_message)
@@ -41,7 +35,7 @@ from mailman.utilities.i18n import make
 from zope.component import getUtility
 
 
-
+@public
 def add_member(mlist, record, role=MemberRole.member):
     """Add a member right now.
 
@@ -99,7 +93,7 @@ def add_member(mlist, record, role=MemberRole.member):
     return member
 
 
-
+@public
 def delete_member(mlist, email, admin_notif=None, userack=None):
     """Delete a member right now.
 
@@ -142,7 +136,7 @@ def delete_member(mlist, email, admin_notif=None, userack=None):
         msg.send(mlist)
 
 
-
+@public
 def handle_SubscriptionEvent(event):
     if not isinstance(event, SubscriptionEvent):
         return
diff --git a/src/mailman/app/moderator.py b/src/mailman/app/moderator.py
index af2addea7..335c7a409 100644
--- a/src/mailman/app/moderator.py
+++ b/src/mailman/app/moderator.py
@@ -17,20 +17,11 @@
 
 """Application support for moderators."""
 
-__all__ = [
-    'handle_ListDeletingEvent',
-    'handle_message',
-    'handle_unsubscription',
-    'hold_message',
-    'hold_unsubscription',
-    'send_rejection',
-    ]
-
-
 import time
 import logging
 
 from email.utils import formatdate, getaddresses, make_msgid
+from mailman import public
 from mailman.app.membership import delete_member
 from mailman.config import config
 from mailman.core.i18n import _
@@ -51,7 +42,7 @@ vlog = logging.getLogger('mailman.vette')
 slog = logging.getLogger('mailman.subscribe')
 
 
-
+@public
 def hold_message(mlist, msg, msgdata=None, reason=None):
     """Hold a message for moderator approval.
 
@@ -97,7 +88,7 @@ def hold_message(mlist, msg, msgdata=None, reason=None):
     return request_id
 
 
-
+@public
 def handle_message(mlist, id, action, comment=None, forward=None):
     message_store = getUtility(IMessageStore)
     requestdb = IListRequests(mlist)
@@ -187,7 +178,7 @@ def handle_message(mlist, id, action, comment=None, forward=None):
         vlog.info(note, mlist.fqdn_listname, rejection, sender, subject)
 
 
-
+@public
 def hold_unsubscription(mlist, email):
     data = dict(email=email)
     requestsdb = IListRequests(mlist)
@@ -214,7 +205,7 @@ def hold_unsubscription(mlist, email):
     return request_id
 
 
-
+@public
 def handle_unsubscription(mlist, id, action, comment=None):
     requestdb = IListRequests(mlist)
     key, data = requestdb.get_request(id)
@@ -244,12 +235,12 @@ def handle_unsubscription(mlist, id, action, comment=None):
     requestdb.delete_request(id)
 
 
-
+@public
 def send_rejection(mlist, request, recip, comment, origmsg=None, lang=None):
     # As this message is going to the requester, try to set the language to
     # his/her language choice, if they are a member.  Otherwise use the list's
     # preferred language.
-    display_name = mlist.display_name
+    display_name = mlist.display_name               # flake8: noqa
     if lang is None:
         member = mlist.members.get_member(recip)
         lang = (mlist.preferred_language
@@ -276,7 +267,7 @@ def send_rejection(mlist, request, recip, comment, origmsg=None, lang=None):
     msg.send(mlist)
 
 
-
+@public
 def handle_ListDeletingEvent(event):
     if not isinstance(event, ListDeletingEvent):
         return
diff --git a/src/mailman/app/notifications.py b/src/mailman/app/notifications.py
index e28714eb5..09d5d2bc8 100644
--- a/src/mailman/app/notifications.py
+++ b/src/mailman/app/notifications.py
@@ -17,17 +17,11 @@
 
 """Sending notifications."""
 
-__all__ = [
-    'send_admin_subscription_notice',
-    'send_goodbye_message',
-    'send_welcome_message',
-    ]
-
-
 import logging
 
 from email.utils import formataddr
 from lazr.config import as_boolean
+from mailman import public
 from mailman.config import config
 from mailman.core.i18n import _
 from mailman.email.message import OwnerNotification, UserNotification
@@ -42,7 +36,6 @@ from zope.component import getUtility
 log = logging.getLogger('mailman.error')
 
 
-
 def _get_message(uri_template, mlist, language):
     if not uri_template:
         return ''
@@ -60,7 +53,7 @@ def _get_message(uri_template, mlist, language):
         return wrap(message)
 
 
-
+@public
 def send_welcome_message(mlist, member, language, text=''):
     """Send a welcome message to a subscriber.
 
@@ -98,7 +91,8 @@ def send_welcome_message(mlist, member, language, text=''):
         user_address=member.address.email,
         user_options_uri=options_url,
         ))
-    digmode = ('' if member.delivery_mode is DeliveryMode.regular
+    digmode = (''                                   # flake8: noqa
+               if member.delivery_mode is DeliveryMode.regular
                else _(' (Digest mode)'))
     msg = UserNotification(
         formataddr((display_name, member.address.email)),
@@ -109,7 +103,7 @@ def send_welcome_message(mlist, member, language, text=''):
     msg.send(mlist, verp=as_boolean(config.mta.verp_personalized_deliveries))
 
 
-
+@public
 def send_goodbye_message(mlist, address, language):
     """Send a goodbye message to a subscriber.
 
@@ -133,7 +127,7 @@ def send_goodbye_message(mlist, address, language):
     msg.send(mlist, verp=as_boolean(config.mta.verp_personalized_deliveries))
 
 
-
+@public
 def send_admin_subscription_notice(mlist, address, display_name):
     """Send the list administrators a subscription notice.
 
diff --git a/src/mailman/app/registrar.py b/src/mailman/app/registrar.py
index 7a6464a61..ca2804f5d 100644
--- a/src/mailman/app/registrar.py
+++ b/src/mailman/app/registrar.py
@@ -17,14 +17,9 @@
 
 """Implementation of the IRegistrar interface."""
 
-__all__ = [
-    'Registrar',
-    'handle_ConfirmationNeededEvent',
-    ]
-
-
 import logging
 
+from mailman import public
 from mailman.app.subscriptions import SubscriptionWorkflow
 from mailman.core.i18n import _
 from mailman.database.transaction import flush
@@ -40,13 +35,12 @@ from zope.interface import implementer
 log = logging.getLogger('mailman.error')
 
 
-
 @implementer(IPendable)
 class PendableRegistration(dict):
     PEND_TYPE = 'registration'
 
 
-
+@public
 @implementer(IRegistrar)
 class Registrar:
     """Handle registrations and confirmations for subscriptions."""
@@ -81,7 +75,7 @@ class Registrar:
                 SubscriptionWorkflow.__name__, token)
 
 
-
+@public
 def handle_ConfirmationNeededEvent(event):
     if not isinstance(event, ConfirmationNeededEvent):
         return
@@ -93,13 +87,13 @@ def handle_ConfirmationNeededEvent(event):
     subject = 'confirm ' + event.token
     confirm_address = event.mlist.confirm_address(event.token)
     # For i18n interpolation.
-    confirm_url = event.mlist.domain.confirm_url(event.token)
+    confirm_url = event.mlist.domain.confirm_url(event.token)   # flake8: noqa
     email_address = event.email
-    domain_name = event.mlist.domain.mail_host
-    contact_address = event.mlist.owner_address
+    domain_name = event.mlist.domain.mail_host      # flake8: noqa
+    contact_address = event.mlist.owner_address     # flake8: noqa
     # Send a verification email to the address.
     template = getUtility(ITemplateLoader).get(
-        'mailman:///{0}/{1}/confirm.txt'.format(
+        'mailman:///{}/{}/confirm.txt'.format(
             event.mlist.fqdn_listname,
             event.mlist.preferred_language.code))
     text = _(template)
diff --git a/src/mailman/app/replybot.py b/src/mailman/app/replybot.py
index f9e83dc9a..fc911c5a1 100644
--- a/src/mailman/app/replybot.py
+++ b/src/mailman/app/replybot.py
@@ -17,21 +17,10 @@
 
 """Application level auto-reply code."""
 
-# XXX This should undergo a rewrite to move this functionality off of the
-# mailing list.  The reply governor should really apply site-wide per
-# recipient (I think).
+from mailman import public
 
-__all__ = [
-    'can_acknowledge',
-    ]
 
-import logging
-
-
-log = logging.getLogger('mailman.vette')
-
-
-
+@public
 def can_acknowledge(msg):
     """A boolean specifying whether this message can be acknowledged.
 
diff --git a/src/mailman/app/subscriptions.py b/src/mailman/app/subscriptions.py
index a75d4361d..ca7ede14f 100644
--- a/src/mailman/app/subscriptions.py
+++ b/src/mailman/app/subscriptions.py
@@ -17,18 +17,13 @@
 
 """Handle subscriptions."""
 
-__all__ = [
-    'SubscriptionWorkflow',
-    'handle_ListDeletingEvent',
-    ]
-
-
 import uuid
 import logging
 
 from email.utils import formataddr
 from enum import Enum
 from datetime import timedelta
+from mailman import public
 from mailman.app.workflow import Workflow
 from mailman.core.i18n import _
 from mailman.email.message import UserNotification
@@ -64,7 +59,7 @@ class Pendable(dict):
     PEND_TYPE = 'subscription'
 
 
-
+@public
 class SubscriptionWorkflow(Workflow):
     """Workflow of a subscription request."""
 
@@ -225,10 +220,11 @@ class SubscriptionWorkflow(Workflow):
         # required we need to check that, otherwise we can go straight to
         # subscription.
         if self.pre_confirmed:
-            next_step = ('moderation_checks'
-                         if self.mlist.subscription_policy is
-                            SubscriptionPolicy.confirm_then_moderate
-                         else 'do_subscription')
+            next_step = (
+                'moderation_checks'
+                if self.mlist.subscription_policy is
+                    SubscriptionPolicy.confirm_then_moderate   # flake8: noqa
+                else 'do_subscription')
             self.push(next_step)
             return
         # The user must confirm their subscription.
@@ -327,11 +323,11 @@ class SubscriptionWorkflow(Workflow):
                          SubscriptionPolicy.moderate,
                          SubscriptionPolicy.confirm_then_moderate,
                          )
-                    else 'do_subscription')
+                     else 'do_subscription')
         self.push(next_step)
 
 
-
+@public
 def handle_ListDeletingEvent(event):
     """Delete a mailing list's members when the list is being deleted."""
 
diff --git a/src/mailman/app/templates.py b/src/mailman/app/templates.py
index 1d1203ad7..c01b9af47 100644
--- a/src/mailman/app/templates.py
+++ b/src/mailman/app/templates.py
@@ -17,12 +17,8 @@
 
 """Template loader."""
 
-__all__ = [
-    'TemplateLoader',
-    ]
-
-
 from contextlib import closing
+from mailman import public
 from mailman.interfaces.languages import ILanguageManager
 from mailman.interfaces.listmanager import IListManager
 from mailman.interfaces.templates import ITemplateLoader
@@ -35,7 +31,6 @@ from zope.component import getUtility
 from zope.interface import implementer
 
 
-
 class MailmanHandler(BaseHandler):
     # Handle internal mailman: URLs.
     def mailman_open(self, req):
@@ -94,7 +89,7 @@ class MailmanHandler(BaseHandler):
         return addinfourl(fp, {}, original_url)
 
 
-
+@public
 @implementer(ITemplateLoader)
 class TemplateLoader:
     """Loader of templates, with caching and support for mailman:// URIs."""
diff --git a/src/mailman/app/tests/test_bounces.py b/src/mailman/app/tests/test_bounces.py
index d53a74b6c..ffc1cf2b4 100644
--- a/src/mailman/app/tests/test_bounces.py
+++ b/src/mailman/app/tests/test_bounces.py
@@ -17,16 +17,6 @@
 
 """Testing app.bounces functions."""
 
-__all__ = [
-    'TestBounceMessage',
-    'TestMaybeForward',
-    'TestProbe',
-    'TestSendProbe',
-    'TestSendProbeNonEnglish',
-    'TestVERP',
-    ]
-
-
 import os
 import uuid
 import shutil
@@ -49,7 +39,6 @@ from mailman.testing.layers import ConfigLayer
 from zope.component import getUtility
 
 
-
 class TestVERP(unittest.TestCase):
     """Test header VERP detection."""
 
@@ -184,7 +173,6 @@ Apparently-To: test-bounces+bart=example.org@example.com
                          set(['anne@example.org', 'bart@example.org']))
 
 
-
 class TestSendProbe(unittest.TestCase):
     """Test sending of the probe message."""
 
@@ -218,25 +206,25 @@ Message-ID: <first>
     def test_probe_is_multipart(self):
         # The probe is a multipart/mixed with two subparts.
         send_probe(self._member, self._msg)
-        message = get_queue_messages('virgin')[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(message.get_content_type(), 'multipart/mixed')
         self.assertTrue(message.is_multipart())
         self.assertEqual(len(message.get_payload()), 2)
 
     def test_probe_sends_one_message(self):
-        # send_probe() places one message in the virgin queue.
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 0)
+        # send_probe() places one message in the virgin queue.  We start out
+        # with no messages in the queue.
+        get_queue_messages('virgin', expected_count=0)
         send_probe(self._member, self._msg)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        get_queue_messages('virgin', expected_count=1)
 
     def test_probe_contains_original(self):
         # Show that send_probe() places a properly formatted message in the
         # virgin queue.
         send_probe(self._member, self._msg)
-        message = get_queue_messages('virgin')[0].msg
-        rfc822 = message.get_payload(1)
+        items = get_queue_messages('virgin', expected_count=1)
+        rfc822 = items[0].msg.get_payload(1)
         self.assertEqual(rfc822.get_content_type(), 'message/rfc822')
         self.assertTrue(rfc822.is_multipart())
         self.assertEqual(len(rfc822.get_payload()), 1)
@@ -246,7 +234,8 @@ Message-ID: <first>
     def test_notice(self):
         # Test that the notice in the first subpart is correct.
         send_probe(self._member, self._msg)
-        message = get_queue_messages('virgin')[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         notice = message.get_payload(0)
         self.assertEqual(notice.get_content_type(), 'text/plain')
         # The interesting bits are the parts that have been interpolated into
@@ -254,15 +243,16 @@ Message-ID: <first>
         # interpolation values appear in the message.  When Python 2.7 is our
         # minimum requirement, we can use assertRegexpMatches().
         body = notice.get_payload()
-        self.assertTrue('test@example.com' in body)
-        self.assertTrue('anne@example.com' in body)
-        self.assertTrue('http://example.com/anne@example.com' in body)
-        self.assertTrue('test-owner@example.com' in body)
+        self.assertIn('test@example.com', body)
+        self.assertIn('anne@example.com', body)
+        self.assertIn('http://example.com/anne@example.com', body)
+        self.assertIn('test-owner@example.com', body)
 
     def test_headers(self):
         # Check the headers of the outer message.
         token = send_probe(self._member, self._msg)
-        message = get_queue_messages('virgin')[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(message['from'],
                          'test-bounces+{0}@example.com'.format(token))
         self.assertEqual(message['to'], 'anne@example.com')
@@ -271,15 +261,15 @@ Message-ID: <first>
     def test_no_precedence_header(self):
         # Probe messages should not have a Precedence header (LP: #808821).
         send_probe(self._member, self._msg)
-        message = get_queue_messages('virgin')[0].msg
-        self.assertEqual(message['precedence'], None)
+        items = get_queue_messages('virgin', expected_count=1)
+        self.assertIsNone(items[0].msg['precedence'])
 
 
-
 class TestSendProbeNonEnglish(unittest.TestCase):
     """Test sending of the probe message to a non-English speaker."""
 
     layer = ConfigLayer
+    maxDiff = None
 
     def setUp(self):
         self._mlist = create_list('test@example.com')
@@ -293,13 +283,15 @@ Message-ID: <first>
 """)
         # Set up the translation context.
         self._var_dir = tempfile.mkdtemp()
+        self.addCleanup(shutil.rmtree, self._var_dir)
         xx_template_path = os.path.join(
             self._var_dir, 'templates', 'site', 'xx', 'probe.txt')
         os.makedirs(os.path.dirname(xx_template_path))
         config.push('xx template dir', """\
         [paths.testing]
-        var_dir: {0}
+        var_dir: {}
         """.format(self._var_dir))
+        self.addCleanup(config.pop, 'xx template dir')
         language_manager = getUtility(ILanguageManager)
         language_manager.add('xx', 'utf-8', 'Freedonia')
         self._member.preferences.preferred_language = 'xx'
@@ -311,34 +303,28 @@ $address
 $optionsurl
 $owneraddr
 """, file=fp)
-        # Let assertMultiLineEqual work without bounds.
-        self.maxDiff = None
-
-    def tearDown(self):
-        config.pop('xx template dir')
-        shutil.rmtree(self._var_dir)
 
     def test_subject_with_member_nonenglish(self):
         # Test that members with non-English preferred language get a Subject
         # header in the expected language.
         send_probe(self._member, self._msg)
-        message = get_queue_messages('virgin')[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
         self.assertEqual(
-            message['subject'].encode(),
+            items[0].msg['subject'].encode(),
             '=?utf-8?q?ailing-may_ist-lay_Test_obe-pray_essage-may?=')
 
     def test_probe_notice_with_member_nonenglish(self):
         # Test that a member with non-English preferred language gets the
         # probe message in their language.
         send_probe(self._member, self._msg)
-        message = get_queue_messages('virgin')[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         notice = message.get_payload(0).get_payload()
         self.assertMultiLineEqual(notice, """\
 blah blah blah test@example.com anne@example.com
 http://example.com/anne@example.com test-owner@example.com""")
 
 
-
 class TestProbe(unittest.TestCase):
     """Test VERP probe parsing."""
 
@@ -361,7 +347,8 @@ Message-ID: <first>
         # based on the token in a probe bounce.
         token = send_probe(self._member, self._msg)
         # Simulate a bounce of the message in the virgin queue.
-        message = get_queue_messages('virgin')[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         bounce = mfs("""\
 To: {0}
 From: mail-daemon@example.com
@@ -370,10 +357,9 @@ From: mail-daemon@example.com
         addresses = ProbeVERP().get_verp(self._mlist, bounce)
         self.assertEqual(addresses, set(['anne@example.com']))
         # The pendable is no longer in the database.
-        self.assertEqual(getUtility(IPendings).confirm(token), None)
+        self.assertIsNone(getUtility(IPendings).confirm(token))
 
 
-
 class TestMaybeForward(unittest.TestCase):
     """Test forwarding of unrecognized bounces."""
 
@@ -384,6 +370,7 @@ class TestMaybeForward(unittest.TestCase):
         [mailman]
         site_owner: postmaster@example.com
         """)
+        self.addCleanup(config.pop, 'test config')
         self._mlist = create_list('test@example.com')
         self._mlist.send_welcome_message = False
         self._msg = mfs("""\
@@ -394,9 +381,6 @@ Message-ID: <first>
 
 """)
 
-    def tearDown(self):
-        config.pop('test config')
-
     def test_maybe_forward_discard(self):
         # When forward_unrecognized_bounces_to is set to discard, no bounce
         # messages are forwarded.
@@ -405,8 +389,7 @@ Message-ID: <first>
         # The only artifact of this call is a log file entry.
         mark = LogFileMark('mailman.bounce')
         maybe_forward(self._mlist, self._msg)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 0)
+        get_queue_messages('virgin', expected_count=0)
         line = mark.readline()
         self.assertEqual(
             line[-40:-1],
@@ -433,8 +416,7 @@ Message-ID: <first>
         self._mlist.forward_unrecognized_bounces_to = (
             UnrecognizedBounceDisposition.administrators)
         maybe_forward(self._mlist, self._msg)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('virgin', expected_count=1)
         msg = items[0].msg
         self.assertEqual(msg['subject'], 'Uncaught bounce notification')
         self.assertEqual(msg['from'], 'postmaster@example.com')
@@ -479,8 +461,7 @@ Message-ID: <first>
         self._mlist.forward_unrecognized_bounces_to = (
             UnrecognizedBounceDisposition.site_owner)
         maybe_forward(self._mlist, self._msg)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('virgin', expected_count=1)
         msg = items[0].msg
         self.assertEqual(msg['subject'], 'Uncaught bounce notification')
         self.assertEqual(msg['from'], 'postmaster@example.com')
@@ -501,10 +482,9 @@ Message-ID: <first>
         # All of the owners and moderators, but none of the members, should be
         # recipients of this message.
         self.assertEqual(items[0].msgdata['recipients'],
-                         set(['postmaster@example.com',]))
+                         set(['postmaster@example.com']))
 
 
-
 class TestBounceMessage(unittest.TestCase):
     """Test the `mailman.app.bounces.bounce_message()` function."""
 
@@ -523,6 +503,5 @@ Subject: Ignore
         # The message won't be bounced if it has no discernible sender.
         del self._msg['from']
         bounce_message(self._mlist, self._msg)
-        items = get_queue_messages('virgin')
         # Nothing in the virgin queue means nothing's been bounced.
-        self.assertEqual(items, [])
+        get_queue_messages('virgin', expected_count=0)
diff --git a/src/mailman/app/tests/test_digests.py b/src/mailman/app/tests/test_digests.py
index 80aee6439..c2919dcbb 100644
--- a/src/mailman/app/tests/test_digests.py
+++ b/src/mailman/app/tests/test_digests.py
@@ -17,12 +17,6 @@
 
 """Digest helper tests."""
 
-__all__ = [
-    'TestBumpDigest',
-    'TestMaybeSendDigest',
-    ]
-
-
 import os
 import unittest
 
@@ -41,7 +35,6 @@ from mailman.testing.layers import ConfigLayer
 from mailman.utilities.datetime import factory, now as right_now
 
 
-
 class TestBumpDigest(unittest.TestCase):
     layer = ConfigLayer
 
@@ -162,7 +155,6 @@ class TestBumpDigest(unittest.TestCase):
                           bump_digest_number_and_volume, self._mlist)
 
 
-
 class TestMaybeSendDigest(unittest.TestCase):
     layer = ConfigLayer
 
@@ -196,10 +188,9 @@ Subject: message {}
         self._runner.run()
         # There are no digests in flight now, and a single digest message has
         # been sent.
-        self.assertEqual(len(get_queue_messages('digest')), 0)
+        get_queue_messages('digest', expected_count=0)
         self.assertFalse(os.path.exists(self._mailbox_path))
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('virgin', expected_count=1)
         digest_contents = str(items[0].msg)
         self.assertIn('Subject: message 1', digest_contents)
         self.assertIn('Subject: message 2', digest_contents)
@@ -212,11 +203,10 @@ Subject: message {}
         maybe_send_digest_now(self._mlist)
         self._runner.run()
         # A digest is still being collected, but none have been sent.
-        self.assertEqual(len(get_queue_messages('digest')), 0)
+        get_queue_messages('digest', expected_count=0)
         self.assertGreater(os.path.getsize(self._mailbox_path), 0)
         self.assertLess(os.path.getsize(self._mailbox_path), 100 * 1024.0)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 0)
+        get_queue_messages('virgin', expected_count=0)
 
     def test_force_send_digest_under_threshold(self):
         # Put a few messages in the digest.
@@ -228,10 +218,9 @@ Subject: message {}
         self._runner.run()
         # There are no digests in flight now, and a single digest message has
         # been sent.
-        self.assertEqual(len(get_queue_messages('digest')), 0)
+        get_queue_messages('digest', expected_count=0)
         self.assertFalse(os.path.exists(self._mailbox_path))
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('virgin', expected_count=1)
         digest_contents = str(items[0].msg)
         self.assertIn('Subject: message 1', digest_contents)
         self.assertIn('Subject: message 2', digest_contents)
diff --git a/src/mailman/app/tests/test_inject.py b/src/mailman/app/tests/test_inject.py
index b8e311ed8..e71980163 100644
--- a/src/mailman/app/tests/test_inject.py
+++ b/src/mailman/app/tests/test_inject.py
@@ -17,12 +17,6 @@
 
 """Testing app.inject functions."""
 
-__all__ = [
-    'TestInjectMessage',
-    'TestInjectText',
-    ]
-
-
 import unittest
 
 from mailman.app.inject import inject_message, inject_text
@@ -37,7 +31,6 @@ from mailman.testing.layers import ConfigLayer
 NL = '\n'
 
 
-
 class TestInjectMessage(unittest.TestCase):
     """Test message injection."""
 
@@ -59,8 +52,7 @@ Nothing.
     def test_inject_message(self):
         # Test basic inject_message() call.
         inject_message(self.mlist, self.msg)
-        items = get_queue_messages('in')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('in', expected_count=1)
         self.assertMultiLineEqual(items[0].msg.as_string(),
                                   self.msg.as_string())
         self.assertEqual(items[0].msgdata['listid'], 'test.example.com')
@@ -71,16 +63,14 @@ Nothing.
         # Explicit recipients end up in the metadata.
         recipients = ['bart@example.com', 'cris@example.com']
         inject_message(self.mlist, self.msg, recipients)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertEqual(items[0].msgdata['recipients'], recipients)
 
     def test_inject_message_to_queue(self):
         # Explicitly use a different queue.
         inject_message(self.mlist, self.msg, switchboard='virgin')
-        items = get_queue_messages('in')
-        self.assertEqual(len(items), 0)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        get_queue_messages('in', expected_count=0)
+        items = get_queue_messages('virgin', expected_count=1)
         self.assertMultiLineEqual(items[0].msg.as_string(),
                                   self.msg.as_string())
         self.assertEqual(items[0].msgdata['listid'], 'test.example.com')
@@ -93,7 +83,7 @@ Nothing.
         self.assertNotIn('message-id', self.msg)
         inject_message(self.mlist, self.msg)
         self.assertIn('message-id', self.msg)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertIn('message-id', items[0].msg)
         self.assertEqual(items[0].msg['message-id'], self.msg['message-id'])
 
@@ -103,14 +93,14 @@ Nothing.
         self.assertNotIn('date', self.msg)
         inject_message(self.mlist, self.msg)
         self.assertIn('date', self.msg)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertIn('date', items[0].msg)
         self.assertEqual(items[0].msg['date'], self.msg['date'])
 
     def test_inject_message_with_keywords(self):
         # Keyword arguments are copied into the metadata.
         inject_message(self.mlist, self.msg, foo='yes', bar='no')
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertEqual(items[0].msgdata['foo'], 'yes')
         self.assertEqual(items[0].msgdata['bar'], 'no')
 
@@ -118,7 +108,7 @@ Nothing.
         # When the injected message has a Message-ID header, the injected
         # message will also get an Message-ID-Hash header.
         inject_message(self.mlist, self.msg)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertEqual(items[0].msg['message-id-hash'],
                          '4CMWUN6BHVCMHMDAOSJZ2Q72G5M32MWB')
 
@@ -130,12 +120,11 @@ Nothing.
         self.assertNotIn('message-id', self.msg)
         self.assertNotIn('message-id-hash', self.msg)
         inject_message(self.mlist, self.msg)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertIn('message-id', items[0].msg)
         self.assertIn('message-id-hash', items[0].msg)
 
 
-
 class TestInjectText(unittest.TestCase):
     """Test text injection."""
 
@@ -161,9 +150,8 @@ Nothing.
     def test_inject_text(self):
         # Test basic inject_text() call.
         inject_text(self.mlist, self.text)
-        items = get_queue_messages('in')
-        self.assertEqual(len(items), 1)
-        self.assertTrue(isinstance(items[0].msg, Message))
+        items = get_queue_messages('in', expected_count=1)
+        self.assertIsInstance(items[0].msg, Message)
         self.assertEqual(items[0].msg['message-id-hash'],
                          'GUXXQKNCHBFQAHGBFMGCME6HKZCUUH3K')
         # Delete these headers because they don't exist in the original text.
@@ -182,16 +170,14 @@ Nothing.
         # Explicit recipients end up in the metadata.
         recipients = ['bart@example.com', 'cris@example.com']
         inject_text(self.mlist, self.text, recipients)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertEqual(items[0].msgdata['recipients'], recipients)
 
     def test_inject_text_to_queue(self):
         # Explicitly use a different queue.
         inject_text(self.mlist, self.text, switchboard='virgin')
-        items = get_queue_messages('in')
-        self.assertEqual(len(items), 0)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        get_queue_messages('in', expected_count=0)
+        items = get_queue_messages('virgin', expected_count=1)
         # Remove the Message-ID-Hash header which isn't in the original text.
         del items[0].msg['message-id-hash']
         del items[0].msg['x-message-id-hash']
@@ -209,7 +195,7 @@ Nothing.
         filtered = self._remove_line('message-id')
         self.assertNotIn('Message-ID', filtered)
         inject_text(self.mlist, filtered)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertIn('message-id', items[0].msg)
 
     def test_inject_text_without_date(self):
@@ -217,14 +203,14 @@ Nothing.
         filtered = self._remove_line('date')
         self.assertNotIn('date', filtered)
         inject_text(self.mlist, self.text)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertIn('date', items[0].msg)
 
     def test_inject_text_adds_original_size(self):
         # The metadata gets an original_size attribute that is the length of
         # the injected text.
         inject_text(self.mlist, self.text)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertEqual(items[0].msgdata['original_size'],
                          # Add back the Message-ID-Hash and X-Message-ID-Hash
                          # headers which wer in the message contributing to the
@@ -235,7 +221,7 @@ Nothing.
     def test_inject_text_with_keywords(self):
         # Keyword arguments are copied into the metadata.
         inject_text(self.mlist, self.text, foo='yes', bar='no')
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertEqual(items[0].msgdata['foo'], 'yes')
         self.assertEqual(items[0].msgdata['bar'], 'no')
 
@@ -243,7 +229,7 @@ Nothing.
         # When the injected message has a Message-ID header, the injected
         # message will also get an Message-ID-Hash header.
         inject_text(self.mlist, self.text)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertEqual(items[0].msg['message-id-hash'],
                          'GUXXQKNCHBFQAHGBFMGCME6HKZCUUH3K')
 
@@ -255,6 +241,6 @@ Nothing.
         self.assertNotIn('Message-ID', filtered)
         self.assertNotIn('Message-ID-Hash', filtered)
         inject_text(self.mlist, filtered)
-        items = get_queue_messages('in')
+        items = get_queue_messages('in', expected_count=1)
         self.assertIn('message-id', items[0].msg)
         self.assertIn('message-id-hash', items[0].msg)
diff --git a/src/mailman/app/tests/test_lifecycle.py b/src/mailman/app/tests/test_lifecycle.py
index ad9e36e4f..d4ad067d2 100644
--- a/src/mailman/app/tests/test_lifecycle.py
+++ b/src/mailman/app/tests/test_lifecycle.py
@@ -17,11 +17,6 @@
 
 """Test the high level list lifecycle API."""
 
-__all__ = [
-    'TestLifecycle',
-    ]
-
-
 import os
 import shutil
 import unittest
@@ -34,7 +29,6 @@ from mailman.testing.layers import ConfigLayer
 from zope.component import getUtility
 
 
-
 class TestLifecycle(unittest.TestCase):
     """Test the high level list lifecycle API."""
 
diff --git a/src/mailman/app/tests/test_membership.py b/src/mailman/app/tests/test_membership.py
index ad61d875b..e17e5704b 100644
--- a/src/mailman/app/tests/test_membership.py
+++ b/src/mailman/app/tests/test_membership.py
@@ -17,12 +17,6 @@
 
 """Tests of application level membership functions."""
 
-__all__ = [
-    'TestAddMember',
-    'TestDeleteMember',
-    ]
-
-
 import unittest
 
 from mailman.app.lifecycle import create_list
@@ -38,7 +32,6 @@ from mailman.testing.layers import ConfigLayer
 from zope.component import getUtility
 
 
-
 class TestAddMember(unittest.TestCase):
     layer = ConfigLayer
 
@@ -229,7 +222,6 @@ class TestAddMember(unittest.TestCase):
         self.assertEqual(cm.exception.email, email.lower())
 
 
-
 class TestDeleteMember(unittest.TestCase):
     layer = ConfigLayer
 
diff --git a/src/mailman/app/tests/test_moderation.py b/src/mailman/app/tests/test_moderation.py
index e71b692c0..931b85fd0 100644
--- a/src/mailman/app/tests/test_moderation.py
+++ b/src/mailman/app/tests/test_moderation.py
@@ -17,12 +17,6 @@
 
 """Moderation tests."""
 
-__all__ = [
-    'TestModeration',
-    'TestUnsubscription',
-    ]
-
-
 import unittest
 
 from mailman.app.lifecycle import create_list
@@ -37,13 +31,13 @@ from mailman.runners.incoming import IncomingRunner
 from mailman.runners.outgoing import OutgoingRunner
 from mailman.runners.pipeline import PipelineRunner
 from mailman.testing.helpers import (
-    get_queue_messages, make_testable_runner, specialized_message_from_string)
+    get_queue_messages, make_testable_runner,
+    specialized_message_from_string as mfs)
 from mailman.testing.layers import SMTPLayer
 from mailman.utilities.datetime import now
 from zope.component import getUtility
 
 
-
 class TestModeration(unittest.TestCase):
     """Test moderation functionality."""
 
@@ -52,7 +46,7 @@ class TestModeration(unittest.TestCase):
     def setUp(self):
         self._mlist = create_list('test@example.com')
         self._request_db = IListRequests(self._mlist)
-        self._msg = specialized_message_from_string("""\
+        self._msg = mfs("""\
 From: anne@example.com
 To: test@example.com
 Subject: hold me
@@ -78,8 +72,8 @@ Message-ID: <alpha>
         message = messages[0]
         # We don't need to test the entire posted message, just the bits that
         # prove it got sent out.
-        self.assertTrue('x-mailman-version' in message)
-        self.assertTrue('x-peer' in message)
+        self.assertIn('x-mailman-version', message)
+        self.assertIn('x-peer', message)
         # The X-Mailman-Approved-At header has local timezone information in
         # it, so test that separately.
         self.assertEqual(message['x-mailman-approved-at'][:-5],
@@ -127,11 +121,10 @@ Message-ID: <alpha>
         handle_message(self._mlist, request_id, Action.discard,
                        forward=['zack@example.com'])
         # The forwarded message lives in the virgin queue.
-        messages = get_queue_messages('virgin')
-        self.assertEqual(len(messages), 1)
-        self.assertEqual(str(messages[0].msg['subject']),
+        items = get_queue_messages('virgin', expected_count=1)
+        self.assertEqual(str(items[0].msg['subject']),
                          'Forward of moderated message')
-        self.assertEqual(messages[0].msgdata['recipients'],
+        self.assertEqual(items[0].msgdata['recipients'],
                          ['zack@example.com'])
 
     def test_survive_a_deleted_message(self):
@@ -153,7 +146,6 @@ Message-ID: <alpha>
         self.assertEqual(message['subject'], 'hold me')
 
 
-
 class TestUnsubscription(unittest.TestCase):
     """Test unsubscription requests."""
 
diff --git a/src/mailman/app/tests/test_notifications.py b/src/mailman/app/tests/test_notifications.py
index 248ead6cc..09873f9bb 100644
--- a/src/mailman/app/tests/test_notifications.py
+++ b/src/mailman/app/tests/test_notifications.py
@@ -17,11 +17,6 @@
 
 """Test notifications."""
 
-__all__ = [
-    'TestNotifications',
-    ]
-
-
 import os
 import shutil
 import tempfile
@@ -39,7 +34,6 @@ from mailman.utilities.datetime import now
 from zope.component import getUtility
 
 
-
 class TestNotifications(unittest.TestCase):
     """Test notifications."""
 
@@ -51,10 +45,12 @@ class TestNotifications(unittest.TestCase):
         self._mlist.welcome_message_uri = 'mailman:///welcome.txt'
         self._mlist.display_name = 'Test List'
         self.var_dir = tempfile.mkdtemp()
+        self.addCleanup(shutil.rmtree, self.var_dir)
         config.push('template config', """\
         [paths.testing]
-        template_dir: {0}/templates
+        template_dir: {}/templates
         """.format(self.var_dir))
+        self.addCleanup(config.pop, 'template config')
         # Populate the template directories with a few fake templates.
         path = os.path.join(self.var_dir, 'templates', 'site', 'en')
         os.makedirs(path)
@@ -76,16 +72,11 @@ Welcome to the $list_name mailing list.
         # Let assertMultiLineEqual work without bounds.
         self.maxDiff = None
 
-    def tearDown(self):
-        config.pop('template config')
-        shutil.rmtree(self.var_dir)
-
     def test_welcome_message(self):
         subscribe(self._mlist, 'Anne', email='anne@example.com')
         # Now there's one message in the virgin queue.
-        messages = get_queue_messages('virgin')
-        self.assertEqual(len(messages), 1)
-        message = messages[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(str(message['subject']),
                          'Welcome to the "Test List" mailing list')
         self.assertMultiLineEqual(message.get_payload(), """\
@@ -113,9 +104,8 @@ Welcome to the Test List mailing list.
         address.preferences.preferred_language = 'xx'
         self._mlist.subscribe(address)
         # Now there's one message in the virgin queue.
-        messages = get_queue_messages('virgin')
-        self.assertEqual(len(messages), 1)
-        message = messages[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(str(message['subject']),
                          'Welcome to the "Test List" mailing list')
         self.assertMultiLineEqual(
@@ -126,40 +116,37 @@ Welcome to the Test List mailing list.
         # Welcome messages go only to mailing list members, not to owners.
         subscribe(self._mlist, 'Anne', MemberRole.owner, 'anne@example.com')
         # There is no welcome message in the virgin queue.
-        messages = get_queue_messages('virgin')
-        self.assertEqual(len(messages), 0)
+        get_queue_messages('virgin', expected_count=0)
 
     def test_no_welcome_message_to_nonmembers(self):
         # Welcome messages go only to mailing list members, not to nonmembers.
         subscribe(self._mlist, 'Anne', MemberRole.nonmember,
                   'anne@example.com')
         # There is no welcome message in the virgin queue.
-        messages = get_queue_messages('virgin')
-        self.assertEqual(len(messages), 0)
+        get_queue_messages('virgin', expected_count=0)
 
     def test_no_welcome_message_to_moderators(self):
         # Welcome messages go only to mailing list members, not to moderators.
         subscribe(self._mlist, 'Anne', MemberRole.moderator,
                   'anne@example.com')
         # There is no welcome message in the virgin queue.
-        messages = get_queue_messages('virgin')
-        self.assertEqual(len(messages), 0)
+        get_queue_messages('virgin', expected_count=0)
 
     def test_member_susbcribed_address_has_display_name(self):
         address = getUtility(IUserManager).create_address(
             'anne@example.com', 'Anne Person')
         address.verified_on = now()
         self._mlist.subscribe(address)
-        messages = get_queue_messages('virgin', expected_count=1)
-        message = messages[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(message['to'], 'Anne Person <anne@example.com>')
 
     def test_member_subscribed_address_has_no_display_name(self):
         address = getUtility(IUserManager).create_address('anne@example.com')
         address.verified_on = now()
         self._mlist.subscribe(address)
-        messages = get_queue_messages('virgin', expected_count=1)
-        message = messages[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(message['to'], 'anne@example.com')
 
     def test_member_is_user_and_has_display_name(self):
@@ -167,16 +154,16 @@ Welcome to the Test List mailing list.
             'anne@example.com', 'Anne Person')
         set_preferred(user)
         self._mlist.subscribe(user)
-        messages = get_queue_messages('virgin', expected_count=1)
-        message = messages[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(message['to'], 'Anne Person <anne@example.com>')
 
     def test_member_is_user_and_has_no_display_name(self):
         user = getUtility(IUserManager).create_user('anne@example.com')
         set_preferred(user)
         self._mlist.subscribe(user)
-        messages = get_queue_messages('virgin', expected_count=1)
-        message = messages[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(message['to'], 'anne@example.com')
 
     def test_member_has_linked_user_display_name(self):
@@ -187,8 +174,8 @@ Welcome to the Test List mailing list.
         address.verified_on = now()
         user.link(address)
         self._mlist.subscribe(address)
-        messages = get_queue_messages('virgin', expected_count=1)
-        message = messages[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(message['to'], 'Anne Person <anne2@example.com>')
 
     def test_member_has_no_linked_display_name(self):
@@ -198,8 +185,8 @@ Welcome to the Test List mailing list.
         address.verified_on = now()
         user.link(address)
         self._mlist.subscribe(address)
-        messages = get_queue_messages('virgin', expected_count=1)
-        message = messages[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(message['to'], 'anne2@example.com')
 
     def test_member_has_address_and_user_display_name(self):
@@ -211,6 +198,6 @@ Welcome to the Test List mailing list.
         address.verified_on = now()
         user.link(address)
         self._mlist.subscribe(address)
-        messages = get_queue_messages('virgin', expected_count=1)
-        message = messages[0].msg
+        items = get_queue_messages('virgin', expected_count=1)
+        message = items[0].msg
         self.assertEqual(message['to'], 'Anne X Person <anne2@example.com>')
diff --git a/src/mailman/app/tests/test_registrar.py b/src/mailman/app/tests/test_registrar.py
index 773b7b7aa..cec90c88b 100644
--- a/src/mailman/app/tests/test_registrar.py
+++ b/src/mailman/app/tests/test_registrar.py
@@ -17,11 +17,6 @@
 
 """Test email address registration."""
 
-__all__ = [
-    'TestRegistrar',
-    ]
-
-
 import unittest
 
 from mailman.app.lifecycle import create_list
@@ -37,7 +32,6 @@ from mailman.utilities.datetime import now
 from zope.component import getUtility
 
 
-
 class TestRegistrar(unittest.TestCase):
     """Test registration."""
 
@@ -151,8 +145,8 @@ class TestRegistrar(unittest.TestCase):
         # approve.  Running the workflow gives us a token.  Confirming the
         # token runs the workflow a little farther, but still gives us a
         # token.  Confirming again subscribes the user.
-        self._mlist.subscription_policy = \
-          SubscriptionPolicy.confirm_then_moderate
+        self._mlist.subscription_policy = (
+            SubscriptionPolicy.confirm_then_moderate)
         self._anne.verified_on = now()
         # Runs until subscription confirmation.
         token, token_owner, rmember = self._registrar.register(self._anne)
@@ -186,8 +180,8 @@ class TestRegistrar(unittest.TestCase):
         # confirm their subscription is different than the token the moderator
         # sees when they approve the subscription.  This prevents the user
         # from using a replay attack to subvert moderator approval.
-        self._mlist.subscription_policy = \
-          SubscriptionPolicy.confirm_then_moderate
+        self._mlist.subscription_policy = (
+            SubscriptionPolicy.confirm_then_moderate)
         self._anne.verified_on = now()
         # Runs until subscription confirmation.
         token, token_owner, rmember = self._registrar.register(self._anne)
@@ -248,8 +242,7 @@ class TestRegistrar(unittest.TestCase):
         # Anne is now a member.
         self.assertEqual(member.address.email, 'anne@example.com')
         # And there's a notification email waiting for Bart.
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('virgin', expected_count=1)
         message = items[0].msg
         self.assertEqual(message['To'], 'ant-owner@example.com')
         self.assertEqual(message['Subject'], 'Ant subscription notification')
@@ -272,5 +265,4 @@ anne@example.com has been successfully subscribed to Ant.""")
         # Anne is now a member.
         self.assertEqual(member.address.email, 'anne@example.com')
         # There's no notification email waiting for Bart.
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 0)
+        get_queue_messages('virgin', expected_count=0)
diff --git a/src/mailman/app/tests/test_subscriptions.py b/src/mailman/app/tests/test_subscriptions.py
index 3aaa5887a..02b5fe6da 100644
--- a/src/mailman/app/tests/test_subscriptions.py
+++ b/src/mailman/app/tests/test_subscriptions.py
@@ -17,11 +17,6 @@
 
 """Tests for the subscription service."""
 
-__all__ = [
-    'TestSubscriptionWorkflow',
-    ]
-
-
 import unittest
 
 from mailman.app.lifecycle import create_list
@@ -40,7 +35,6 @@ from unittest.mock import patch
 from zope.component import getUtility
 
 
-
 class TestSubscriptionWorkflow(unittest.TestCase):
     layer = ConfigLayer
     maxDiff = None
@@ -230,8 +224,8 @@ class TestSubscriptionWorkflow(unittest.TestCase):
         # The subscription policy requires user confirmation, but their
         # subscription is pre-confirmed.  Since moderation is required, that
         # check will be performed.
-        self._mlist.subscription_policy = \
-          SubscriptionPolicy.confirm_then_moderate
+        self._mlist.subscription_policy = (
+            SubscriptionPolicy.confirm_then_moderate)
         anne = self._user_manager.create_address(self._anne)
         workflow = SubscriptionWorkflow(self._mlist, anne,
                                         pre_verified=True,
@@ -244,8 +238,8 @@ class TestSubscriptionWorkflow(unittest.TestCase):
     def test_confirmation_checks_confirm_and_moderate_pre_confirmed(self):
         # The subscription policy requires user confirmation and moderation,
         # but their subscription is pre-confirmed.
-        self._mlist.subscription_policy = \
-          SubscriptionPolicy.confirm_then_moderate
+        self._mlist.subscription_policy = (
+            SubscriptionPolicy.confirm_then_moderate)
         anne = self._user_manager.create_address(self._anne)
         workflow = SubscriptionWorkflow(self._mlist, anne,
                                         pre_verified=True,
@@ -269,8 +263,8 @@ class TestSubscriptionWorkflow(unittest.TestCase):
     def test_confirmation_checks_moderate_confirmation_needed(self):
         # The subscription policy requires confirmation and moderation, and the
         # subscription is not pre-confirmed.
-        self._mlist.subscription_policy = \
-          SubscriptionPolicy.confirm_then_moderate
+        self._mlist.subscription_policy = (
+            SubscriptionPolicy.confirm_then_moderate)
         anne = self._user_manager.create_address(self._anne)
         workflow = SubscriptionWorkflow(self._mlist, anne, pre_verified=True)
         workflow.run_thru('confirmation_checks')
@@ -340,8 +334,8 @@ class TestSubscriptionWorkflow(unittest.TestCase):
         # An moderation-requiring subscription policy plus a pre-verified and
         # pre-approved address means the user gets subscribed to the mailing
         # list without any further confirmations or approvals.
-        self._mlist.subscription_policy = \
-          SubscriptionPolicy.confirm_then_moderate
+        self._mlist.subscription_policy = (
+            SubscriptionPolicy.confirm_then_moderate)
         anne = self._user_manager.create_address(self._anne)
         workflow = SubscriptionWorkflow(self._mlist, anne,
                                         pre_verified=True,
@@ -445,8 +439,7 @@ class TestSubscriptionWorkflow(unittest.TestCase):
                                         pre_confirmed=True)
         # Consume the entire state machine.
         list(workflow)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('virgin', expected_count=1)
         message = items[0].msg
         self.assertEqual(message['From'], 'test-owner@example.com')
         self.assertEqual(message['To'], 'test-owner@example.com')
@@ -471,8 +464,7 @@ approval:
                                         pre_confirmed=True)
         # Consume the entire state machine.
         list(workflow)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 0)
+        get_queue_messages('virgin', expected_count=0)
 
     def test_send_confirmation(self):
         # A confirmation message gets sent when the address is not verified.
@@ -481,8 +473,7 @@ approval:
         # Run the workflow to model the confirmation step.
         workflow = SubscriptionWorkflow(self._mlist, anne)
         list(workflow)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('virgin', expected_count=1)
         message = items[0].msg
         token = workflow.token
         self.assertEqual(message['Subject'], 'confirm {}'.format(token))
@@ -499,8 +490,7 @@ approval:
         # Run the workflow to model the confirmation step.
         workflow = SubscriptionWorkflow(self._mlist, anne, pre_confirmed=True)
         list(workflow)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('virgin', expected_count=1)
         message = items[0].msg
         token = workflow.token
         self.assertEqual(
@@ -517,8 +507,7 @@ approval:
         # Run the workflow to model the confirmation step.
         workflow = SubscriptionWorkflow(self._mlist, anne, pre_verified=True)
         list(workflow)
-        items = get_queue_messages('virgin')
-        self.assertEqual(len(items), 1)
+        items = get_queue_messages('virgin', expected_count=1)
         message = items[0].msg
         token = workflow.token
         self.assertEqual(
@@ -596,8 +585,8 @@ approval:
         # Ensure that if the workflow requires two confirmations, e.g. first
         # the user confirming their subscription, and then the moderator
         # approving it, that different tokens are used in these two cases.
-        self._mlist.subscription_policy = \
-          SubscriptionPolicy.confirm_then_moderate
+        self._mlist.subscription_policy = (
+            SubscriptionPolicy.confirm_then_moderate)
         anne = self._user_manager.create_address(self._anne)
         workflow = SubscriptionWorkflow(self._mlist, anne, pre_verified=True)
         # Run the state machine up to the first confirmation, and cache the
diff --git a/src/mailman/app/tests/test_templates.py b/src/mailman/app/tests/test_templates.py
index 9c8df4188..59bf74a0b 100644
--- a/src/mailman/app/tests/test_templates.py
+++ b/src/mailman/app/tests/test_templates.py
@@ -17,11 +17,6 @@
 
 """Test the template downloader API."""
 
-__all__ = [
-    'TestTemplateLoader',
-    ]
-
-
 import os
 import shutil
 import tempfile
@@ -35,7 +30,6 @@ from urllib.error import URLError
 from zope.component import getUtility
 
 
-
 class TestTemplateLoader(unittest.TestCase):
     """Test the template downloader API."""
 
@@ -43,10 +37,12 @@ class TestTemplateLoader(unittest.TestCase):
 
     def setUp(self):
         self.var_dir = tempfile.mkdtemp()
+        self.addCleanup(shutil.rmtree, self.var_dir)
         config.push('template config', """\
         [paths.testing]
         var_dir: {0}
         """.format(self.var_dir))
+        self.addCleanup(config.pop, 'template config')
         # Put a demo template in the site directory.
         path = os.path.join(self.var_dir, 'templates', 'site', 'en')
         os.makedirs(path)
@@ -55,10 +51,6 @@ class TestTemplateLoader(unittest.TestCase):
         self._loader = getUtility(ITemplateLoader)
         self._mlist = create_list('test@example.com')
 
-    def tearDown(self):
-        config.pop('template config')
-        shutil.rmtree(self.var_dir)
-
     def test_mailman_internal_uris(self):
         # mailman://demo.txt
         content = self._loader.get('mailman:///demo.txt')
diff --git a/src/mailman/app/tests/test_workflow.py b/src/mailman/app/tests/test_workflow.py
index 0d0ebc9fc..a5bbd0792 100644
--- a/src/mailman/app/tests/test_workflow.py
+++ b/src/mailman/app/tests/test_workflow.py
@@ -17,11 +17,6 @@
 
 """App-level workflow tests."""
 
-__all__ = [
-    'TestWorkflow',
-    ]
-
-
 import unittest
 
 from mailman.app.workflow import Workflow
@@ -52,7 +47,6 @@ class MyWorkflow(Workflow):
         return 'three'
 
 
-
 class TestWorkflow(unittest.TestCase):
     layer = ConfigLayer
 
diff --git a/src/mailman/app/workflow.py b/src/mailman/app/workflow.py
index 7508e9b37..eec8a14a8 100644
--- a/src/mailman/app/workflow.py
+++ b/src/mailman/app/workflow.py
@@ -17,16 +17,12 @@
 
 """Generic workflow."""
 
-__all__ = [
-    'Workflow',
-    ]
-
-
 import sys
 import json
 import logging
 
 from collections import deque
+from mailman import public
 from mailman.interfaces.workflow import IWorkflowStateManager
 from zope.component import getUtility
 
@@ -35,7 +31,7 @@ COMMASPACE = ', '
 log = logging.getLogger('mailman.error')
 
 
-
+@public
 class Workflow:
     """Generic workflow."""
 
diff --git a/src/mailman/archiving/mailarchive.py b/src/mailman/archiving/mailarchive.py
index 8a38abd67..782cec29a 100644
--- a/src/mailman/archiving/mailarchive.py
+++ b/src/mailman/archiving/mailarchive.py
@@ -17,11 +17,7 @@
 
 """The Mail-Archive.com archiver."""
 
-__all__ = [
-    'MailArchive',
-    ]
-
-
+from mailman import public
 from mailman.config import config
 from mailman.config.config import external_configuration
 from mailman.interfaces.archiver import ArchivePolicy, IArchiver
@@ -29,7 +25,7 @@ from urllib.parse import quote, urljoin
 from zope.interface import implementer
 
 
-
+@public
 @implementer(IArchiver)
 class MailArchive:
     """Public archiver at the Mail-Archive.com.
diff --git a/src/mailman/archiving/mhonarc.py b/src/mailman/archiving/mhonarc.py
index abe7f725a..3aa482bff 100644
--- a/src/mailman/archiving/mhonarc.py
+++ b/src/mailman/archiving/mhonarc.py
@@ -17,13 +17,9 @@
 
 """MHonArc archiver."""
 
-__all__ = [
-    'MHonArc',
-    ]
-
-
 import logging
 
+from mailman import public
 from mailman.config import config
 from mailman.config.config import external_configuration
 from mailman.interfaces.archiver import IArchiver
@@ -36,7 +32,7 @@ from zope.interface import implementer
 log = logging.getLogger('mailman.archiver')
 
 
-
+@public
 @implementer(IArchiver)
 class MHonArc:
     """Local MHonArc archiver."""
diff --git a/src/mailman/archiving/prototype.py b/src/mailman/archiving/prototype.py
index e8435370f..73983cf8d 100644
--- a/src/mailman/archiving/prototype.py
+++ b/src/mailman/archiving/prototype.py
@@ -26,9 +26,11 @@ import os
 import errno
 import logging
 
+from contextlib import suppress
 from datetime import timedelta
 from flufl.lock import Lock, TimeOutError
 from mailbox import Maildir
+from mailman import public
 from mailman.config import config
 from mailman.interfaces.archiver import IArchiver
 from zope.interface import implementer
@@ -37,7 +39,7 @@ from zope.interface import implementer
 log = logging.getLogger('mailman.error')
 
 
-
+@public
 @implementer(IArchiver)
 class Prototype:
     """A prototype of a third party archiver.
@@ -68,13 +70,8 @@ class Prototype:
         This archiver saves messages into a maildir.
         """
         archive_dir = os.path.join(config.ARCHIVE_DIR, 'prototype')
-        try:
+        with suppress(FileExistsError):
             os.makedirs(archive_dir, 0o775)
-        except OSError as error:
-            # If this already exists, then we're fine
-            if error.errno != errno.EEXIST:
-                raise
-
         # Maildir will throw an error if the directories are partially created
         # (for instance the toplevel exists but cur, new, or tmp do not)
         # therefore we don't create the toplevel as we did above.
diff --git a/src/mailman/model/address.py b/src/mailman/model/address.py
index b632f54e1..f33a7ef46 100644
--- a/src/mailman/model/address.py
+++ b/src/mailman/model/address.py
@@ -17,11 +17,6 @@
 
 """Model for addresses."""
 
-__all__ = [
-    'Address',
-    ]
-
-
 from email.utils import formataddr
 from mailman.database.model import Model
 from mailman.interfaces.address import (
@@ -34,7 +29,11 @@ from zope.event import notify
 from zope.interface import implementer
 
 
-
+__all__ = [
+    'Address',
+    ]
+
+
 @implementer(IAddress)
 class Address(Model):
     """See `IAddress`."""
diff --git a/src/mailman/model/autorespond.py b/src/mailman/model/autorespond.py
index 08a014fd2..00c329ff5 100644
--- a/src/mailman/model/autorespond.py
+++ b/src/mailman/model/autorespond.py
@@ -15,13 +15,7 @@
 # You should have received a copy of the GNU General Public License along with
 # GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
 
-"""Module stuff."""
-
-__all__ = [
-    'AutoResponseRecord',
-    'AutoResponseSet',
-    ]
-
+"""Autoresponder records."""
 
 from mailman.database.model import Model
 from mailman.database.transaction import dbconnection
@@ -33,8 +27,13 @@ from sqlalchemy import Column, Date, ForeignKey, Integer, desc
 from sqlalchemy.orm import relationship
 from zope.interface import implementer
 
+__all__ = [
+    'AutoResponseRecord',
+    'AutoResponseSet',
+    ]
+
+
 
-
 @implementer(IAutoResponseRecord)
 class AutoResponseRecord(Model):
     """See `IAutoResponseRecord`."""
@@ -59,7 +58,6 @@ class AutoResponseRecord(Model):
         self.date_sent = today()
 
 
-
 @implementer(IAutoResponseSet)
 class AutoResponseSet:
     """See `IAutoResponseSet`."""
diff --git a/src/mailman/model/bans.py b/src/mailman/model/bans.py
index a2a52a657..e81a7a01a 100644
--- a/src/mailman/model/bans.py
+++ b/src/mailman/model/bans.py
@@ -17,11 +17,6 @@
 
 """Ban manager."""
 
-__all__ = [
-    'BanManager',
-    ]
-
-
 import re
 
 from mailman.database.model import Model
@@ -30,8 +25,11 @@ from mailman.interfaces.bans import IBan, IBanManager
 from sqlalchemy import Column, Integer, Unicode
 from zope.interface import implementer
 
+__all__ = [
+    'BanManager',
+    ]
+
 
-
 @implementer(IBan)
 class Ban(Model):
     """See `IBan`."""
@@ -48,7 +46,6 @@ class Ban(Model):
         self.list_id = list_id
 
 
-
 @implementer(IBanManager)
 class BanManager:
     """See `IBanManager`."""
diff --git a/src/mailman/model/bounce.py b/src/mailman/model/bounce.py
index 3ccf58091..544907ad5 100644
--- a/src/mailman/model/bounce.py
+++ b/src/mailman/model/bounce.py
@@ -17,13 +17,6 @@
 
 """Bounce support."""
 
-__all__ = [
-    'BounceEvent',
-    'BounceProcessor',
-    ]
-
-
-
 from mailman.database.model import Model
 from mailman.database.transaction import dbconnection
 from mailman.database.types import Enum
@@ -34,7 +27,6 @@ from sqlalchemy import Boolean, Column, DateTime, Integer, Unicode
 from zope.interface import implementer
 
 
-
 @implementer(IBounceEvent)
 class BounceEvent(Model):
     """See `IBounceEvent`."""
@@ -59,7 +51,6 @@ class BounceEvent(Model):
         self.processed = False
 
 
-
 @implementer(IBounceProcessor)
 class BounceProcessor:
     """See `IBounceProcessor`."""
diff --git a/src/mailman/model/digests.py b/src/mailman/model/digests.py
index e5a49a8a7..39eef0c6f 100644
--- a/src/mailman/model/digests.py
+++ b/src/mailman/model/digests.py
@@ -17,11 +17,6 @@
 
 """One last digest."""
 
-__all__ = [
-    'OneLastDigest',
-    ]
-
-
 from mailman.database.model import Model
 from mailman.database.types import Enum
 from mailman.interfaces.digests import IOneLastDigest
@@ -30,8 +25,11 @@ from sqlalchemy import Column, Integer, ForeignKey
 from sqlalchemy.orm import relationship
 from zope.interface import implementer
 
+__all__ = [
+    'OneLastDigest',
+    ]
+
 
-
 @implementer(IOneLastDigest)
 class OneLastDigest(Model):
     """See `IOneLastDigest`."""
diff --git a/src/mailman/model/domain.py b/src/mailman/model/domain.py
index 7fb6d6821..fb73bf470 100644
--- a/src/mailman/model/domain.py
+++ b/src/mailman/model/domain.py
@@ -17,12 +17,6 @@
 
 """Domains."""
 
-__all__ = [
-    'Domain',
-    'DomainManager',
-    ]
-
-
 from mailman.database.model import Model
 from mailman.database.transaction import dbconnection
 from mailman.interfaces.domain import (
@@ -38,8 +32,12 @@ from zope.event import notify
 from zope.interface import implementer
 from zope.component import getUtility
 
+__all__ = [
+    'Domain',
+    'DomainManager',
+    ]
+
 
-
 @implementer(IDomain)
 class Domain(Model):
     """Domains."""
@@ -136,7 +134,6 @@ class Domain(Model):
         self.owners.remove(user_manager.get_user(owner))
 
 
-
 @implementer(IDomainManager)
 class DomainManager:
     """Domain manager."""
diff --git a/src/mailman/model/language.py b/src/mailman/model/language.py
index 33b0e2ef4..fd51f9522 100644
--- a/src/mailman/model/language.py
+++ b/src/mailman/model/language.py
@@ -17,18 +17,16 @@
 
 """Model for languages."""
 
-__all__ = [
-    'Language',
-    ]
-
-
 from mailman.database.model import Model
 from mailman.interfaces.languages import ILanguage
 from sqlalchemy import Column, Integer, Unicode
 from zope.interface import implementer
 
+__all__ = [
+    'Language',
+    ]
+
 
-
 @implementer(ILanguage)
 class Language(Model):
     """See `ILanguage`."""
diff --git a/src/mailman/model/listmanager.py b/src/mailman/model/listmanager.py
index 45f91bb6a..074b6b600 100644
--- a/src/mailman/model/listmanager.py
+++ b/src/mailman/model/listmanager.py
@@ -17,11 +17,6 @@
 
 """A mailing list manager."""
 
-__all__ = [
-    'ListManager',
-    ]
-
-
 from mailman.database.transaction import dbconnection
 from mailman.interfaces.address import InvalidEmailAddressError
 from mailman.interfaces.listmanager import (
@@ -36,8 +31,11 @@ from mailman.utilities.datetime import now
 from zope.event import notify
 from zope.interface import implementer
 
+__all__ = [
+    'ListManager',
+    ]
+
 
-
 @implementer(IListManager)
 class ListManager:
     """An implementation of the `IListManager` interface."""
diff --git a/src/mailman/model/mailinglist.py b/src/mailman/model/mailinglist.py
index 5b015e5b5..8e4df5f50 100644
--- a/src/mailman/model/mailinglist.py
+++ b/src/mailman/model/mailinglist.py
@@ -17,11 +17,6 @@
 
 """Model for mailing lists."""
 
-__all__ = [
-    'MailingList',
-    ]
-
-
 import os
 
 from mailman.config import config
@@ -65,6 +60,10 @@ from zope.component import getUtility
 from zope.event import notify
 from zope.interface import implementer
 
+__all__ = [
+    'MailingList',
+    ]
+
 
 SPACE = ' '
 UNDERSCORE = '_'
diff --git a/src/mailman/model/member.py b/src/mailman/model/member.py
index 1fb11218d..ecd1c3d9e 100644
--- a/src/mailman/model/member.py
+++ b/src/mailman/model/member.py
@@ -17,11 +17,6 @@
 
 """Model for members."""
 
-__all__ = [
-    'Member',
-    ]
-
-
 from mailman.core.constants import system_preferences
 from mailman.database.model import Model
 from mailman.database.transaction import dbconnection
@@ -40,11 +35,15 @@ from zope.component import getUtility
 from zope.event import notify
 from zope.interface import implementer
 
+__all__ = [
+    'Member',
+    ]
+
+
 
 uid_factory = UIDFactory(context='members')
 
 
-
 @implementer(IMember)
 class Member(Model):
     """See `IMember`."""
diff --git a/src/mailman/rules/administrivia.py b/src/mailman/rules/administrivia.py
index abb6527a2..b4656d33f 100644
--- a/src/mailman/rules/administrivia.py
+++ b/src/mailman/rules/administrivia.py
@@ -17,17 +17,16 @@
 
 """The administrivia rule."""
 
-__all__ = [
-    'Administrivia',
-    ]
-
-
 from email.iterators import typed_subpart_iterator
 from mailman.config import config
 from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'Administrivia',
+    ]
+
 
 # The list of email commands we search for in the Subject header and payload.
 # We probably should get this information from the actual implemented
@@ -48,7 +47,6 @@ EMAIL_COMMANDS = {
     }
 
 
-
 @implementer(IRule)
 class Administrivia:
     """The administrivia rule."""
diff --git a/src/mailman/rules/any.py b/src/mailman/rules/any.py
index e71b18639..67504875c 100644
--- a/src/mailman/rules/any.py
+++ b/src/mailman/rules/any.py
@@ -17,17 +17,15 @@
 
 """Check if any previous rules have matched."""
 
-__all__ = [
-    'Any',
-    ]
-
-
 from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'Any',
+    ]
+
 
-
 @implementer(IRule)
 class Any:
     """Look for any previous rule match."""
diff --git a/src/mailman/rules/approved.py b/src/mailman/rules/approved.py
index 3d16b44f9..cb3b98915 100644
--- a/src/mailman/rules/approved.py
+++ b/src/mailman/rules/approved.py
@@ -17,11 +17,6 @@
 
 """Look for moderator pre-approval."""
 
-__all__ = [
-    'Approved',
-    ]
-
-
 import re
 
 from email.iterators import typed_subpart_iterator
@@ -30,6 +25,10 @@ from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'Approved',
+    ]
+
 
 EMPTYSTRING = ''
 HEADERS = [
@@ -40,7 +39,6 @@ HEADERS = [
     ]
 
 
-
 @implementer(IRule)
 class Approved:
     """Look for moderator pre-approval."""
@@ -134,7 +132,6 @@ class Approved:
         return is_valid
 
 
-
 def reset_payload(part, payload):
     # Set decoded payload maintaining content-type, charset, format and delsp.
     charset = part.get_content_charset() or 'us-ascii'
diff --git a/src/mailman/rules/emergency.py b/src/mailman/rules/emergency.py
index 5f2208109..f6dacfe37 100644
--- a/src/mailman/rules/emergency.py
+++ b/src/mailman/rules/emergency.py
@@ -17,17 +17,15 @@
 
 """The emergency hold rule."""
 
-__all__ = [
-    'Emergency',
-    ]
-
-
 from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'Emergency',
+    ]
+
 
-
 @implementer(IRule)
 class Emergency:
     """The emergency hold rule."""
diff --git a/src/mailman/rules/implicit_dest.py b/src/mailman/rules/implicit_dest.py
index 484bd6a40..6d75ba637 100644
--- a/src/mailman/rules/implicit_dest.py
+++ b/src/mailman/rules/implicit_dest.py
@@ -17,11 +17,6 @@
 
 """The implicit destination rule."""
 
-__all__ = [
-    'ImplicitDestination',
-    ]
-
-
 import re
 
 from email.utils import getaddresses
@@ -30,8 +25,11 @@ from mailman.interfaces.mailinglist import IAcceptableAliasSet
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'ImplicitDestination',
+    ]
+
 
-
 @implementer(IRule)
 class ImplicitDestination:
     """The implicit destination rule."""
diff --git a/src/mailman/rules/loop.py b/src/mailman/rules/loop.py
index 4c5b00c0f..280939a74 100644
--- a/src/mailman/rules/loop.py
+++ b/src/mailman/rules/loop.py
@@ -17,17 +17,15 @@
 
 """Look for a posting loop."""
 
-__all__ = [
-    'Loop',
-    ]
-
-
 from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'Loop',
+    ]
+
 
-
 @implementer(IRule)
 class Loop:
     """Look for a posting loop."""
diff --git a/src/mailman/rules/max_recipients.py b/src/mailman/rules/max_recipients.py
index 8557aca44..3d4fa139f 100644
--- a/src/mailman/rules/max_recipients.py
+++ b/src/mailman/rules/max_recipients.py
@@ -17,18 +17,16 @@
 
 """The maximum number of recipients rule."""
 
-__all__ = [
-    'MaximumRecipients',
-    ]
-
-
 from email.utils import getaddresses
 from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'MaximumRecipients',
+    ]
+
 
-
 @implementer(IRule)
 class MaximumRecipients:
     """The maximum number of recipients rule."""
diff --git a/src/mailman/rules/max_size.py b/src/mailman/rules/max_size.py
index a4d5785d8..0ed781a38 100644
--- a/src/mailman/rules/max_size.py
+++ b/src/mailman/rules/max_size.py
@@ -17,17 +17,15 @@
 
 """The maximum message size rule."""
 
-__all__ = [
-    'MaximumSize',
-    ]
-
-
 from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'MaximumSize',
+    ]
+
 
-
 @implementer(IRule)
 class MaximumSize:
     """The implicit destination rule."""
diff --git a/src/mailman/rules/moderation.py b/src/mailman/rules/moderation.py
index ecf5cc8bf..b89e7c9c2 100644
--- a/src/mailman/rules/moderation.py
+++ b/src/mailman/rules/moderation.py
@@ -17,12 +17,6 @@
 
 """Membership related rules."""
 
-__all__ = [
-    'MemberModeration',
-    'NonmemberModeration',
-    ]
-
-
 import re
 
 from mailman.core.i18n import _
@@ -33,8 +27,12 @@ from mailman.interfaces.usermanager import IUserManager
 from zope.component import getUtility
 from zope.interface import implementer
 
+__all__ = [
+    'MemberModeration',
+    'NonmemberModeration',
+    ]
+
 
-
 @implementer(IRule)
 class MemberModeration:
     """The member moderation rule."""
@@ -65,7 +63,6 @@ class MemberModeration:
         return False
 
 
-
 def _record_action(msgdata, action, sender, reason):
     msgdata['moderation_action'] = action
     msgdata['moderation_sender'] = sender
@@ -88,13 +85,13 @@ class NonmemberModeration:
         # list, make them nonmembers.
         for sender in msg.senders:
             if (mlist.members.get_member(sender) is None and
-                mlist.nonmembers.get_member(sender) is None):
+                    mlist.nonmembers.get_member(sender) is None):
                 # The address is neither a member nor nonmember.
                 address = user_manager.get_address(sender)
                 assert address is not None, (
                     'Posting address is not registered: {0}'.format(sender))
                 mlist.subscribe(address, MemberRole.nonmember)
-        ## # If a member is found, the member-moderation rule takes precedence.
+        # If a member is found, the member-moderation rule takes precedence.
         for sender in msg.senders:
             if mlist.members.get_member(sender) is not None:
                 return False
diff --git a/src/mailman/rules/news_moderation.py b/src/mailman/rules/news_moderation.py
index e408043bb..2feeed4a1 100644
--- a/src/mailman/rules/news_moderation.py
+++ b/src/mailman/rules/news_moderation.py
@@ -17,18 +17,16 @@
 
 """The news moderation rule."""
 
-__all__ = [
-    'ModeratedNewsgroup',
-    ]
-
-
 from mailman.core.i18n import _
 from mailman.interfaces.nntp import NewsgroupModeration
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'ModeratedNewsgroup',
+    ]
+
 
-
 @implementer(IRule)
 class ModeratedNewsgroup:
     """The news moderation rule."""
diff --git a/src/mailman/rules/no_subject.py b/src/mailman/rules/no_subject.py
index 0348be5c5..ff63d8c37 100644
--- a/src/mailman/rules/no_subject.py
+++ b/src/mailman/rules/no_subject.py
@@ -17,17 +17,15 @@
 
 """The no-Subject header rule."""
 
-__all__ = [
-    'NoSubject',
-    ]
-
-
 from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'NoSubject',
+    ]
+
 
-
 @implementer(IRule)
 class NoSubject:
     """The no-Subject rule."""
diff --git a/src/mailman/rules/suspicious.py b/src/mailman/rules/suspicious.py
index f7dc50ab4..d385ea490 100644
--- a/src/mailman/rules/suspicious.py
+++ b/src/mailman/rules/suspicious.py
@@ -17,11 +17,6 @@
 
 """The historical 'suspicious header' rule."""
 
-__all__ = [
-    'SuspiciousHeader',
-    ]
-
-
 import re
 import logging
 
@@ -29,11 +24,14 @@ from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'SuspiciousHeader',
+    ]
+
 
 log = logging.getLogger('mailman.error')
 
 
-
 @implementer(IRule)
 class SuspiciousHeader:
     """The historical 'suspicious header' rule."""
@@ -48,7 +46,6 @@ class SuspiciousHeader:
                 has_matching_bounce_header(mlist, msg))
 
 
-
 def _parse_matching_header_opt(mlist):
     """Return a list of triples [(field name, regex, line), ...]."""
     # - Blank lines and lines with '#' as first char are skipped.
diff --git a/src/mailman/rules/tests/test_approved.py b/src/mailman/rules/tests/test_approved.py
index 401e26634..62d67c848 100644
--- a/src/mailman/rules/tests/test_approved.py
+++ b/src/mailman/rules/tests/test_approved.py
@@ -17,15 +17,6 @@
 
 """Test the `approved` handler."""
 
-__all__ = [
-    'TestApproved',
-    'TestApprovedNonASCII',
-    'TestApprovedPseudoHeader',
-    'TestApprovedPseudoHeaderMIME',
-    'TestPasswordHashMigration',
-    ]
-
-
 import os
 import unittest
 
@@ -37,7 +28,6 @@ from mailman.testing.helpers import (
 from mailman.testing.layers import ConfigLayer
 
 
-
 class TestApproved(unittest.TestCase):
     """Test the approved handler."""
 
@@ -145,7 +135,6 @@ A message body.
         self.assertFalse(result)
 
 
-
 class TestApprovedPseudoHeader(unittest.TestCase):
     """Test the approved handler."""
 
@@ -278,7 +267,6 @@ X-Approve: not the password
         self.assertFalse('X-Approve' in self._msg.get_payload())
 
 
-
 class TestApprovedPseudoHeaderMIME(unittest.TestCase):
     """Test the approved handler."""
 
@@ -392,7 +380,6 @@ An important message.
         self.assertFalse('X-Approve' in msg.get_payload(1).get_payload())
 
 
-
 class TestApprovedNonASCII(unittest.TestCase):
     """Test the approved handler with non-ascii messages."""
 
@@ -514,7 +501,6 @@ deprecated = roundup_plaintext
                          '{plaintext}super secret')
 
 
-
 class TestApprovedNoTextPlainPart(unittest.TestCase):
     """Test the approved handler with HTML-only messages."""
 
diff --git a/src/mailman/rules/tests/test_moderation.py b/src/mailman/rules/tests/test_moderation.py
index 655e92863..df1658792 100644
--- a/src/mailman/rules/tests/test_moderation.py
+++ b/src/mailman/rules/tests/test_moderation.py
@@ -17,11 +17,6 @@
 
 """Test the `member-moderation` and `nonmember-moderation` rules."""
 
-__all__ = [
-    'TestModeration',
-    ]
-
-
 import unittest
 
 from mailman.app.lifecycle import create_list
@@ -34,7 +29,6 @@ from mailman.testing.layers import ConfigLayer
 from zope.component import getUtility
 
 
-
 class TestModeration(unittest.TestCase):
     """Test the approved handler."""
 
@@ -147,5 +141,6 @@ A message body.
             result = rule.check(self._mlist, msg, msgdata)
             self.assertTrue(result, 'NonmemberModeration rule should hit')
             self.assertIn('moderation_action', msgdata)
-            self.assertEqual(msgdata['moderation_action'], action_name,
+            self.assertEqual(
+                msgdata['moderation_action'], action_name,
                 'Wrong action for {}: {}'.format(address, action_name))
diff --git a/src/mailman/rules/truth.py b/src/mailman/rules/truth.py
index 3189c233a..16b2e1893 100644
--- a/src/mailman/rules/truth.py
+++ b/src/mailman/rules/truth.py
@@ -17,17 +17,15 @@
 
 """A rule which always matches."""
 
-__all__ = [
-    'Truth',
-    ]
-
-
 from mailman.core.i18n import _
 from mailman.interfaces.rules import IRule
 from zope.interface import implementer
 
+__all__ = [
+    'Truth',
+    ]
+
 
-
 @implementer(IRule)
 class Truth:
     """Look for any previous rule match."""
diff --git a/src/mailman/version.py b/src/mailman/version.py
index 32431d756..229bb7fba 100644
--- a/src/mailman/version.py
+++ b/src/mailman/version.py
@@ -23,10 +23,10 @@ CODENAME = 'Between The Wheels'
 
 # And as a hex number in the manner of PY_VERSION_HEX.
 ALPHA = 0xa
-BETA  = 0xb
+BETA  = 0xb                                         # flake8: noqa
 GAMMA = 0xc
 # Release candidates.
-RC    = GAMMA
+RC    = GAMMA                                       # flake8: noqa
 FINAL = 0xf
 
 MAJOR_REV = 3
@@ -37,7 +37,7 @@ REL_LEVEL = ALPHA
 REL_SERIAL = 1
 
 HEX_VERSION = ((MAJOR_REV << 24) | (MINOR_REV << 16) | (MICRO_REV << 8) |
-               (REL_LEVEL << 4)  | (REL_SERIAL << 0))
+               (REL_LEVEL << 4)  | (REL_SERIAL << 0))   # flake8: noqa
 
 
 # queue/*.pck schema version number.