33 files changed, 158 insertions, 383 deletions

diff --git a/setup.py b/setup.py
index 236faa3f5..0a63d225c 100644
--- a/setup.py
+++ b/setup.py
@@ -24,8 +24,8 @@ import sys
 from setuptools import setup, find_packages
 from string import Template
 
-if sys.hexversion < 0x20600f0:
-    print 'Mailman requires at least Python 2.6'
+if sys.hexversion < 0x20700f0:
+    print 'Mailman requires at least Python 2.7'
     sys.exit(1)
 
 
diff --git a/src/mailman/app/tests/test_membership.py b/src/mailman/app/tests/test_membership.py
index 113ae6a52..a22a239b7 100644
--- a/src/mailman/app/tests/test_membership.py
+++ b/src/mailman/app/tests/test_membership.py
@@ -137,17 +137,14 @@ class AddMemberTest(unittest.TestCase):
                    'Anne Person', '123', DeliveryMode.regular,
                    system_preferences.preferred_language,
                    MemberRole.member)
-        try:
+        with self.assertRaises(AlreadySubscribedError) as cm:
             add_member(self._mlist, 'aperson@example.com',
                        'Anne Person', '123', DeliveryMode.regular,
                        system_preferences.preferred_language,
                        MemberRole.member)
-        except AlreadySubscribedError as exc:
-            self.assertEqual(exc.fqdn_listname, 'test@example.com')
-            self.assertEqual(exc.email, 'aperson@example.com')
-            self.assertEqual(exc.role, MemberRole.member)
-        else:
-            raise AssertionError('AlreadySubscribedError expected')
+        self.assertEqual(cm.exception.fqdn_listname, 'test@example.com')
+        self.assertEqual(cm.exception.email, 'aperson@example.com')
+        self.assertEqual(cm.exception.role, MemberRole.member)
 
     def test_add_member_with_different_roles(self):
         # Adding a member twice with different roles is okay.
diff --git a/src/mailman/app/tests/test_subscriptions.py b/src/mailman/app/tests/test_subscriptions.py
index 1c37d4cb9..c4c8f2795 100644
--- a/src/mailman/app/tests/test_subscriptions.py
+++ b/src/mailman/app/tests/test_subscriptions.py
@@ -51,19 +51,13 @@ class TestJoin(unittest.TestCase):
 
     def test_join_user_with_bogus_id(self):
         # When `subscriber` is a missing user id, an exception is raised.
-        try:
+        with self.assertRaises(MissingUserError) as cm:
             self._service.join('test.example.com', uuid.UUID(int=99))
-        except MissingUserError as exc:
-            self.assertEqual(exc.user_id, uuid.UUID(int=99))
-        else:
-            raise AssertionError('MissingUserError expected')
+        self.assertEqual(cm.exception.user_id, uuid.UUID(int=99))
 
     def test_join_user_with_invalid_email_address(self):
         # When `subscriber` is a string that is not an email address, an
         # exception is raised.
-        try:
+        with self.assertRaises(InvalidEmailAddressError) as cm:
             self._service.join('test.example.com', 'bogus')
-        except InvalidEmailAddressError as exc:
-            self.assertEqual(exc.email, 'bogus')
-        else:
-            raise AssertionError('InvalidEmailAddressError expected')
+        self.assertEqual(cm.exception.email, 'bogus')
diff --git a/src/mailman/app/tests/test_templates.py b/src/mailman/app/tests/test_templates.py
index 6dfbd7109..788412a57 100644
--- a/src/mailman/app/tests/test_templates.py
+++ b/src/mailman/app/tests/test_templates.py
@@ -98,49 +98,31 @@ class TestTemplateLoader(unittest.TestCase):
         self.assertEqual(content, 'Test content')
 
     def test_uri_not_found(self):
-        try:
+        with self.assertRaises(urllib2.URLError) as cm:
             self._loader.get('mailman:///missing.txt')
-        except urllib2.URLError as error:
-            self.assertEqual(error.reason, 'No such file')
-        else:
-            raise AssertionError('Exception expected')
+        self.assertEqual(cm.exception.reason, 'No such file')
 
     def test_shorter_url_error(self):
-        try:
+        with self.assertRaises(urllib2.URLError) as cm:
             self._loader.get('mailman:///')
-        except urllib2.URLError as error:
-            self.assertEqual(error.reason, 'No template specified')
-        else:
-            raise AssertionError('Exception expected')
+        self.assertEqual(cm.exception.reason, 'No template specified')
 
     def test_short_url_error(self):
-        try:
+        with self.assertRaises(urllib2.URLError) as cm:
             self._loader.get('mailman://')
-        except urllib2.URLError as error:
-            self.assertEqual(error.reason, 'No template specified')
-        else:
-            raise AssertionError('Exception expected')
+        self.assertEqual(cm.exception.reason, 'No template specified')
 
     def test_bad_language(self):
-        try:
+        with self.assertRaises(urllib2.URLError) as cm:
             self._loader.get('mailman:///xx/demo.txt')
-        except urllib2.URLError as error:
-            self.assertEqual(error.reason, 'Bad language or list name')
-        else:
-            raise AssertionError('Exception expected')
+        self.assertEqual(cm.exception.reason, 'Bad language or list name')
 
     def test_bad_mailing_list(self):
-        try:
+        with self.assertRaises(urllib2.URLError) as cm:
             self._loader.get('mailman:///missing@example.com/demo.txt')
-        except urllib2.URLError as error:
-            self.assertEqual(error.reason, 'Bad language or list name')
-        else:
-            raise AssertionError('Exception expected')
+        self.assertEqual(cm.exception.reason, 'Bad language or list name')
 
     def test_too_many_path_components(self):
-        try:
+        with self.assertRaises(urllib2.URLError) as cm:
             self._loader.get('mailman:///missing@example.com/en/foo/demo.txt')
-        except urllib2.URLError as error:
-            self.assertEqual(error.reason, 'No such file')
-        else:
-            raise AssertionError('Exception expected')
+        self.assertEqual(cm.exception.reason, 'No such file')
diff --git a/src/mailman/chains/tests/test_headers.py b/src/mailman/chains/tests/test_headers.py
index 65a23d891..e8856031c 100644
--- a/src/mailman/chains/tests/test_headers.py
+++ b/src/mailman/chains/tests/test_headers.py
@@ -44,8 +44,6 @@ class TestHeaderChain(unittest.TestCase):
 
     def setUp(self):
         self._mlist = create_list('test@example.com')
-        # Python 2.6 does not have assertListEqual().
-        self._leq = getattr(self, 'assertListEqual', self.assertEqual)
 
     @configuration('antispam', header_checks="""
     Foo: a+
@@ -71,7 +69,7 @@ class TestHeaderChain(unittest.TestCase):
                 self.assertEqual(link.rule.name[:13], 'header-match-')
                 self.assertEqual(link.action, LinkAction.defer)
                 post_checks.append((link.rule.header, link.rule.pattern))
-        self._leq(post_checks, [
+        self.assertListEqual(post_checks, [
             ('Foo', 'a+'),
             ('Bar', 'bb?'),
             ])
@@ -103,7 +101,7 @@ class TestHeaderChain(unittest.TestCase):
                 self.assertEqual(link.rule.name[:13], 'header-match-')
                 self.assertEqual(link.action, LinkAction.defer)
                 post_checks.append((link.rule.header, link.rule.pattern))
-        self._leq(post_checks, [
+        self.assertListEqual(post_checks, [
             ('Foo', 'foo'),
             ('Bar', 'bar'),
             ])
diff --git a/src/mailman/core/errors.py b/src/mailman/core/errors.py
index 95a318ca6..42b536d46 100644
--- a/src/mailman/core/errors.py
+++ b/src/mailman/core/errors.py
@@ -90,6 +90,12 @@ def _(s):
 class HandlerError(MailmanError):
     """Base class for all handler errors."""
 
+    def __init__(self, message=None):
+        self.message = message
+
+    def __str__(self):
+        return self.message
+
 
 class HoldMessage(HandlerError):
     """Base class for all message-being-held short circuits."""
diff --git a/src/mailman/core/logging.py b/src/mailman/core/logging.py
index af04b58d1..2442d4913 100644
--- a/src/mailman/core/logging.py
+++ b/src/mailman/core/logging.py
@@ -40,8 +40,8 @@ _handlers = {}
 
 
 
-# XXX I would love to simplify things and use Python 2.6's WatchedFileHandler,
-# but there are two problems.  First, it's more difficult to handle the test
+# XXX I would love to simplify things and use Python's WatchedFileHandler, but
+# there are two problems.  First, it's more difficult to handle the test
 # suite's need to reopen the file handler to a different path.  Does
 # zope.testing's logger support fix this?
 #
diff --git a/src/mailman/core/tests/test_runner.py b/src/mailman/core/tests/test_runner.py
index ad2548adc..80a503f5d 100644
--- a/src/mailman/core/tests/test_runner.py
+++ b/src/mailman/core/tests/test_runner.py
@@ -81,7 +81,7 @@ Message-ID: <ant>
         self.assertEqual(event.message['message-id'], '<ant>')
         self.assertEqual(event.metadata['listname'], 'test@example.com')
         self.assertTrue(isinstance(event.error, RuntimeError))
-        self.assertEqual(event.error.message, 'borked')
+        self.assertEqual(str(event.error), 'borked')
         self.assertTrue(isinstance(event.runner, CrashingRunner))
         # The message should also have ended up in the shunt queue.
         shunted = get_queue_messages('shunt')
diff --git a/src/mailman/docs/INTRODUCTION.rst b/src/mailman/docs/INTRODUCTION.rst
index 11d13c239..8e334c08a 100644
--- a/src/mailman/docs/INTRODUCTION.rst
+++ b/src/mailman/docs/INTRODUCTION.rst
@@ -82,7 +82,7 @@ lists and archives, etc., are available at:
 Requirements
 ============
 
-Mailman 3.0 requires `Python 2.6`_ or newer.
+Mailman 3.0 requires `Python 2.7`_ or newer.
 
 
 .. _`GNU Mailman`: http://www.list.org
@@ -90,4 +90,4 @@ Mailman 3.0 requires `Python 2.6`_ or newer.
 .. _`Getting Started`: START.html
 .. _Python: http://www.python.org
 .. _FAQ: http://wiki.list.org/display/DOC/Frequently+Asked+Questions
-.. _`Python 2.6`: http://www.python.org/download/releases/2.6.6/
+.. _`Python 2.7`: http://www.python.org/download/releases/2.7.3/
diff --git a/src/mailman/docs/NEWS.rst b/src/mailman/docs/NEWS.rst
index 11f52a3de..892cc52c4 100644
--- a/src/mailman/docs/NEWS.rst
+++ b/src/mailman/docs/NEWS.rst
@@ -12,6 +12,11 @@ Here is a history of user visible changes to Mailman.
 ==========================
 (2012-XX-XX)
 
+Compatibility
+-------------
+ * Python 2.7 is not required.  Python 2.6 is no longer officially supported.
+   LP: #1073506
+
 REST
 ----
  * Add list_id to JSON representation for a mailing list (given by Jimmy
diff --git a/src/mailman/docs/START.rst b/src/mailman/docs/START.rst
index da76feae0..dbf4966c4 100644
--- a/src/mailman/docs/START.rst
+++ b/src/mailman/docs/START.rst
@@ -32,14 +32,13 @@ mailman-developers@python.org mailing list.
 Requirements
 ============
 
-Python 2.6 or 2.7 is required.  It can either be the default 'python' on your
-$PATH or it can be accessible via the ``python2.6`` or ``python2.7`` binary.
+Python 2.7 is required.  It can either be the default 'python' on your
+$PATH or it can be accessible via the ``python2.7`` binary.
 If your operating system does not include Python, see http://www.python.org
 downloading and installing it from source.  Python 3 is not yet supported.
 
 In this documentation, a bare ``python`` refers to the Python executable used
-to invoke ``bootstrap.py``, which might be ``python2.6`` or ``python2.7``, as
-well as the system ``python`` or an absolute path.
+to invoke ``bootstrap.py``.
 
 Mailman 3 is now based on the `zc.buildout`_ infrastructure, which greatly
 simplifies building and testing Mailman.
diff --git a/src/mailman/docs/STYLEGUIDE.rst b/src/mailman/docs/STYLEGUIDE.rst
index b744c6557..29661701b 100644
--- a/src/mailman/docs/STYLEGUIDE.rst
+++ b/src/mailman/docs/STYLEGUIDE.rst
@@ -15,7 +15,7 @@ http://barry.warsaw.us/software/STYLEGUIDE.txt
 This document contains a style guide for Python programming, as used in GNU
 Mailman.  `PEP 8`_ is the basis for this style guide so it's recommendations
 should be followed except for the differences outlined here.  This document
-assumes the use of Python 2.6 or 2.7, but not (yet) Python 3.
+assumes the use of Python 2.7, but not (yet) Python 3.
 
 * After file comments (e.g. license block), add a ``__metaclass__`` definition
   so that all classes will be new-style.  Following that, add an ``__all__``
diff --git a/src/mailman/docs/WebUIin5.rst b/src/mailman/docs/WebUIin5.rst
index 56f2df9fb..6419e4752 100644
--- a/src/mailman/docs/WebUIin5.rst
+++ b/src/mailman/docs/WebUIin5.rst
@@ -7,8 +7,8 @@ Mailman 3's web UI, called Postorius.  If all goes as planned, you should be
 done within 5 minutes.  This has been tested on Ubuntu 11.04.
 
 In order to download the components necessary you need to have the `Bazaar`_
-version control system installed on your system.  Mailman and mailman.client
-need at least Python version 2.6.
+version control system installed on your system.  Mailman requires Python 2.7,
+while mailman.client needs at least Python version 2.6.
 
 It's probably a good idea to set up a virtual Python environment using
 `virtualenv`_.  `Here is a brief HOWTO`_.
diff --git a/src/mailman/email/message.py b/src/mailman/email/message.py
index dcea82425..601d4f839 100644
--- a/src/mailman/email/message.py
+++ b/src/mailman/email/message.py
@@ -219,11 +219,7 @@ class UserNotification(Message):
         if mlist is not None:
             enqueue_kws['listname'] = mlist.fqdn_listname
         enqueue_kws.update(_kws)
-        # Keywords must be strings in Python 2.6.
-        str_keywords = dict()
-        for key, val in enqueue_kws.items():
-            str_keywords[str(key)] = val
-        virginq.enqueue(self, **str_keywords)
+        virginq.enqueue(self, **enqueue_kws)
 
 
 
diff --git a/src/mailman/handlers/tests/test_mimedel.py b/src/mailman/handlers/tests/test_mimedel.py
index 6ca34b17b..74790fbf7 100644
--- a/src/mailman/handlers/tests/test_mimedel.py
+++ b/src/mailman/handlers/tests/test_mimedel.py
@@ -37,8 +37,7 @@ from mailman.interfaces.action import FilterAction
 from mailman.interfaces.member import MemberRole
 from mailman.interfaces.usermanager import IUserManager
 from mailman.testing.helpers import (
-    LogFileMark,
-    get_queue_messages,
+    LogFileMark, configuration, get_queue_messages,
     specialized_message_from_string as mfs)
 from mailman.testing.layers import ConfigLayer
 
@@ -71,25 +70,17 @@ Message-ID: <ant>
 
     def test_dispose_discard(self):
         self._mlist.filter_action = FilterAction.discard
-        try:
+        with self.assertRaises(errors.DiscardMessage) as cm:
             mime_delete.dispose(self._mlist, self._msg, {}, 'discarding')
-        except errors.DiscardMessage as error:
-            pass
-        else:
-            raise AssertionError('DiscardMessage exception expected')
-        self.assertEqual(error.message, 'discarding')
+        self.assertEqual(cm.exception.message, 'discarding')
         # There should be no messages in the 'bad' queue.
         self.assertEqual(len(get_queue_messages('bad')), 0)
 
     def test_dispose_bounce(self):
         self._mlist.filter_action = FilterAction.reject
-        try:
+        with self.assertRaises(errors.RejectMessage) as cm:
             mime_delete.dispose(self._mlist, self._msg, {}, 'rejecting')
-        except errors.RejectMessage as error:
-            pass
-        else:
-            raise AssertionError('RejectMessage exception expected')
-        self.assertEqual(error.message, 'rejecting')
+        self.assertEqual(cm.exception.message, 'rejecting')
         # There should be no messages in the 'bad' queue.
         self.assertEqual(len(get_queue_messages('bad')), 0)
 
@@ -103,13 +94,9 @@ Message-ID: <ant>
         self._mlist.subscribe(bart, MemberRole.moderator)
         # Now set the filter action and dispose the message.
         self._mlist.filter_action = FilterAction.forward
-        try:
+        with self.assertRaises(errors.DiscardMessage) as cm:
             mime_delete.dispose(self._mlist, self._msg, {}, 'forwarding')
-        except errors.DiscardMessage as error:
-            pass
-        else:
-            raise AssertionError('DiscardMessage exception expected')
-        self.assertEqual(error.message, 'forwarding')
+        self.assertEqual(cm.exception.message, 'forwarding')
         # There should now be a multipart message in the virgin queue destined
         # for the mailing list owners.
         messages = get_queue_messages('virgin')
@@ -143,46 +130,28 @@ message.
         self.assertEqual(original['subject'], 'A disposable message')
         self.assertEqual(original['message-id'], '<ant>')
 
+    @configuration('mailman', filtered_messages_are_preservable='no')
     def test_dispose_non_preservable(self):
         # Two actions can happen here, depending on a site-wide setting.  If
         # the site owner has indicated that filtered messages cannot be
         # preserved, then this is the same as discarding them.
         self._mlist.filter_action = FilterAction.preserve
-        config.push('non-preservable', """
-        [mailman]
-        filtered_messages_are_preservable: no
-        """)
-        try:
+        with self.assertRaises(errors.DiscardMessage) as cm:
             mime_delete.dispose(self._mlist, self._msg, {}, 'not preserved')
-        except errors.DiscardMessage as error:
-            pass
-        else:
-            raise AssertionError('DiscardMessage exception expected')
-        finally:
-            config.pop('non-preservable')
-        self.assertEqual(error.message, 'not preserved')
+        self.assertEqual(cm.exception.message, 'not preserved')
         # There should be no messages in the 'bad' queue.
         self.assertEqual(len(get_queue_messages('bad')), 0)
 
+    @configuration('mailman', filtered_messages_are_preservable='yes')
     def test_dispose_preservable(self):
         # Two actions can happen here, depending on a site-wide setting.  If
         # the site owner has indicated that filtered messages can be
         # preserved, then this is similar to discarding the message except
         # that a copy is preserved in the 'bad' queue.
         self._mlist.filter_action = FilterAction.preserve
-        config.push('preservable', """
-        [mailman]
-        filtered_messages_are_preservable: yes
-        """)
-        try:
+        with self.assertRaises(errors.DiscardMessage) as cm:
             mime_delete.dispose(self._mlist, self._msg, {}, 'preserved')
-        except errors.DiscardMessage as error:
-            pass
-        else:
-            raise AssertionError('DiscardMessage exception expected')
-        finally:
-            config.pop('preservable')
-        self.assertEqual(error.message, 'preserved')
+        self.assertEqual(cm.exception.message, 'preserved')
         # There should be no messages in the 'bad' queue.
         messages = get_queue_messages('bad')
         self.assertEqual(len(messages), 1)
@@ -200,13 +169,9 @@ message.
                        FilterAction.defer):
             self._mlist.filter_action = action
             mark = LogFileMark('mailman.error')
-            try:
+            with self.assertRaises(errors.DiscardMessage) as cm:
                 mime_delete.dispose(self._mlist, self._msg, {}, 'bad action')
-            except errors.DiscardMessage as error:
-                pass
-            else:
-                raise AssertionError('DiscardMessage exception expected')
-            self.assertEqual(error.message, 'bad action')
+            self.assertEqual(cm.exception.message, 'bad action')
             line = mark.readline()[:-1]
             self.assertTrue(line.endswith(
                 '{0} invalid FilterAction: test@example.com.  '
diff --git a/src/mailman/interfaces/address.py b/src/mailman/interfaces/address.py
index 54bf6b283..7df15b91f 100644
--- a/src/mailman/interfaces/address.py
+++ b/src/mailman/interfaces/address.py
@@ -47,11 +47,7 @@ class EmailError(MailmanError):
         self.email = email
 
     def __str__(self):
-        # This is a workaround for Python 2.6 support.  When self.email
-        # contains non-ascii characters, this will cause unprintable output in
-        # doctests.  Python 2.7 can handle it but we haven't dropped support
-        # for 2.6 yet.
-        return self.email.encode('us-ascii', 'backslashreplace')
+        return self.email
 
 
 class AddressError(MailmanError):
diff --git a/src/mailman/model/docs/listmanager.rst b/src/mailman/model/docs/listmanager.rst
index 380fe7704..41450b15d 100644
--- a/src/mailman/model/docs/listmanager.rst
+++ b/src/mailman/model/docs/listmanager.rst
@@ -126,8 +126,7 @@ address components.
     test_3@example.com
     test_4@example.com
 
-    >>> for list_name, mail_host in sorted(list_manager.name_components,
-    ...                                    key=lambda (name, host): name):
+    >>> for list_name, mail_host in sorted(list_manager.name_components):
     ...     print list_name, '@', mail_host
     test   @ example.com
     test_3 @ example.com
diff --git a/src/mailman/rest/tests/test_addresses.py b/src/mailman/rest/tests/test_addresses.py
index 01ce710b2..35a19f77f 100644
--- a/src/mailman/rest/tests/test_addresses.py
+++ b/src/mailman/rest/tests/test_addresses.py
@@ -48,34 +48,24 @@ class TestAddresses(unittest.TestCase):
 
     def test_membership_of_missing_address(self):
         # Try to get the memberships of a missing address.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/addresses/'
                      'nobody@example.com/memberships')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError 404')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_verify_a_missing_address(self):
         # POSTing to the 'verify' sub-resource returns a 404.
-        try:
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/addresses/'
                      'nobody@example.com/verify', {})
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError 404')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_unverify_a_missing_address(self):
         # POSTing to the 'unverify' sub-resource returns a 404.
-        try:
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/addresses/'
                      'nobody@example.com/unverify', {})
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError 404')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_verify_already_verified(self):
         # It's okay to verify an already verified; it just doesn't change the
@@ -105,23 +95,17 @@ class TestAddresses(unittest.TestCase):
         with transaction():
             anne = getUtility(IUserManager).create_address('anne@example.com')
             self.assertEqual(anne.verified_on, None)
-        try:
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/addresses/'
                      'anne@example.com/verify/foo', {})
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-        else:
-            raise AssertionError('Expected HTTPError 400')
+        self.assertEqual(cm.exception.code, 400)
 
     def test_unverify_bad_request(self):
         # Too many segments after /verify.
         with transaction():
             anne = getUtility(IUserManager).create_address('anne@example.com')
             self.assertEqual(anne.verified_on, None)
-        try:
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/addresses/'
                      'anne@example.com/unverify/foo', {})
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-        else:
-            raise AssertionError('Expected HTTPError 400')
+        self.assertEqual(cm.exception.code, 400)
diff --git a/src/mailman/rest/tests/test_domains.py b/src/mailman/rest/tests/test_domains.py
index a86768481..dea6a0aa6 100644
--- a/src/mailman/rest/tests/test_domains.py
+++ b/src/mailman/rest/tests/test_domains.py
@@ -47,24 +47,16 @@ class TestDomains(unittest.TestCase):
 
     def test_bogus_endpoint_extension(self):
         # /domains/<domain>/lists/<anything> is not a valid endpoint.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/domains/example.com'
                      '/lists/wrong')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 400)
 
     def test_bogus_endpoint(self):
         # /domains/<domain>/<!lists> does not exist.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/domains/example.com/wrong')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_lists_are_deleted_when_domain_is_deleted(self):
         # /domains/<domain> DELETE removes all associated mailing lists.
diff --git a/src/mailman/rest/tests/test_lists.py b/src/mailman/rest/tests/test_lists.py
index cd0ebaf8e..9686ce6a8 100644
--- a/src/mailman/rest/tests/test_lists.py
+++ b/src/mailman/rest/tests/test_lists.py
@@ -46,47 +46,31 @@ class TestListsMissing(unittest.TestCase):
 
     def test_missing_list_roster_member_404(self):
         # /lists/<missing>/roster/member gives 404
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/lists/missing@example.com'
                      '/roster/member')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_missing_list_roster_owner_404(self):
         # /lists/<missing>/roster/owner gives 404
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/lists/missing@example.com'
                      '/roster/owner')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_missing_list_roster_moderator_404(self):
         # /lists/<missing>/roster/member gives 404
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/lists/missing@example.com'
                      '/roster/moderator')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_missing_list_configuration_404(self):
         # /lists/<missing>/config gives 404
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api(
                 'http://localhost:9001/3.0/lists/missing@example.com/config')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
 
 
 
diff --git a/src/mailman/rest/tests/test_membership.py b/src/mailman/rest/tests/test_membership.py
index 18469e537..3bbe821ac 100644
--- a/src/mailman/rest/tests/test_membership.py
+++ b/src/mailman/rest/tests/test_membership.py
@@ -50,41 +50,29 @@ class TestMembership(unittest.TestCase):
 
     def test_try_to_join_missing_list(self):
         # A user tries to join a non-existent list.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/members', {
                 'list_id': 'missing.example.com',
                 'subscriber': 'nobody@example.com',
                 })
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-            self.assertEqual(exc.msg, 'No such list')
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 400)
+        self.assertEqual(cm.exception.msg, 'No such list')
 
     def test_try_to_leave_missing_list(self):
         # A user tries to leave a non-existent list.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/lists/missing@example.com'
                      '/member/nobody@example.com',
                      method='DELETE')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-            self.assertEqual(exc.msg, '404 Not Found')
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
+        self.assertEqual(cm.exception.msg, '404 Not Found')
 
     def test_try_to_leave_list_with_bogus_address(self):
         # Try to leave a mailing list using an invalid membership address.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/members/1', method='DELETE')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-            self.assertEqual(exc.msg, '404 Not Found')
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
+        self.assertEqual(cm.exception.msg, '404 Not Found')
 
     def test_try_to_leave_a_list_twice(self):
         with transaction():
@@ -96,45 +84,34 @@ class TestMembership(unittest.TestCase):
         # content.
         self.assertEqual(content, None)
         self.assertEqual(response.status, 204)
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api(url, method='DELETE')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-            self.assertEqual(exc.msg, '404 Not Found')
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
+        self.assertEqual(cm.exception.msg, '404 Not Found')
 
     def test_try_to_join_a_list_twice(self):
         with transaction():
             anne = self._usermanager.create_address('anne@example.com')
             self._mlist.subscribe(anne)
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/members', {
                 'list_id': 'test.example.com',
                 'subscriber': 'anne@example.com',
                 })
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 409)
-            self.assertEqual(exc.msg, 'Member already subscribed')
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 409)
+        self.assertEqual(cm.exception.msg, 'Member already subscribed')
 
     def test_join_with_invalid_delivery_mode(self):
-        try:
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/members', {
                 'list_id': 'test.example.com',
                 'subscriber': 'anne@example.com',
                 'display_name': 'Anne Person',
                 'delivery_mode': 'invalid-mode',
                 })
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-            self.assertEqual(exc.msg,
-                             'Cannot convert parameters: delivery_mode')
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 400)
+        self.assertEqual(cm.exception.msg,
+                         'Cannot convert parameters: delivery_mode')
 
     def test_join_email_contains_slash(self):
         content, response = call_api('http://localhost:9001/3.0/members', {
@@ -196,47 +173,31 @@ class TestMembership(unittest.TestCase):
 
     def test_get_nonexistent_member(self):
         # /members/<bogus> returns 404
-        try:
-            # For Python 2.6
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/members/bogus')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_patch_nonexistent_member(self):
         # /members/<missing> PATCH returns 404
-        try:
-            # For Python 2.6
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/members/801', method='PATCH')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_patch_member_bogus_attribute(self):
         # /members/<id> PATCH 'bogus' returns 400
         with transaction():
             anne = self._usermanager.create_address('anne@example.com')
             self._mlist.subscribe(anne)
-        try:
-            # For Python 2.6
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/members/1', {
                      'powers': 'super',
                      }, method='PATCH')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-            self.assertEqual(exc.msg, 'Unexpected parameters: powers')
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 400)
+        self.assertEqual(cm.exception.msg, 'Unexpected parameters: powers')
 
     def test_member_all_without_preferences(self):
         # /members/<id>/all should return a 404 when it isn't trailed by
         # `preferences`
-        try:
-            # For Python 2.6
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/members/1/all')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
diff --git a/src/mailman/rest/tests/test_moderation.py b/src/mailman/rest/tests/test_moderation.py
index dfcedef05..2ee796c87 100644
--- a/src/mailman/rest/tests/test_moderation.py
+++ b/src/mailman/rest/tests/test_moderation.py
@@ -56,24 +56,16 @@ Something else.
 
     def test_not_found(self):
         # When a bogus mailing list is given, 404 should result.
-        try:
-            # For Python 2.6
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/lists/bee@example.com/held')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
 
     def test_bad_request_id(self):
         # Bad request when request_id is not an integer.
-        try:
-            # For Python 2.6
+        with self.assertRaises(HTTPError) as cm:
             call_api(
                 'http://localhost:9001/3.0/lists/ant@example.com/held/bogus')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 400)
 
     def test_subscription_request_as_held_message(self):
         # Provide the request id of a subscription request using the held
@@ -85,12 +77,9 @@ Something else.
             DeliveryMode.regular, 'en')
         config.db.store.commit()
         url = 'http://localhost:9001/3.0/lists/ant@example.com/held/{0}'
-        try:
+        with self.assertRaises(HTTPError) as cm:
             call_api(url.format(subscribe_id))
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
         # But using the held_id returns a valid response.
         response, content = call_api(url.format(held_id))
         self.assertEqual(response['key'], '<alpha>')
@@ -99,10 +88,7 @@ Something else.
         # POSTing to a held message with a bad action.
         held_id = hold_message(self._mlist, self._msg)
         url = 'http://localhost:9001/3.0/lists/ant@example.com/held/{0}'
-        try:
+        with self.assertRaises(HTTPError) as cm:
             call_api(url.format(held_id), {'action': 'bogus'})
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-            self.assertEqual(exc.msg, 'Cannot convert parameters: action')
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 400)
+        self.assertEqual(cm.exception.msg, 'Cannot convert parameters: action')
diff --git a/src/mailman/rest/tests/test_root.py b/src/mailman/rest/tests/test_root.py
index 90d30bd80..4a9ba0dd1 100644
--- a/src/mailman/rest/tests/test_root.py
+++ b/src/mailman/rest/tests/test_root.py
@@ -38,38 +38,25 @@ class TestSystem(unittest.TestCase):
 
     def test_system_url_too_long(self):
         # /system/foo/bar is not allowed.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/system/foo/bar')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 400)
 
     def test_system_url_not_preferences(self):
         # /system/foo where `foo` is not `preferences`.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/system/foo')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 400)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 400)
 
     def test_system_preferences_are_read_only(self):
         # /system/preferences are read-only.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/system/preferences', {
                      'acknowledge_posts': True,
                      }, method='PATCH')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 405)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 405)
         # /system/preferences are read-only.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/system/preferences', {
                 'acknowledge_posts': False,
                 'delivery_mode': 'regular',
@@ -79,7 +66,4 @@ class TestSystem(unittest.TestCase):
                 'receive_list_copy': True,
                 'receive_own_postings': True,
                 }, method='PUT')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 405)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 405)
diff --git a/src/mailman/rest/tests/test_users.py b/src/mailman/rest/tests/test_users.py
index 301027885..4595c69d8 100644
--- a/src/mailman/rest/tests/test_users.py
+++ b/src/mailman/rest/tests/test_users.py
@@ -45,10 +45,6 @@ class TestUsers(unittest.TestCase):
 
     def test_delete_bogus_user(self):
         # Try to delete a user that does not exist.
-        try:
-            # For Python 2.6.
+        with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/users/99', method='DELETE')
-        except HTTPError as exc:
-            self.assertEqual(exc.code, 404)
-        else:
-            raise AssertionError('Expected HTTPError')
+        self.assertEqual(cm.exception.code, 404)
diff --git a/src/mailman/rules/administrivia.py b/src/mailman/rules/administrivia.py
index 4c49e4ff2..6f5f41cd3 100644
--- a/src/mailman/rules/administrivia.py
+++ b/src/mailman/rules/administrivia.py
@@ -84,7 +84,7 @@ class Administrivia:
                 if len(line) == 0:
                     continue
                 lineno += 1
-                if lineno > config.mailman.email_commands_max_lines:
+                if lineno > int(config.mailman.email_commands_max_lines):
                     break
                 lines_to_check.append(line)
             # Only look at the first text/plain part.
diff --git a/src/mailman/runners/digest.py b/src/mailman/runners/digest.py
index 99710dff5..f87dd4e76 100644
--- a/src/mailman/runners/digest.py
+++ b/src/mailman/runners/digest.py
@@ -318,9 +318,9 @@ class DigestRunner(Runner):
         """See `IRunner`."""
         volume = msgdata['volume']
         digest_number = msgdata['digest_number']
-        with nested(Mailbox(msgdata['digest_path']),
-                    _.using(mlist.preferred_language.code)) as (mailbox,
-                                                                language_code):
+        # Backslashes make me cry.
+        with Mailbox(msgdata['digest_path']) as mailbox, \
+             _.using(mlist.preferred_language.code):
             # Create the digesters.
             mime_digest = MIMEDigester(mlist, volume, digest_number)
             rfc1153_digest = RFC1153Digester(mlist, volume, digest_number)
@@ -354,7 +354,7 @@ class DigestRunner(Runner):
         # receive.
         digest_members = set(mlist.digest_members.members)
         for member in digest_members:
-            if member.delivery_status <> DeliveryStatus.enabled:
+            if member.delivery_status is not DeliveryStatus.enabled:
                 continue
             # Send the digest to the case-preserved address of the digest
             # members.
diff --git a/src/mailman/runners/tests/test_confirm.py b/src/mailman/runners/tests/test_confirm.py
index 62171979c..78f6a382c 100644
--- a/src/mailman/runners/tests/test_confirm.py
+++ b/src/mailman/runners/tests/test_confirm.py
@@ -28,6 +28,7 @@ __all__ = [
 import unittest
 
 from datetime import datetime
+from email.iterators import body_line_iterator
 from zope.component import getUtility
 
 from mailman.app.lifecycle import create_list
@@ -37,7 +38,6 @@ from mailman.interfaces.registrar import IRegistrar
 from mailman.interfaces.usermanager import IUserManager
 from mailman.runners.command import CommandRunner
 from mailman.testing.helpers import (
-    body_line_iterator,
     get_queue_messages,
     make_testable_runner,
     specialized_message_from_string as mfs)
diff --git a/src/mailman/runners/tests/test_join.py b/src/mailman/runners/tests/test_join.py
index a584fd2c2..41adcc450 100644
--- a/src/mailman/runners/tests/test_join.py
+++ b/src/mailman/runners/tests/test_join.py
@@ -28,6 +28,7 @@ __all__ = [
 
 import unittest
 
+from email.iterators import body_line_iterator
 from zope.component import getUtility
 
 from mailman.app.lifecycle import create_list
@@ -38,10 +39,7 @@ from mailman.interfaces.subscriptions import ISubscriptionService
 from mailman.interfaces.usermanager import IUserManager
 from mailman.runners.command import CommandRunner
 from mailman.testing.helpers import (
-    body_line_iterator,
-    get_queue_messages,
-    make_testable_runner,
-    reset_the_world,
+    get_queue_messages, make_testable_runner, reset_the_world,
     specialized_message_from_string as mfs)
 from mailman.testing.layers import ConfigLayer
 
diff --git a/src/mailman/runners/tests/test_lmtp.py b/src/mailman/runners/tests/test_lmtp.py
index 46d4ed986..a502c317d 100644
--- a/src/mailman/runners/tests/test_lmtp.py
+++ b/src/mailman/runners/tests/test_lmtp.py
@@ -53,22 +53,19 @@ class TestLMTP(unittest.TestCase):
 
     def test_message_id_required(self):
         # The message is rejected if it does not have a Message-ID header.
-        try:
+        with self.assertRaises(smtplib.SMTPDataError) as cm:
             self._lmtp.sendmail('anne@example.com', ['test@example.com'], """\
 From: anne@example.com
 To: test@example.com
 Subject: This has no Message-ID header
 
 """)
-        except smtplib.SMTPDataError as error:
-            pass
-        else:
-            raise AssertionError('SMTPDataError expected')
         # LMTP returns a 550: Requested action not taken: mailbox unavailable
         # (e.g., mailbox not found, no access, or command rejected for policy
         # reasons)
-        self.assertEqual(error.smtp_code, 550)
-        self.assertEqual(error.smtp_error, 'No Message-ID header provided')
+        self.assertEqual(cm.exception.smtp_code, 550)
+        self.assertEqual(cm.exception.smtp_error, 
+                         'No Message-ID header provided')
 
     def test_message_id_hash_is_added(self):
         self._lmtp.sendmail('anne@example.com', ['test@example.com'], """\
diff --git a/src/mailman/styles/tests/test_styles.py b/src/mailman/styles/tests/test_styles.py
index 990ce541f..a2ffc931f 100644
--- a/src/mailman/styles/tests/test_styles.py
+++ b/src/mailman/styles/tests/test_styles.py
@@ -63,28 +63,16 @@ class TestStyle(unittest.TestCase):
         # Registering a style with the same name as a previous style raises an
         # exception.
         self.manager.register(DummyStyle())
-        try:
-            self.manager.register(DummyStyle())
-        except DuplicateStyleError:
-            pass
-        else:
-            raise AssertionError('DuplicateStyleError exception expected')
+        self.assertRaises(DuplicateStyleError,
+                          self.manager.register, DummyStyle())
 
     def test_register_a_non_style(self):
         # You can't register something that doesn't implement the IStyle
         # interface.
-        try:
-            self.manager.register(object())
-        except DoesNotImplement:
-            pass
-        else:
-            raise AssertionError('DoesNotImplement exception expected')
+        self.assertRaises(DoesNotImplement,
+                          self.manager.register, object())
 
     def test_unregister_a_non_registered_style(self):
         # You cannot unregister a style that hasn't yet been registered.
-        try:
-            self.manager.unregister(DummyStyle())
-        except KeyError:
-            pass
-        else:
-            raise AssertionError('KeyError expected')
+        self.assertRaises(KeyError,
+                          self.manager.unregister, DummyStyle())
diff --git a/src/mailman/testing/helpers.py b/src/mailman/testing/helpers.py
index 054dd4ff7..99f4b8961 100644
--- a/src/mailman/testing/helpers.py
+++ b/src/mailman/testing/helpers.py
@@ -249,8 +249,8 @@ def get_lmtp_client(quiet=False):
             if not quiet:
                 print(response)
             return lmtp
-        except socket.error as error:
-            if error[0] == errno.ECONNREFUSED:
+        except IOError as error:
+            if error.errno == errno.ECONNREFUSED:
                 time.sleep(0.1)
             else:
                 raise
@@ -284,8 +284,8 @@ def wait_for_webservice():
         try:
             socket.socket().connect((config.webservice.hostname,
                                     int(config.webservice.port)))
-        except socket.error as error:
-            if error[0] == errno.ECONNREFUSED:
+        except IOError as error:
+            if error.errno == errno.ECONNREFUSED:
                 time.sleep(0.1)
             else:
                 raise
@@ -515,19 +515,3 @@ class LogFileMark:
         with open(self._filename) as fp:
             fp.seek(self._filepos)
             return fp.readline()
-
-
-
-# In Python 2.6, body_line_iterator() uses a cStringIO.StringIO() which cannot
-# handle unicode.  In Python 2.7 this works fine.  I hate version checks but
-# this is the easiest way to handle it.  OTOH, we could just use the manual
-# way for all Python versions instead.
-import sys
-if sys.hexversion >= 0x2070000:
-    from email.iterators import body_line_iterator
-else:
-    def body_line_iterator(msg, decode=False):
-        payload = msg.get_payload(decode=decode)
-        bytes_payload = payload.encode('utf-8')
-        for line in bytes_payload.splitlines():
-            yield line
diff --git a/src/mailman/utilities/string.py b/src/mailman/utilities/string.py
index 7470bd476..cd3adc536 100644
--- a/src/mailman/utilities/string.py
+++ b/src/mailman/utilities/string.py
@@ -60,19 +60,7 @@ def expand(template, substitutions, template_class=Template):
     :return: The substituted string.
     :rtype: string
     """
-    # Python 2.6 requires ** dictionaries to have str, not unicode keys, so
-    # convert as necessary.  Note that string.Template uses **.  For our
-    # purposes, keys should always be ascii.  Values though can be anything.
-    cooked = substitutions.__class__()
-    for key in substitutions:
-        if isinstance(key, unicode):
-            key = key.encode('ascii')
-        cooked[key] = substitutions[key]
-    try:
-        return template_class(template).safe_substitute(cooked)
-    except (TypeError, ValueError):
-        # The template is really screwed up.
-        log.exception('broken template: %s', template)
+    return template_class(template).safe_substitute(substitutions)
 
 
 
diff --git a/src/mailman/utilities/tests/test_templates.py b/src/mailman/utilities/tests/test_templates.py
index d205eef34..8e335f69b 100644
--- a/src/mailman/utilities/tests/test_templates.py
+++ b/src/mailman/utilities/tests/test_templates.py
@@ -224,13 +224,9 @@ class TestFind(unittest.TestCase):
         self.assertEqual(self.fp.read(), 'List template')
 
     def test_template_not_found(self):
-        # Python 2.6 compatibility.
-        try:
+        with self.assertRaises(TemplateNotFoundError) as cm:
             find('missing.txt', self.mlist)
-        except TemplateNotFoundError as error:
-            self.assertEqual(error.template_file, 'missing.txt')
-        else:
-            raise AssertionError('TemplateNotFoundError expected')
+        self.assertEqual(cm.exception.template_file, 'missing.txt')