14 files changed, 429 insertions, 441 deletions

diff --git a/src/mailman/rest/docs/basic.rst b/src/mailman/rest/docs/basic.rst
index e1a712980..1f8084ecd 100644
--- a/src/mailman/rest/docs/basic.rst
+++ b/src/mailman/rest/docs/basic.rst
@@ -9,17 +9,14 @@ credentials, and the version of the API you wish to speak to.
 Credentials
 ===========
 
-When the `Authorization` header contains the proper credentials, the request
+If you include the proper basic authorization credentials, the request
 succeeds.
 
-    >>> from httplib2 import Http
-    >>> headers = {
-    ...     'Content-Type': 'application/x-www-form-urlencode',
-    ...     'Authorization': 'Basic cmVzdGFkbWluOnJlc3RwYXNz',
-    ...     }
-    >>> url = 'http://localhost:9001/3.0/system/versions'
-    >>> response, content = Http().request(url, 'GET', None, headers)
-    >>> print(response.status)
+    >>> import requests
+    >>> response = requests.get(
+    ...     'http://localhost:9001/3.0/system/versions',
+    ...     auth=('restadmin', 'restpass'))
+    >>> print(response.status_code)
     200
 
 
diff --git a/src/mailman/rest/tests/test_addresses.py b/src/mailman/rest/tests/test_addresses.py
index d70ad5c84..2f9774799 100644
--- a/src/mailman/rest/tests/test_addresses.py
+++ b/src/mailman/rest/tests/test_addresses.py
@@ -59,9 +59,9 @@ class TestAddresses(unittest.TestCase):
     def test_membership_of_address_with_no_user(self):
         with transaction():
             getUtility(IUserManager).create_address('anne@example.com')
-        response, content = call_api(
+        json, content = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com/memberships')
-        self.assertEqual(response['total_size'], 0)
+        self.assertEqual(json['total_size'], 0)
 
     def test_verify_a_missing_address(self):
         # POSTing to the 'verify' sub-resource returns a 404.
@@ -84,9 +84,9 @@ class TestAddresses(unittest.TestCase):
         with transaction():
             anne = getUtility(IUserManager).create_address('anne@example.com')
             anne.verified_on = verified_on
-        response, content = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com/verify', {})
-        self.assertEqual(content['status'], '204')
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(anne.verified_on, verified_on)
 
     def test_unverify_already_unverified(self):
@@ -95,9 +95,9 @@ class TestAddresses(unittest.TestCase):
         with transaction():
             anne = getUtility(IUserManager).create_address('anne@example.com')
             self.assertEqual(anne.verified_on, None)
-        response, content = call_api(
+        json, response = call_api(
            'http://localhost:9001/3.0/addresses/anne@example.com/unverify', {})
-        self.assertEqual(content['status'], '204')
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(anne.verified_on, None)
 
     def test_verify_bad_request(self):
@@ -125,15 +125,15 @@ class TestAddresses(unittest.TestCase):
         user_manager = getUtility(IUserManager)
         with transaction():
             anne = user_manager.create_user('anne@example.com')
-        response, content = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com/addresses', {
                 'email': 'anne.person@example.org',
                 })
         self.assertIn('anne.person@example.org',
                       [addr.email for addr in anne.addresses])
-        self.assertEqual(content['status'], '201')
+        self.assertEqual(response.status_code, 201)
         self.assertEqual(
-            content['location'],
+            response.headers['location'],
             'http://localhost:9001/3.0/addresses/anne.person@example.org')
         # The address has no display name.
         anne_person = user_manager.get_address('anne.person@example.org')
@@ -144,16 +144,16 @@ class TestAddresses(unittest.TestCase):
         user_manager = getUtility(IUserManager)
         with transaction():
             anne = user_manager.create_user('anne@example.com')
-        response, content = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com/addresses', {
                 'email': 'anne.person@example.org',
                 'display_name': 'Ann E Person',
                 })
         self.assertIn('anne.person@example.org',
                       [addr.email for addr in anne.addresses])
-        self.assertEqual(content['status'], '201')
+        self.assertEqual(response.status_code, 201)
         self.assertEqual(
-            content['location'],
+            response.headers['location'],
             'http://localhost:9001/3.0/addresses/anne.person@example.org')
         # The address has no display name.
         anne_person = user_manager.get_address('anne.person@example.org')
@@ -169,22 +169,22 @@ class TestAddresses(unittest.TestCase):
                      'email': 'anne@example.com',
                      })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Address belongs to other user')
+        self.assertEqual(cm.exception.reason, 'Address belongs to other user')
 
     def test_add_unlinked_address_to_user(self):
         user_manager = getUtility(IUserManager)
         with transaction():
             anne = user_manager.create_user('anne.person@example.com')
             user_manager.create_address('anne@example.com')
-        response, content = call_api(
+        json, response = call_api(
          'http://localhost:9001/3.0/users/anne.person@example.com/addresses', {
             'email': 'anne@example.com',
             })
         self.assertIn('anne@example.com',
                       [address.email for address in anne.addresses])
-        self.assertEqual(content['status'], '201')
+        self.assertEqual(response.status_code, 201)
         self.assertEqual(
-            content['location'],
+            response.headers['location'],
             'http://localhost:9001/3.0/addresses/anne@example.com')
         # The address has no display name.
         anne_person = user_manager.get_address('anne@example.com')
@@ -195,16 +195,16 @@ class TestAddresses(unittest.TestCase):
         with transaction():
             anne = user_manager.create_user('anne.person@example.com')
             user_manager.create_address('anne@example.com')
-        response, content = call_api(
+        json, response = call_api(
          'http://localhost:9001/3.0/users/anne.person@example.com/addresses', {
             'email': 'anne@example.com',
             'display_name': 'Anne Person',
             })
         self.assertIn('anne@example.com',
                       [address.email for address in anne.addresses])
-        self.assertEqual(content['status'], '201')
+        self.assertEqual(response.status_code, 201)
         self.assertEqual(
-            content['location'],
+            response.headers['location'],
             'http://localhost:9001/3.0/addresses/anne@example.com')
         # Even though a display_name was given in the POST data, because the
         # address already existed, it still has no display name.
@@ -218,16 +218,16 @@ class TestAddresses(unittest.TestCase):
         with transaction():
             anne = user_manager.create_user('anne@example.com')
             user_manager.create_user('bart@example.com')
-        response, content = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com/addresses', {
                  'email': 'bart@example.com',
                  'absorb_existing': True,
                  })
         self.assertIn('bart@example.com',
                       [address.email for address in anne.addresses])
-        self.assertEqual(content['status'], '201')
+        self.assertEqual(response.status_code, 201)
         self.assertEqual(
-            content['location'],
+            response.headers['location'],
             'http://localhost:9001/3.0/addresses/bart@example.com')
 
     def test_invalid_address_bad_request(self):
@@ -240,7 +240,7 @@ class TestAddresses(unittest.TestCase):
                      'email': 'invalid_address_string'
                      })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Invalid email address')
+        self.assertEqual(cm.exception.reason, 'Invalid email address')
 
     def test_empty_address_bad_request(self):
         # The address is required.
@@ -251,7 +251,7 @@ class TestAddresses(unittest.TestCase):
                 'http://localhost:9001/3.0/users/anne@example.com/addresses',
                 {})
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Missing parameters: email')
+        self.assertEqual(cm.exception.reason, 'Missing parameters: email')
 
     def test_get_addresses_of_missing_user(self):
         # There is no user associated with the given address.
@@ -274,9 +274,9 @@ class TestAddresses(unittest.TestCase):
         # JSON representation.
         with transaction():
             getUtility(IUserManager).create_user('anne@example.com')
-        json, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com')
-        self.assertEqual(headers['status'], '200')
+        self.assertEqual(response.status_code, 200)
         self.assertEqual(json['user'], 'http://localhost:9001/3.0/users/1')
 
     def test_address_without_user(self):
@@ -284,9 +284,9 @@ class TestAddresses(unittest.TestCase):
         # with no linked user.
         with transaction():
             getUtility(IUserManager).create_address('anne@example.com')
-        json, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com')
-        self.assertEqual(headers['status'], '200')
+        self.assertEqual(response.status_code, 200)
         self.assertNotIn('user', json)
 
     def test_user_subresource_on_unlinked_address(self):
@@ -305,15 +305,15 @@ class TestAddresses(unittest.TestCase):
         user_manager = getUtility(IUserManager)
         with transaction():
             user_manager.create_user('anne@example.com', 'Anne')
-        json, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com/user')
-        self.assertEqual(headers['status'], '200')
+        self.assertEqual(response.status_code, 200)
         self.assertEqual(json['user_id'], 1)
         self.assertEqual(json['display_name'], 'Anne')
         user_resource = json['self_link']
         self.assertEqual(user_resource, 'http://localhost:9001/3.0/users/1')
         # The self_link points to the correct user.
-        json, headers = call_api(user_resource)
+        json, response = call_api(user_resource)
         self.assertEqual(json['user_id'], 1)
         self.assertEqual(json['display_name'], 'Anne')
         self.assertEqual(json['self_link'], user_resource)
@@ -325,11 +325,11 @@ class TestAddresses(unittest.TestCase):
         with transaction():
             anne = user_manager.create_user('anne.person@example.org', 'Anne')
             anne_addr = user_manager.create_address('anne@example.com')
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com/user', {
                 'user_id': anne.user_id.int,
                 })
-        self.assertEqual(headers['status'], '200')
+        self.assertEqual(response.status_code, 200)
         self.assertEqual(anne_addr.user, anne)
         self.assertEqual(sorted([a.email for a in anne.addresses]),
                          ['anne.person@example.org', 'anne@example.com'])
@@ -340,18 +340,18 @@ class TestAddresses(unittest.TestCase):
         user_manager = getUtility(IUserManager)
         with transaction():
             anne_addr = user_manager.create_address('anne@example.com')
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com/user', {
                 'display_name': 'Anne',
                 })
-        self.assertEqual(headers['status'], '201')
+        self.assertEqual(response.status_code, 201)
         anne = user_manager.get_user('anne@example.com')
         self.assertIsNotNone(anne)
         self.assertEqual(anne.display_name, 'Anne')
         self.assertEqual([a.email for a in anne.addresses],
                          ['anne@example.com'])
         self.assertEqual(anne_addr.user, anne)
-        self.assertEqual(headers['location'],
+        self.assertEqual(response.headers['location'],
                          'http://localhost:9001/3.0/users/1')
 
     def test_user_subresource_post_conflict(self):
@@ -373,7 +373,7 @@ class TestAddresses(unittest.TestCase):
         with transaction():
             getUtility(IUserManager).create_address('anne@example.com')
         with self.assertRaises(HTTPError) as cm:
-            json, headers = call_api(
+            call_api(
                 'http://localhost:9001/3.0/addresses/anne@example.com/user', {
                     'display_name': 'Anne',
                     'auto_create': 0,
@@ -390,7 +390,7 @@ class TestAddresses(unittest.TestCase):
                     'user_id': 2,
                     })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'No user with ID 2')
+        self.assertEqual(cm.exception.reason, 'No user with ID 2')
 
     def test_user_subresource_unlink(self):
         # By DELETEing the usr subresource, you can unlink a user from an
@@ -398,10 +398,10 @@ class TestAddresses(unittest.TestCase):
         user_manager = getUtility(IUserManager)
         with transaction():
             user_manager.create_user('anne@example.com')
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com/user',
             method='DELETE')
-        self.assertEqual(headers['status'], '204')
+        self.assertEqual(response.status_code, 204)
         anne_addr = user_manager.get_address('anne@example.com')
         self.assertIsNone(anne_addr.user, 'The address is still linked')
         self.assertIsNone(user_manager.get_user('anne@example.com'))
@@ -412,7 +412,7 @@ class TestAddresses(unittest.TestCase):
         with transaction():
             user_manager.create_address('anne@example.com')
         with self.assertRaises(HTTPError) as cm:
-            response, headers = call_api(
+            call_api(
                 'http://localhost:9001/3.0/addresses/anne@example.com/user',
                 method='DELETE')
         self.assertEqual(cm.exception.code, 404)
@@ -424,11 +424,11 @@ class TestAddresses(unittest.TestCase):
         with transaction():
             anne = user_manager.create_user('anne@example.com', 'Anne')
             bart = user_manager.create_user(display_name='Bart')
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com/user', {
                 'user_id': bart.user_id.int,
                 }, method='PUT')
-        self.assertEqual(headers['status'], '200')
+        self.assertEqual(response.status_code, 200)
         self.assertEqual(anne.addresses, [])
         self.assertEqual([address.email for address in bart.addresses],
                          ['anne@example.com'])
@@ -440,11 +440,11 @@ class TestAddresses(unittest.TestCase):
         user_manager = getUtility(IUserManager)
         with transaction():
             anne = user_manager.create_user('anne@example.com', 'Anne')
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/addresses/anne@example.com/user', {
                 'email': 'anne.person@example.org',
                 }, method='PUT')
-        self.assertEqual(headers['status'], '201')
+        self.assertEqual(response.status_code, 201)
         self.assertEqual(anne.addresses, [])
         anne_person = user_manager.get_user('anne.person@example.org')
         self.assertIsNotNone(anne_person)
@@ -459,7 +459,7 @@ class TestAddresses(unittest.TestCase):
         # DELETEing an address through the REST API that doesn't exist returns
         # a 404 error.
         with self.assertRaises(HTTPError) as cm:
-            response, headers = call_api(
+            call_api(
                 'http://localhost:9001/3.0/addresses/anne@example.com',
                 method='DELETE')
         self.assertEqual(cm.exception.code, 404)
@@ -512,10 +512,10 @@ class TestAPI31Addresses(unittest.TestCase):
         user_manager = getUtility(IUserManager)
         with transaction():
             user_manager.create_user('anne@example.com', 'Anne')
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/addresses/anne@example.com')
         self.assertEqual(
-            response['user'],
+            json['user'],
             'http://localhost:9001/3.1/users/00000000000000000000000000000001')
 
     def test_addresses_user_ids_are_hex(self):
@@ -525,8 +525,8 @@ class TestAPI31Addresses(unittest.TestCase):
             user_manager.create_user('anne@example.com', 'Anne')
         with transaction():
             user_manager.create_user('bart@example.com', 'Bart')
-        response, headers = call_api('http://localhost:9001/3.1/addresses')
-        entries = response['entries']
+        json, response = call_api('http://localhost:9001/3.1/addresses')
+        entries = json['entries']
         self.assertEqual(
             entries[0]['user'],
             'http://localhost:9001/3.1/users/00000000000000000000000000000001')
@@ -542,11 +542,11 @@ class TestAPI31Addresses(unittest.TestCase):
         with transaction():
             anne = user_manager.create_user('anne.person@example.org', 'Anne')
             anne_addr = user_manager.create_address('anne@example.com')
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/addresses/anne@example.com/user', {
                 'user_id': anne.user_id.hex,
                 })
-        self.assertEqual(headers['status'], '200')
+        self.assertEqual(response.status_code, 200)
         self.assertEqual(anne_addr.user, anne)
         self.assertEqual(sorted([a.email for a in anne.addresses]),
                          ['anne.person@example.org', 'anne@example.com'])
@@ -566,7 +566,7 @@ class TestAPI31Addresses(unittest.TestCase):
                     })
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Cannot convert parameters: user_id')
+                         'Cannot convert parameters: user_id')
 
     def test_user_subresource_put(self):
         # By PUTing to the 'user' resource, you can change the user that an
@@ -575,11 +575,11 @@ class TestAPI31Addresses(unittest.TestCase):
         with transaction():
             anne = user_manager.create_user('anne@example.com', 'Anne')
             bart = user_manager.create_user(display_name='Bart')
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/addresses/anne@example.com/user', {
                 'user_id': bart.user_id.hex,
                 }, method='PUT')
-        self.assertEqual(headers['status'], '200')
+        self.assertEqual(response.status_code, 200)
         self.assertEqual(anne.addresses, [])
         self.assertEqual([address.email for address in bart.addresses],
                          ['anne@example.com'])
@@ -601,4 +601,4 @@ class TestAPI31Addresses(unittest.TestCase):
                     }, method='PUT')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Cannot convert parameters: user_id')
+                         'Cannot convert parameters: user_id')
diff --git a/src/mailman/rest/tests/test_bans.py b/src/mailman/rest/tests/test_bans.py
index 877f6692c..8866bd80b 100644
--- a/src/mailman/rest/tests/test_bans.py
+++ b/src/mailman/rest/tests/test_bans.py
@@ -40,7 +40,7 @@ class TestBans(unittest.TestCase):
                      '/bans/notbanned@example.com')
         self.assertEqual(cm.exception.code, 404)
         self.assertEqual(cm.exception.reason,
-                         b'Email is not banned: notbanned@example.com')
+                         'Email is not banned: notbanned@example.com')
 
     def test_delete_missing_banned_address(self):
         with self.assertRaises(HTTPError) as cm:
@@ -49,7 +49,7 @@ class TestBans(unittest.TestCase):
                      method='DELETE')
         self.assertEqual(cm.exception.code, 404)
         self.assertEqual(cm.exception.reason,
-                         b'Email is not banned: notbanned@example.com')
+                         'Email is not banned: notbanned@example.com')
 
     def test_not_found_after_unbanning(self):
         manager = IBanManager(self._mlist)
@@ -57,30 +57,30 @@ class TestBans(unittest.TestCase):
             manager.ban('banned@example.com')
         url = ('http://localhost:9001/3.0/lists/ant.example.com'
                '/bans/banned@example.com')
-        response, content = call_api(url)
-        self.assertEqual(response['email'], 'banned@example.com')
-        response, content = call_api(url, method='DELETE')
-        self.assertEqual(content.status, 204)
+        json, response = call_api(url)
+        self.assertEqual(json['email'], 'banned@example.com')
+        json, response = call_api(url, method='DELETE')
+        self.assertEqual(response.status_code, 204)
         with self.assertRaises(HTTPError) as cm:
             call_api(url)
         self.assertEqual(cm.exception.code, 404)
         self.assertEqual(cm.exception.reason,
-                         b'Email is not banned: banned@example.com')
+                         'Email is not banned: banned@example.com')
 
     def test_not_found_after_unbanning_global(self):
         manager = IBanManager(None)
         with transaction():
             manager.ban('banned@example.com')
         url = ('http://localhost:9001/3.0/bans/banned@example.com')
-        response, content = call_api(url)
-        self.assertEqual(response['email'], 'banned@example.com')
-        response, content = call_api(url, method='DELETE')
-        self.assertEqual(content.status, 204)
+        json, response = call_api(url)
+        self.assertEqual(json['email'], 'banned@example.com')
+        json, response = call_api(url, method='DELETE')
+        self.assertEqual(response.status_code, 204)
         with self.assertRaises(HTTPError) as cm:
             call_api(url)
         self.assertEqual(cm.exception.code, 404)
         self.assertEqual(cm.exception.reason,
-                         b'Email is not banned: banned@example.com')
+                         'Email is not banned: banned@example.com')
 
     def test_ban_missing_mailing_list(self):
         with self.assertRaises(HTTPError) as cm:
diff --git a/src/mailman/rest/tests/test_basic.py b/src/mailman/rest/tests/test_basic.py
index 2799c6f83..16ec2f5a3 100644
--- a/src/mailman/rest/tests/test_basic.py
+++ b/src/mailman/rest/tests/test_basic.py
@@ -27,6 +27,7 @@ from mailman.database.transaction import transaction
 from mailman.testing.helpers import call_api
 from mailman.testing.layers import RESTLayer
 from urllib.error import HTTPError
+from urllib.request import urlopen
 
 
 class TestBasicREST(unittest.TestCase):
@@ -39,7 +40,7 @@ class TestBasicREST(unittest.TestCase):
             self._mlist = create_list('test@example.com')
 
     def test_comma_fields(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/test@example.com/config',
             dict(description='A description with , to check stuff'),
             method='PATCH')
@@ -50,6 +51,8 @@ class TestBasicREST(unittest.TestCase):
     def test_send_error(self):
         # GL#288 working around Python bug #28548.  The improperly encoded
         # space in the URL breaks error reporting due to default HTTP/0.9.
+        # Use urllib.request since requests will encode the URL, defeating the
+        # purpose of this test (i.e. we want the literal space, not %20).
         with self.assertRaises(HTTPError) as cm:
-            call_api('http://localhost:9001/3.0/lists/test @example.com')
+            urlopen('http://localhost:9001/3.0/lists/test @example.com')
         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 bbbd54ef3..3bacf7a72 100644
--- a/src/mailman/rest/tests/test_domains.py
+++ b/src/mailman/rest/tests/test_domains.py
@@ -46,7 +46,7 @@ class TestDomains(unittest.TestCase):
             )
         content, response = call_api(
             'http://localhost:9001/3.0/domains', data, method="POST")
-        self.assertEqual(response.status, 201)
+        self.assertEqual(response.status_code, 201)
 
     def test_patch_domain_description(self):
         # Patch the example.com description.
@@ -55,7 +55,7 @@ class TestDomains(unittest.TestCase):
             'http://localhost:9001/3.0/domains/example.com',
             data,
             method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Check the result.
         domain = getUtility(IDomainManager).get('example.com')
         self.assertEqual(domain.description, 'Patched example domain')
@@ -67,7 +67,7 @@ class TestDomains(unittest.TestCase):
             'http://localhost:9001/3.0/domains/example.com',
             data,
             method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Check the result.
         domain = getUtility(IDomainManager).get('example.com')
         self.assertEqual(
@@ -81,7 +81,7 @@ class TestDomains(unittest.TestCase):
             'http://localhost:9001/3.0/domains/example.com',
             data,
             method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Check the result.
         domain = getUtility(IDomainManager).get('example.com')
         self.assertEqual(
@@ -106,7 +106,7 @@ class TestDomains(unittest.TestCase):
                 owner='anne@example.com',
                 ),
             method='POST')
-        self.assertEqual(response.status, 201)
+        self.assertEqual(response.status_code, 201)
         # The domain has the expected owner.
         domain = getUtility(IDomainManager).get('example.net')
         self.assertEqual(
@@ -132,7 +132,7 @@ class TestDomains(unittest.TestCase):
             create_list('ant@example.com')
         content, response = call_api(
             'http://localhost:9001/3.0/domains/example.com', method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertIsNone(getUtility(IListManager).get('ant@example.com'))
 
     def test_missing_domain(self):
@@ -161,7 +161,7 @@ class TestDomains(unittest.TestCase):
         content, response = call_api(
             'http://localhost:9001/3.0/domains/example.com',
             method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/domains/example.com',
                      method='DELETE')
@@ -255,7 +255,7 @@ class TestDomainTemplates(unittest.TestCase):
                 )
         resource, response = call_api(
             'http://localhost:9001/3.1/domains/example.com/uris')
-        self.assertEqual(response.status, 200)
+        self.assertEqual(response.status_code, 200)
         self.assertEqual(resource['start'], 0)
         self.assertEqual(resource['total_size'], 2)
         self.assertEqual(
@@ -283,7 +283,7 @@ class TestDomainTemplates(unittest.TestCase):
                 'list:user:notice:welcome': 'http://example.org/welcome',
                 'list:user:notice:goodbye': 'http://example.org/goodbye',
                 }, method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         manager = getUtility(ITemplateManager)
         template = manager.raw('list:user:notice:welcome', 'example.com')
         self.assertEqual(template.uri, 'http://example.org/welcome')
@@ -302,7 +302,7 @@ class TestDomainTemplates(unittest.TestCase):
                 'password': 'some password',
                 'username': 'anne.person',
                 }, method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         manager = getUtility(ITemplateManager)
         template = manager.raw('list:user:notice:welcome', 'example.com')
         self.assertEqual(template.uri, 'http://example.org/welcome')
@@ -350,7 +350,7 @@ class TestDomainTemplates(unittest.TestCase):
                 'password': 'some password',
                 'username': 'anne.person',
                 }, method='PUT')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         manager = getUtility(ITemplateManager)
         template = manager.raw('list:member:digest:footer', 'example.com')
         self.assertIsNone(template)
@@ -387,7 +387,7 @@ class TestDomainTemplates(unittest.TestCase):
         resource, response = call_api(
             'http://localhost:9001/3.1/domains/example.com/uris',
             method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertIsNone(
             manager.raw('list:user:notice:welcome', 'example.com'))
         self.assertIsNone(
@@ -401,7 +401,7 @@ class TestDomainTemplates(unittest.TestCase):
         resource, response = call_api(
             'http://localhost:9001/3.1/domains/example.com/uris'
             '/list:user:notice:welcome')
-        self.assertEqual(response.status, 200)
+        self.assertEqual(response.status_code, 200)
         self.assertEqual(resource, {
             'http_etag': '"8884a0b3d675b4cb9899a7825daac9db88b70bed"',
             'self_link': ('http://localhost:9001/3.1/domains/example.com'
diff --git a/src/mailman/rest/tests/test_header_matches.py b/src/mailman/rest/tests/test_header_matches.py
index 892d258b0..a02b15f2e 100644
--- a/src/mailman/rest/tests/test_header_matches.py
+++ b/src/mailman/rest/tests/test_header_matches.py
@@ -40,7 +40,7 @@ class TestHeaderMatches(unittest.TestCase):
                      '/header-matches/0')
         self.assertEqual(cm.exception.code, 404)
         self.assertEqual(cm.exception.reason,
-                         b'No header match at this position: 0')
+                         'No header match at this position: 0')
 
     def test_delete_missing_header_match(self):
         with self.assertRaises(HTTPError) as cm:
@@ -49,7 +49,7 @@ class TestHeaderMatches(unittest.TestCase):
                      method='DELETE')
         self.assertEqual(cm.exception.code, 404)
         self.assertEqual(cm.exception.reason,
-                         b'No header match at this position: 0')
+                         'No header match at this position: 0')
 
     def test_add_duplicate(self):
         header_matches = IHeaderMatchList(self._mlist)
@@ -63,7 +63,7 @@ class TestHeaderMatches(unittest.TestCase):
                         })
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'This header match already exists')
+                         'This header match already exists')
 
     def test_header_match_on_missing_list(self):
         with self.assertRaises(HTTPError) as cm:
diff --git a/src/mailman/rest/tests/test_listconf.py b/src/mailman/rest/tests/test_listconf.py
index c5dc93ff9..06c138fee 100644
--- a/src/mailman/rest/tests/test_listconf.py
+++ b/src/mailman/rest/tests/test_listconf.py
@@ -96,35 +96,35 @@ class TestConfiguration(unittest.TestCase):
             call_api(
                 'http://localhost:9001/3.0/lists/ant.example.com/config/bogus')
         self.assertEqual(cm.exception.code, 404)
-        self.assertEqual(cm.exception.reason, b'Unknown attribute: bogus')
+        self.assertEqual(cm.exception.reason, 'Unknown attribute: bogus')
 
     def test_put_configuration(self):
         # When using PUT, all writable attributes must be included.
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant.example.com/config',
             RESOURCE,
             'PUT')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(self._mlist.display_name, 'Fnords')
         # All three acceptable aliases were set.
         self.assertEqual(set(IAcceptableAliasSet(self._mlist).aliases),
                          set(RESOURCE['acceptable_aliases']))
 
     def test_put_attribute(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant.example.com'
             '/config/reply_to_address')
-        self.assertEqual(resource['reply_to_address'], '')
-        resource, response = call_api(
+        self.assertEqual(json['reply_to_address'], '')
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant.example.com'
             '/config/reply_to_address',
             dict(reply_to_address='bar@ant.example.com'),
             'PUT')
-        self.assertEqual(response.status, 204)
-        resource, response = call_api(
+        self.assertEqual(response.status_code, 204)
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant.example.com'
             '/config/reply_to_address')
-        self.assertEqual(resource['reply_to_address'], 'bar@ant.example.com')
+        self.assertEqual(json['reply_to_address'], 'bar@ant.example.com')
 
     def test_put_extra_attribute(self):
         bogus_resource = RESOURCE.copy()
@@ -135,22 +135,22 @@ class TestConfiguration(unittest.TestCase):
                 bogus_resource,
                 'PUT')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Unexpected parameters: bogus')
+        self.assertEqual(cm.exception.reason, 'Unexpected parameters: bogus')
 
     def test_put_attribute_mismatch(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant.example.com'
             '/config/reply_to_address')
-        self.assertEqual(resource['reply_to_address'], '')
+        self.assertEqual(json['reply_to_address'], '')
         with self.assertRaises(HTTPError) as cm:
-            resource, response = call_api(
+            json, response = call_api(
                 'http://localhost:9001/3.0/lists/ant.example.com'
                 '/config/reply_to_address',
                 dict(display_name='bar@ant.example.com'),
                 'PUT')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Unexpected parameters: display_name')
+                         'Unexpected parameters: display_name')
 
     def test_put_attribute_double(self):
         with self.assertRaises(HTTPError) as cm:
@@ -162,7 +162,7 @@ class TestConfiguration(unittest.TestCase):
                 'PUT')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Unexpected parameters: display_name')
+                         'Unexpected parameters: display_name')
 
     def test_put_read_only_attribute(self):
         with self.assertRaises(HTTPError) as cm:
@@ -171,8 +171,7 @@ class TestConfiguration(unittest.TestCase):
                      dict(mail_host='foo.example.com'),
                      'PUT')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason,
-                         b'Read-only attribute: mail_host')
+        self.assertEqual(cm.exception.reason, 'Read-only attribute: mail_host')
 
     def test_put_missing_attribute(self):
         with self.assertRaises(HTTPError) as cm:
@@ -181,7 +180,7 @@ class TestConfiguration(unittest.TestCase):
                 dict(bogus='no matter'),
                 'PUT')
         self.assertEqual(cm.exception.code, 404)
-        self.assertEqual(cm.exception.reason, b'Unknown attribute: bogus')
+        self.assertEqual(cm.exception.reason, 'Unknown attribute: bogus')
 
     def test_patch_subscription_policy(self):
         # The new subscription_policy value can be patched.
@@ -195,7 +194,7 @@ class TestConfiguration(unittest.TestCase):
             'http://localhost:9001/3.0/lists/ant.example.com/config', dict(
                 subscription_policy='confirm_then_moderate'),
             method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # And now we verify that it has the requested setting.
         self.assertEqual(self._mlist.subscription_policy,
                          SubscriptionPolicy.confirm_then_moderate)
@@ -209,7 +208,7 @@ class TestConfiguration(unittest.TestCase):
                      reply_to_address='foo'),
                 'PATCH')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Expected 1 attribute, got 2')
+        self.assertEqual(cm.exception.reason, 'Expected 1 attribute, got 2')
 
     def test_unknown_patch_attribute(self):
         with self.assertRaises(HTTPError) as cm:
@@ -217,7 +216,7 @@ class TestConfiguration(unittest.TestCase):
                      dict(bogus=1),
                      'PATCH')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Unknown attribute: bogus')
+        self.assertEqual(cm.exception.reason, 'Unknown attribute: bogus')
 
     def test_read_only_patch_attribute(self):
         with self.assertRaises(HTTPError) as cm:
@@ -226,8 +225,7 @@ class TestConfiguration(unittest.TestCase):
                      dict(mail_host='foo.example.com'),
                      'PATCH')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason,
-                         b'Read-only attribute: mail_host')
+        self.assertEqual(cm.exception.reason, 'Read-only attribute: mail_host')
 
     def test_patch_missing_attribute(self):
         with self.assertRaises(HTTPError) as cm:
@@ -236,7 +234,7 @@ class TestConfiguration(unittest.TestCase):
                 dict(bogus='no matter'),
                 'PATCH')
         self.assertEqual(cm.exception.code, 404)
-        self.assertEqual(cm.exception.reason, b'Unknown attribute: bogus')
+        self.assertEqual(cm.exception.reason, 'Unknown attribute: bogus')
 
     def test_patch_bad_value(self):
         with self.assertRaises(HTTPError) as cm:
@@ -247,7 +245,7 @@ class TestConfiguration(unittest.TestCase):
                 'PATCH')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Cannot convert parameters: archive_policy')
+                         'Cannot convert parameters: archive_policy')
 
     def test_bad_pipeline_name(self):
         with self.assertRaises(HTTPError) as cm:
@@ -258,7 +256,7 @@ class TestConfiguration(unittest.TestCase):
                 'PATCH')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Cannot convert parameters: posting_pipeline')
+                         'Cannot convert parameters: posting_pipeline')
 
     def test_get_digest_send_periodic(self):
         with transaction():
@@ -276,7 +274,7 @@ class TestConfiguration(unittest.TestCase):
             '/digest_send_periodic',
             dict(digest_send_periodic=True),
             'PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertTrue(self._mlist.digest_send_periodic)
 
     def test_put_digest_send_periodic(self):
@@ -287,7 +285,7 @@ class TestConfiguration(unittest.TestCase):
             '/digest_send_periodic',
             dict(digest_send_periodic=True),
             'PUT')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertTrue(self._mlist.digest_send_periodic)
 
     def test_get_digest_volume_frequency(self):
@@ -306,7 +304,7 @@ class TestConfiguration(unittest.TestCase):
             '/digest_volume_frequency',
             dict(digest_volume_frequency='monthly'),
             'PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(self._mlist.digest_volume_frequency,
                          DigestFrequency.monthly)
 
@@ -318,7 +316,7 @@ class TestConfiguration(unittest.TestCase):
             '/digest_volume_frequency',
             dict(digest_volume_frequency='monthly'),
             'PUT')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(self._mlist.digest_volume_frequency,
                          DigestFrequency.monthly)
 
@@ -333,7 +331,7 @@ class TestConfiguration(unittest.TestCase):
                 'PATCH')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Cannot convert parameters: digest_volume_frequency')
+                         'Cannot convert parameters: digest_volume_frequency')
 
     def test_bad_put_digest_volume_frequency(self):
         with transaction():
@@ -346,7 +344,7 @@ class TestConfiguration(unittest.TestCase):
                 'PUT')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Cannot convert parameters: digest_volume_frequency')
+                         'Cannot convert parameters: digest_volume_frequency')
 
     def test_get_digests_enabled(self):
         with transaction():
@@ -364,7 +362,7 @@ class TestConfiguration(unittest.TestCase):
             '/digests_enabled',
             dict(digests_enabled=True),
             'PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertTrue(self._mlist.digests_enabled)
 
     def test_put_digests_enabled(self):
@@ -375,7 +373,7 @@ class TestConfiguration(unittest.TestCase):
             '/digests_enabled',
             dict(digests_enabled=True),
             'PUT')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertTrue(self._mlist.digests_enabled)
 
     def test_get_goodbye_message_uri(self):
@@ -394,7 +392,7 @@ class TestConfiguration(unittest.TestCase):
             'http://localhost:9001/3.0/lists/ant.example.com/config',
             dict(goodbye_message_uri='mailman:///salutation.txt'),
             'PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(
             getUtility(ITemplateManager).raw(
                 'user:ack:goodbye', self._mlist.list_id).uri,
@@ -406,7 +404,7 @@ class TestConfiguration(unittest.TestCase):
             '/goodbye_message_uri',
             dict(goodbye_message_uri='mailman:///salutation.txt'),
             'PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(
             getUtility(ITemplateManager).raw(
                 'user:ack:goodbye', self._mlist.list_id).uri,
@@ -424,7 +422,7 @@ class TestConfiguration(unittest.TestCase):
             '/goodbye_message_uri',
             dict(goodbye_message_uri='mailman:///salutation.txt'),
             'PUT')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(
             manager.raw('user:ack:goodbye', self._mlist.list_id).uri,
             'mailman:///salutation.txt')
@@ -453,7 +451,7 @@ class TestConfiguration(unittest.TestCase):
                 'PATCH')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Cannot convert parameters: description')
+                         'Cannot convert parameters: description')
 
     def test_patch_info(self):
         with transaction():
diff --git a/src/mailman/rest/tests/test_lists.py b/src/mailman/rest/tests/test_lists.py
index 2481bedcd..7bb7bd333 100644
--- a/src/mailman/rest/tests/test_lists.py
+++ b/src/mailman/rest/tests/test_lists.py
@@ -86,20 +86,20 @@ class TestLists(unittest.TestCase):
 
     def test_member_count_with_no_members(self):
         # The list initially has 0 members.
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/test@example.com')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(resource['member_count'], 0)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json['member_count'], 0)
 
     def test_member_count_with_one_member(self):
         # Add a member to a list and check that the resource reflects this.
         with transaction():
             anne = self._usermanager.create_address('anne@example.com')
             self._mlist.subscribe(anne)
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/test@example.com')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(resource['member_count'], 1)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json['member_count'], 1)
 
     def test_member_count_with_two_members(self):
         # Add two members to a list and check that the resource reflects this.
@@ -108,10 +108,10 @@ class TestLists(unittest.TestCase):
             self._mlist.subscribe(anne)
             bart = self._usermanager.create_address('bar@example.com')
             self._mlist.subscribe(bart)
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/test@example.com')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(resource['member_count'], 2)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json['member_count'], 2)
 
     def test_query_for_lists_in_missing_domain(self):
         # You cannot ask all the mailing lists in a non-existent domain.
@@ -127,7 +127,7 @@ class TestLists(unittest.TestCase):
                      })
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Domain does not exist: no-domain.example.org')
+                         'Domain does not exist: no-domain.example.org')
 
     def test_cannot_create_duplicate_list(self):
         # You cannot create a list that already exists.
@@ -139,7 +139,7 @@ class TestLists(unittest.TestCase):
                      'fqdn_listname': 'ant@example.com',
                      })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Mailing list exists')
+        self.assertEqual(cm.exception.reason, 'Mailing list exists')
 
     def test_cannot_delete_missing_list(self):
         # You cannot delete a list that does not exist.
@@ -167,14 +167,14 @@ class TestLists(unittest.TestCase):
             bart = self._usermanager.create_address('bart@example.com')
             self._mlist.subscribe(anne)
             self._mlist.subscribe(bart)
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/test@example.com/roster/member')
-        self.assertEqual(resource['start'], 0)
-        self.assertEqual(resource['total_size'], 2)
-        member = resource['entries'][0]
+        self.assertEqual(json['start'], 0)
+        self.assertEqual(json['total_size'], 2)
+        member = json['entries'][0]
         self.assertEqual(member['email'], 'anne@example.com')
         self.assertEqual(member['role'], 'member')
-        member = resource['entries'][1]
+        member = json['entries'][1]
         self.assertEqual(member['email'], 'bart@example.com')
         self.assertEqual(member['role'], 'member')
 
@@ -222,19 +222,20 @@ class TestLists(unittest.TestCase):
             self._mlist.subscribe(aperson)
             self._mlist.subscribe(bperson)
             self._mlist.subscribe(cperson)
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/test.example.com'
             '/roster/member', {
                 'emails': ['aperson@example.com',
                            'bperson@example.com',
                            ]},
             'DELETE')
-        self.assertEqual(response.status, 200)
+        self.assertEqual(response.status_code, 200)
         # Remove variable data.
-        resource.pop('http_etag')
-        self.assertEqual(resource, {'aperson@example.com': True,
-                                    'bperson@example.com': True,
-                                    })
+        json.pop('http_etag')
+        self.assertEqual(json, {
+            'aperson@example.com': True,
+            'bperson@example.com': True,
+            })
 
     def test_list_mass_unsubscribe_all_fail(self):
         with transaction():
@@ -244,19 +245,20 @@ class TestLists(unittest.TestCase):
             self._mlist.subscribe(aperson)
             self._mlist.subscribe(bperson)
             self._mlist.subscribe(cperson)
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/test.example.com'
             '/roster/member', {
                 'emails': ['yperson@example.com',
                            'zperson@example.com',
                            ]},
             'DELETE')
-        self.assertEqual(response.status, 200)
+        self.assertEqual(response.status_code, 200)
         # Remove variable data.
-        resource.pop('http_etag')
-        self.assertEqual(resource, {'yperson@example.com': False,
-                                    'zperson@example.com': False,
-                                    })
+        json.pop('http_etag')
+        self.assertEqual(json, {
+            'yperson@example.com': False,
+            'zperson@example.com': False,
+            })
 
     def test_list_mass_unsubscribe_mixed_success(self):
         with transaction():
@@ -266,19 +268,20 @@ class TestLists(unittest.TestCase):
             self._mlist.subscribe(aperson)
             self._mlist.subscribe(bperson)
             self._mlist.subscribe(cperson)
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/test.example.com'
             '/roster/member', {
                 'emails': ['aperson@example.com',
                            'zperson@example.com',
                            ]},
             'DELETE')
-        self.assertEqual(response.status, 200)
+        self.assertEqual(response.status_code, 200)
         # Remove variable data.
-        resource.pop('http_etag')
-        self.assertEqual(resource, {'aperson@example.com': True,
-                                    'zperson@example.com': False,
-                                    })
+        json.pop('http_etag')
+        self.assertEqual(json, {
+            'aperson@example.com': True,
+            'zperson@example.com': False,
+            })
 
     def test_list_mass_unsubscribe_with_duplicates(self):
         with transaction():
@@ -288,7 +291,7 @@ class TestLists(unittest.TestCase):
             self._mlist.subscribe(aperson)
             self._mlist.subscribe(bperson)
             self._mlist.subscribe(cperson)
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/test.example.com'
             '/roster/member', {
                 'emails': ['aperson@example.com',
@@ -297,13 +300,14 @@ class TestLists(unittest.TestCase):
                            'zperson@example.com',
                            ]},
             'DELETE')
-        self.assertEqual(response.status, 200)
+        self.assertEqual(response.status_code, 200)
         # Remove variable data.
-        resource.pop('http_etag')
-        self.assertEqual(resource, {'aperson@example.com': True,
-                                    'bperson@example.com': True,
-                                    'zperson@example.com': False,
-                                    })
+        json.pop('http_etag')
+        self.assertEqual(json, {
+            'aperson@example.com': True,
+            'bperson@example.com': True,
+            'zperson@example.com': False,
+            })
 
     def test_list_mass_unsubscribe_bogus_list(self):
         with self.assertRaises(HTTPError) as cm:
@@ -318,7 +322,7 @@ class TestLists(unittest.TestCase):
                      '/roster/member',
                      None, 'DELETE')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Missing parameters: emails')
+        self.assertEqual(cm.exception.reason, 'Missing parameters: emails')
 
 
 class TestListArchivers(unittest.TestCase):
@@ -331,12 +335,12 @@ class TestListArchivers(unittest.TestCase):
             self._mlist = create_list('ant@example.com')
 
     def test_archiver_statuses(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant.example.com/archivers')
-        self.assertEqual(response.status, 200)
+        self.assertEqual(response.status_code, 200)
         # Remove the variable data.
-        resource.pop('http_etag')
-        self.assertEqual(resource, {
+        json.pop('http_etag')
+        self.assertEqual(json, {
             'mail-archive': True,
             'mhonarc': True,
             })
@@ -358,7 +362,7 @@ class TestListArchivers(unittest.TestCase):
                 method='PUT')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Unexpected parameters: bogus-archiver')
+                         'Unexpected parameters: bogus-archiver')
 
     def test_patch_bogus_archiver(self):
         # You cannot PATCH on an archiver the list doesn't know about.
@@ -370,7 +374,7 @@ class TestListArchivers(unittest.TestCase):
                 method='PATCH')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Unexpected parameters: bogus-archiver')
+                         'Unexpected parameters: bogus-archiver')
 
     def test_put_incomplete_statuses(self):
         # PUT requires the full resource representation.  This one forgets to
@@ -382,8 +386,7 @@ class TestListArchivers(unittest.TestCase):
                     },
                 method='PUT')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason,
-                         b'Missing parameters: mhonarc')
+        self.assertEqual(cm.exception.reason, 'Missing parameters: mhonarc')
 
     def test_patch_bogus_status(self):
         # Archiver statuses must be interpretable as booleans.
@@ -395,7 +398,7 @@ class TestListArchivers(unittest.TestCase):
                     },
                 method='PATCH')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Invalid boolean value: sure')
+        self.assertEqual(cm.exception.reason, 'Invalid boolean value: sure')
 
 
 class TestListPagination(unittest.TestCase):
@@ -419,36 +422,36 @@ class TestListPagination(unittest.TestCase):
             create_list('fly@example.com')
 
     def test_first_page(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/domains/example.com/lists'
             '?count=1&page=1')
         # There are 6 total lists, but only the first one in the page.
-        self.assertEqual(resource['total_size'], 6)
-        self.assertEqual(resource['start'], 0)
-        self.assertEqual(len(resource['entries']), 1)
-        entry = resource['entries'][0]
+        self.assertEqual(json['total_size'], 6)
+        self.assertEqual(json['start'], 0)
+        self.assertEqual(len(json['entries']), 1)
+        entry = json['entries'][0]
         self.assertEqual(entry['fqdn_listname'], 'ant@example.com')
 
     def test_second_page(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/domains/example.com/lists'
             '?count=1&page=2')
         # There are 6 total lists, but only the first one in the page.
-        self.assertEqual(resource['total_size'], 6)
-        self.assertEqual(resource['start'], 1)
-        self.assertEqual(len(resource['entries']), 1)
-        entry = resource['entries'][0]
+        self.assertEqual(json['total_size'], 6)
+        self.assertEqual(json['start'], 1)
+        self.assertEqual(len(json['entries']), 1)
+        entry = json['entries'][0]
         self.assertEqual(entry['fqdn_listname'], 'bee@example.com')
 
     def test_last_page(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/domains/example.com/lists'
             '?count=1&page=6')
         # There are 6 total lists, but only the first one in the page.
-        self.assertEqual(resource['total_size'], 6)
-        self.assertEqual(resource['start'], 5)
-        self.assertEqual(len(resource['entries']), 1)
-        entry = resource['entries'][0]
+        self.assertEqual(json['total_size'], 6)
+        self.assertEqual(json['start'], 5)
+        self.assertEqual(len(json['entries']), 1)
+        entry = json['entries'][0]
         self.assertEqual(entry['fqdn_listname'], 'fly@example.com')
 
     def test_zeroth_page(self):
@@ -469,13 +472,13 @@ class TestListPagination(unittest.TestCase):
 
     def test_past_last_page(self):
         # The 7th page doesn't exist so the collection is empty.
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/domains/example.com/lists'
             '?count=1&page=7')
         # There are 6 total lists, but only the first one in the page.
-        self.assertEqual(resource['total_size'], 6)
-        self.assertEqual(resource['start'], 6)
-        self.assertNotIn('entries', resource)
+        self.assertEqual(json['total_size'], 6)
+        self.assertEqual(json['start'], 6)
+        self.assertNotIn('entries', json)
 
 
 class TestListDigests(unittest.TestCase):
@@ -498,15 +501,15 @@ class TestListDigests(unittest.TestCase):
         self.assertEqual(cm.exception.code, 404)
 
     def test_post_nothing_to_do(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant.example.com/digest', {})
-        self.assertEqual(response.status, 200)
+        self.assertEqual(response.status_code, 200)
 
     def test_post_something_to_do(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant.example.com/digest', dict(
                 bump=True))
-        self.assertEqual(response.status, 202)
+        self.assertEqual(response.status_code, 202)
 
     def test_post_bad_request(self):
         with self.assertRaises(HTTPError) as cm:
@@ -514,7 +517,7 @@ class TestListDigests(unittest.TestCase):
                 'http://localhost:9001/3.0/lists/ant.example.com/digest', dict(
                     bogus=True))
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Unexpected parameters: bogus')
+        self.assertEqual(cm.exception.reason, 'Unexpected parameters: bogus')
 
     def test_bump_before_send(self):
         with transaction():
@@ -530,11 +533,11 @@ Subject: message 1
 
 """)
         config.handlers['to-digest'].process(self._mlist, msg, {})
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant.example.com/digest', dict(
                 send=True,
                 bump=True))
-        self.assertEqual(response.status, 202)
+        self.assertEqual(response.status_code, 202)
         make_testable_runner(DigestRunner, 'digest').run()
         # The volume is 8 and the digest number is 2 because a digest was sent
         # after the volume/number was bumped.
@@ -588,15 +591,15 @@ class TestListTemplates(unittest.TestCase):
                 'http://example.com/goodbye',
                 'a user', 'the password',
                 )
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/lists/ant.example.com/uris')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(resource['start'], 0)
-        self.assertEqual(resource['total_size'], 2)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json['start'], 0)
+        self.assertEqual(json['total_size'], 2)
         self.assertEqual(
-            resource['self_link'],
+            json['self_link'],
             'http://localhost:9001/3.1/lists/ant.example.com/uris')
-        self.assertEqual(resource['entries'], [
+        self.assertEqual(json['entries'], [
             {'http_etag': '"6612187ed6604ce54a57405fd66742557391ed4a"',
              'name': 'list:user:notice:goodbye',
              'password': 'the password',
@@ -613,12 +616,12 @@ class TestListTemplates(unittest.TestCase):
              }])
 
     def test_patch_uris(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/lists/ant.example.com/uris', {
                 'list:user:notice:welcome': 'http://example.org/welcome',
                 'list:user:notice:goodbye': 'http://example.org/goodbye',
                 }, method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         manager = getUtility(ITemplateManager)
         template = manager.raw('list:user:notice:welcome', 'ant.example.com')
         self.assertEqual(template.uri, 'http://example.org/welcome')
@@ -630,14 +633,14 @@ class TestListTemplates(unittest.TestCase):
         self.assertEqual(template.password, '')
 
     def test_patch_uris_with_credentials(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/lists/ant.example.com/uris', {
                 'list:user:notice:welcome': 'http://example.org/welcome',
                 'list:user:notice:goodbye': 'http://example.org/goodbye',
                 'password': 'some password',
                 'username': 'anne.person',
                 }, method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         manager = getUtility(ITemplateManager)
         template = manager.raw('list:user:notice:welcome', 'ant.example.com')
         self.assertEqual(template.uri, 'http://example.org/welcome')
@@ -659,7 +662,7 @@ class TestListTemplates(unittest.TestCase):
         self.assertEqual(cm.exception.code, 400)
 
     def test_put_all_uris(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/lists/ant.example.com/uris', {
                 'list:admin:action:post': '',
                 'list:admin:action:subscribe': '',
@@ -684,7 +687,7 @@ class TestListTemplates(unittest.TestCase):
                 'password': 'some password',
                 'username': 'anne.person',
                 }, method='PUT')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         manager = getUtility(ITemplateManager)
         template = manager.raw('list:member:digest:footer', 'ant.example.com')
         self.assertIsNone(template)
@@ -718,10 +721,10 @@ class TestListTemplates(unittest.TestCase):
                 'http://example.com/goodbye',
                 'a user', 'the password',
                 )
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/lists/ant.example.com/uris',
             method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertIsNone(
             manager.raw('list:user:notice:welcome', 'ant.example.com'))
         self.assertIsNone(
@@ -732,11 +735,11 @@ class TestListTemplates(unittest.TestCase):
             getUtility(ITemplateManager).set(
                 'list:user:notice:welcome', 'ant.example.com',
                 'http://example.com/welcome')
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/lists/ant.example.com/uris'
             '/list:user:notice:welcome')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(resource, {
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json, {
             'http_etag': '"36f8bef800cfd278f097c61c5892a34c0650f4aa"',
             'self_link': ('http://localhost:9001/3.1/lists/ant.example.com'
                           '/uris/list:user:notice:welcome'),
diff --git a/src/mailman/rest/tests/test_membership.py b/src/mailman/rest/tests/test_membership.py
index d5251ca9d..6b4f5195a 100644
--- a/src/mailman/rest/tests/test_membership.py
+++ b/src/mailman/rest/tests/test_membership.py
@@ -53,7 +53,7 @@ class TestMembership(unittest.TestCase):
                 'subscriber': 'nobody@example.com',
                 })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'No such list')
+        self.assertEqual(cm.exception.reason, 'No such list')
 
     def test_try_to_leave_missing_list(self):
         # A user tries to leave a non-existent list.
@@ -74,11 +74,11 @@ class TestMembership(unittest.TestCase):
             anne = self._usermanager.create_address('anne@example.com')
             self._mlist.subscribe(anne)
         url = 'http://localhost:9001/3.0/members/1'
-        content, response = call_api(url, method='DELETE')
+        json, response = call_api(url, method='DELETE')
         # For a successful DELETE, the response code is 204 and there is no
         # content.
-        self.assertEqual(content, None)
-        self.assertEqual(response.status, 204)
+        self.assertEqual(json, None)
+        self.assertEqual(response.status_code, 204)
         with self.assertRaises(HTTPError) as cm:
             call_api(url, method='DELETE')
         self.assertEqual(cm.exception.code, 404)
@@ -96,7 +96,7 @@ class TestMembership(unittest.TestCase):
                 'pre_approved': True,
                 })
         self.assertEqual(cm.exception.code, 409)
-        self.assertEqual(cm.exception.reason, b'Member already subscribed')
+        self.assertEqual(cm.exception.reason, 'Member already subscribed')
 
     def test_subscribe_user_without_preferred_address(self):
         with transaction():
@@ -111,7 +111,7 @@ class TestMembership(unittest.TestCase):
                 'pre_approved': True,
                 })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'User has no preferred address')
+        self.assertEqual(cm.exception.reason, 'User has no preferred address')
 
     def test_subscribe_bogus_user_by_uid(self):
         with self.assertRaises(HTTPError) as cm:
@@ -123,7 +123,7 @@ class TestMembership(unittest.TestCase):
                 'pre_approved': True,
                 })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'No such user')
+        self.assertEqual(cm.exception.reason, 'No such user')
 
     def test_add_member_with_mixed_case_email(self):
         # LP: #1425359 - Mailman is case-perserving, case-insensitive.  This
@@ -141,7 +141,7 @@ class TestMembership(unittest.TestCase):
                 'pre_approved': True,
                 })
         self.assertEqual(cm.exception.code, 409)
-        self.assertEqual(cm.exception.reason, b'Member already subscribed')
+        self.assertEqual(cm.exception.reason, 'Member already subscribed')
 
     def test_add_member_with_lower_case_email(self):
         # LP: #1425359 - Mailman is case-perserving, case-insensitive.  This
@@ -159,7 +159,7 @@ class TestMembership(unittest.TestCase):
                 'pre_approved': True,
                 })
         self.assertEqual(cm.exception.code, 409)
-        self.assertEqual(cm.exception.reason, b'Member already subscribed')
+        self.assertEqual(cm.exception.reason, 'Member already subscribed')
 
     def test_join_with_invalid_delivery_mode(self):
         with self.assertRaises(HTTPError) as cm:
@@ -171,10 +171,10 @@ class TestMembership(unittest.TestCase):
                 })
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Cannot convert parameters: delivery_mode')
+                         'Cannot convert parameters: delivery_mode')
 
     def test_join_email_contains_slash(self):
-        content, response = call_api('http://localhost:9001/3.0/members', {
+        json, response = call_api('http://localhost:9001/3.0/members', {
             'list_id': 'test.example.com',
             'subscriber': 'hugh/person@example.com',
             'display_name': 'Hugh Person',
@@ -182,9 +182,9 @@ class TestMembership(unittest.TestCase):
             'pre_confirmed': True,
             'pre_approved': True,
             })
-        self.assertEqual(content, None)
-        self.assertEqual(response.status, 201)
-        self.assertEqual(response['location'],
+        self.assertEqual(json, None)
+        self.assertEqual(response.status_code, 201)
+        self.assertEqual(response.headers['location'],
                          'http://localhost:9001/3.0/members/1')
         # Reset any current transaction.
         config.db.abort()
@@ -197,10 +197,10 @@ class TestMembership(unittest.TestCase):
             anne = self._usermanager.create_user('anne@example.com')
             set_preferred(anne)
             self._mlist.subscribe(anne)
-        content, response = call_api('http://localhost:9001/3.0/members')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(int(content['total_size']), 1)
-        entry_0 = content['entries'][0]
+        json, response = call_api('http://localhost:9001/3.0/members')
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(int(json['total_size']), 1)
+        entry_0 = json['entries'][0]
         self.assertEqual(entry_0['self_link'],
                          'http://localhost:9001/3.0/members/1')
         self.assertEqual(entry_0['role'], 'member')
@@ -231,7 +231,7 @@ class TestMembership(unittest.TestCase):
                 })
         self.assertEqual(cm.exception.code, 409)
         self.assertEqual(cm.exception.reason,
-                         b'Subscription request already pending')
+                         'Subscription request already pending')
 
     def test_duplicate_other_pending_subscription(self):
         # Issue #199 - a member's subscription is already pending and they try
@@ -255,7 +255,7 @@ class TestMembership(unittest.TestCase):
                 })
         self.assertEqual(cm.exception.code, 409)
         self.assertEqual(cm.exception.reason,
-                         b'Subscription request already pending')
+                         'Subscription request already pending')
 
     def test_member_changes_preferred_address(self):
         with transaction():
@@ -263,9 +263,9 @@ class TestMembership(unittest.TestCase):
             set_preferred(anne)
             self._mlist.subscribe(anne)
         # Take a look at Anne's current membership.
-        content, response = call_api('http://localhost:9001/3.0/members')
-        self.assertEqual(int(content['total_size']), 1)
-        entry_0 = content['entries'][0]
+        json, response = call_api('http://localhost:9001/3.0/members')
+        self.assertEqual(int(json['total_size']), 1)
+        entry_0 = json['entries'][0]
         self.assertEqual(entry_0['email'], 'anne@example.com')
         self.assertEqual(
             entry_0['address'],
@@ -277,9 +277,9 @@ class TestMembership(unittest.TestCase):
             new_preferred.verified_on = now()
             anne.preferred_address = new_preferred
         # Take another look at Anne's current membership.
-        content, response = call_api('http://localhost:9001/3.0/members')
-        self.assertEqual(int(content['total_size']), 1)
-        entry_0 = content['entries'][0]
+        json, response = call_api('http://localhost:9001/3.0/members')
+        self.assertEqual(int(json['total_size']), 1)
+        entry_0 = json['entries'][0]
         self.assertEqual(entry_0['email'], 'aperson@example.com')
         self.assertEqual(
             entry_0['address'],
@@ -307,7 +307,7 @@ class TestMembership(unittest.TestCase):
                 'address': 'bogus@example.com',
                 }, method='PATCH')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Address not registered')
+        self.assertEqual(cm.exception.reason, 'Address not registered')
 
     def test_patch_membership_with_unverified_address(self):
         # Try to change a subscription address to one that is not yet verified.
@@ -319,7 +319,7 @@ class TestMembership(unittest.TestCase):
                 'address': 'anne.person@example.com',
                 }, method='PATCH')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Unverified address')
+        self.assertEqual(cm.exception.reason, 'Unverified address')
 
     def test_patch_membership_of_preferred_address(self):
         # Try to change a subscription to an address when the user is
@@ -334,7 +334,7 @@ class TestMembership(unittest.TestCase):
                 }, method='PATCH')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Address is not controlled by user')
+                         'Address is not controlled by user')
 
     def test_patch_member_bogus_attribute(self):
         # /members/<id> PATCH 'bogus' returns 400
@@ -346,7 +346,7 @@ class TestMembership(unittest.TestCase):
                      'powers': 'super',
                      }, method='PATCH')
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Unexpected parameters: powers')
+        self.assertEqual(cm.exception.reason, 'Unexpected parameters: powers')
 
     def test_member_all_without_preferences(self):
         # /members/<id>/all should return a 404 when it isn't trailed by
@@ -366,7 +366,7 @@ class TestMembership(unittest.TestCase):
                      }, method='PATCH')
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'Cannot convert parameters: moderation_action')
+                         'Cannot convert parameters: moderation_action')
 
     def test_bad_preferences_url(self):
         with transaction():
@@ -388,10 +388,10 @@ class TestMembership(unittest.TestCase):
     def test_delete_other_role(self):
         with transaction():
             subscribe(self._mlist, 'Anne', MemberRole.moderator)
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/members/1',
             method='DELETE')
-        self.assertEqual(headers.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(len(list(self._mlist.moderators.members)), 0)
 
     def test_banned_member_tries_to_join(self):
@@ -404,7 +404,7 @@ class TestMembership(unittest.TestCase):
                 'subscriber': 'anne@example.com',
                 })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Membership is banned')
+        self.assertEqual(cm.exception.reason, 'Membership is banned')
 
     def test_globally_banned_member_tries_to_join(self):
         # A user tries to join a list they are banned from.
@@ -416,7 +416,7 @@ class TestMembership(unittest.TestCase):
                 'subscriber': 'anne@example.com',
                 })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Membership is banned')
+        self.assertEqual(cm.exception.reason, 'Membership is banned')
 
 
 class CustomLayer(ConfigLayer):
@@ -475,13 +475,13 @@ Message-ID: <alpha>
 Some text.
 """)
         # Now use the REST API to try to find the nonmember.
-        response, content = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/members/find', {
                 # 'list_id': 'test.example.com',
                 'role': 'nonmember',
                 })
-        self.assertEqual(response['total_size'], 1)
-        nonmember = response['entries'][0]
+        self.assertEqual(json['total_size'], 1)
+        nonmember = json['entries'][0]
         self.assertEqual(nonmember['role'], 'nonmember')
         self.assertEqual(nonmember['email'], 'nonmember@example.com')
         self.assertEqual(
@@ -506,13 +506,13 @@ Message-ID: <alpha>
 Some text.
 """)
         # Now use the REST API to try to find the nonmember.
-        response, content = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/members/find', {
                 # 'list_id': 'test.example.com',
                 'role': 'nonmember',
                 })
-        self.assertEqual(response['total_size'], 1)
-        nonmember = response['entries'][0]
+        self.assertEqual(json['total_size'], 1)
+        nonmember = json['entries'][0]
         self.assertEqual(nonmember['role'], 'nonmember')
         self.assertEqual(nonmember['email'], 'nonmember@example.com')
         self.assertEqual(
@@ -535,8 +535,8 @@ class TestAPI31Members(unittest.TestCase):
         with transaction():
             subscribe(self._mlist, 'Anne')
             subscribe(self._mlist, 'Bart')
-        response, headers = call_api('http://localhost:9001/3.1/members')
-        entries = response['entries']
+        json, response = call_api('http://localhost:9001/3.1/members')
+        entries = json['entries']
         self.assertEqual(len(entries), 2)
         self.assertEqual(
           entries[0]['self_link'],
@@ -560,37 +560,38 @@ class TestAPI31Members(unittest.TestCase):
     def test_get_member_id_by_hex(self):
         with transaction():
             subscribe(self._mlist, 'Anne')
-        response, headers = call_api(
+        json, response = call_api(
           'http://localhost:9001/3.1/members/00000000000000000000000000000001')
         self.assertEqual(
-            response['member_id'],
+            json['member_id'],
             '00000000000000000000000000000001')
         self.assertEqual(
-          response['self_link'],
+          json['self_link'],
           'http://localhost:9001/3.1/members/00000000000000000000000000000001')
         self.assertEqual(
-            response['user'],
+            json['user'],
             'http://localhost:9001/3.1/users/00000000000000000000000000000001')
         self.assertEqual(
-            response['address'],
+            json['address'],
             'http://localhost:9001/3.1/addresses/aperson@example.com')
 
     def test_get_list_member_id_by_email(self):
         with transaction():
             subscribe(self._mlist, 'Anne', email="aperson@example.com")
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/lists/ant.example.com/member'
             '/aperson@example.com')
-        self.assertEqual(response['member_id'],
-                         '00000000000000000000000000000001')
         self.assertEqual(
-          response['self_link'],
+            json['member_id'],
+            '00000000000000000000000000000001')
+        self.assertEqual(
+          json['self_link'],
           'http://localhost:9001/3.1/members/00000000000000000000000000000001')
         self.assertEqual(
-            response['user'],
+            json['user'],
             'http://localhost:9001/3.1/users/00000000000000000000000000000001')
         self.assertEqual(
-            response['address'],
+            json['address'],
             'http://localhost:9001/3.1/addresses/aperson@example.com')
 
     def test_cannot_get_member_id_by_int(self):
@@ -604,26 +605,26 @@ class TestAPI31Members(unittest.TestCase):
         with transaction():
             member = subscribe(self._mlist, 'Anne')
             member.preferences.delivery_mode = DeliveryMode.summary_digests
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/members'
             '/00000000000000000000000000000001/preferences')
-        self.assertEqual(response['delivery_mode'], 'summary_digests')
+        self.assertEqual(json['delivery_mode'], 'summary_digests')
 
     def test_all_preferences(self):
         with transaction():
             member = subscribe(self._mlist, 'Anne')
             member.preferences.delivery_mode = DeliveryMode.summary_digests
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/members'
             '/00000000000000000000000000000001/all/preferences')
-        self.assertEqual(response['delivery_mode'], 'summary_digests')
+        self.assertEqual(json['delivery_mode'], 'summary_digests')
 
     def test_create_new_membership_by_hex(self):
         with transaction():
             user = getUtility(IUserManager).create_user('anne@example.com')
             set_preferred(user)
         # Subscribe the user to the mailing list by hex UUID.
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/members', {
                 'list_id': 'ant.example.com',
                 'subscriber': '00000000000000000000000000000001',
@@ -631,9 +632,9 @@ class TestAPI31Members(unittest.TestCase):
                 'pre_confirmed': True,
                 'pre_approved': True,
                 })
-        self.assertEqual(headers.status, 201)
+        self.assertEqual(response.status_code, 201)
         self.assertEqual(
-           headers['location'],
+           response.headers['location'],
            'http://localhost:9001/3.1/members/00000000000000000000000000000001'
            )
 
@@ -642,15 +643,15 @@ class TestAPI31Members(unittest.TestCase):
             user = getUtility(IUserManager).create_user('anne@example.com')
             set_preferred(user)
         # Subscribe the user to the mailing list by hex UUID.
-        response, headers = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/members', {
                 'list_id': 'ant.example.com',
                 'subscriber': '00000000000000000000000000000001',
                 'role': 'owner',
                 })
-        self.assertEqual(headers.status, 201)
+        self.assertEqual(response.status_code, 201)
         self.assertEqual(
-           headers['location'],
+           response.headers['location'],
            'http://localhost:9001/3.1/members/00000000000000000000000000000001'
            )
 
@@ -686,4 +687,4 @@ class TestAPI31Members(unittest.TestCase):
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(
             cm.exception.reason,
-            b'anne@example.com is already an owner of ant@example.com')
+            'anne@example.com is already an owner of ant@example.com')
diff --git a/src/mailman/rest/tests/test_moderation.py b/src/mailman/rest/tests/test_moderation.py
index 3d3b234c7..0a9bb2608 100644
--- a/src/mailman/rest/tests/test_moderation.py
+++ b/src/mailman/rest/tests/test_moderation.py
@@ -96,7 +96,7 @@ Something else.
             call_api(url.format(held_id), {'action': 'bogus'})
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.msg,
-                         b'Cannot convert parameters: action')
+                         'Cannot convert parameters: action')
 
     def test_discard(self):
         # Discarding a message removes it from the moderation queue.
@@ -104,8 +104,8 @@ Something else.
             held_id = hold_message(self._mlist, self._msg)
         url = 'http://localhost:9001/3.0/lists/ant@example.com/held/{}'.format(
             held_id)
-        content, response = call_api(url, dict(action='discard'))
-        self.assertEqual(response.status, 204)
+        json, response = call_api(url, dict(action='discard'))
+        self.assertEqual(response.status_code, 204)
         # Now it's gone.
         with self.assertRaises(HTTPError) as cm:
             call_api(url, dict(action='discard'))
@@ -115,11 +115,11 @@ Something else.
         # We can view all the held requests.
         with transaction():
             held_id = hold_message(self._mlist, self._msg)
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant@example.com/held')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(content['total_size'], 1)
-        self.assertEqual(content['entries'][0]['request_id'], held_id)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json['total_size'], 1)
+        self.assertEqual(json['entries'][0]['request_id'], held_id)
 
     def test_cant_get_other_lists_holds(self):
         # Issue #161: It was possible to moderate a held message for another
@@ -187,7 +187,7 @@ class TestSubscriptionModeration(unittest.TestCase):
                 ))
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.msg,
-                         b'Cannot convert parameters: action')
+                         'Cannot convert parameters: action')
 
     def test_list_held_requests(self):
         # We can view all the held requests.
@@ -199,13 +199,13 @@ class TestSubscriptionModeration(unittest.TestCase):
             token_2, token_owner, member = self._registrar.register(self._bart)
             self.assertIsNotNone(token_2)
             self.assertIsNone(member)
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant@example.com/requests')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(content['total_size'], 2)
-        tokens = set(json['token'] for json in content['entries'])
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json['total_size'], 2)
+        tokens = set(entry['token'] for entry in json['entries'])
         self.assertEqual(tokens, {token_1, token_2})
-        emails = set(json['email'] for json in content['entries'])
+        emails = set(entry['email'] for entry in json['entries'])
         self.assertEqual(emails, {'anne@example.com', 'bart@example.com'})
 
     def test_view_malformed_held_message(self):
@@ -219,11 +219,11 @@ class TestSubscriptionModeration(unittest.TestCase):
             hold_message(self._mlist, msg)
         # Now trying to access held messages from REST API should not give
         # 500 server error if one of the messages can't be parsed properly.
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant@example.com/held')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(len(content['entries']), 1)
-        self.assertEqual(content['entries'][0]['msg'],
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(len(json['entries']), 1)
+        self.assertEqual(json['entries'][0]['msg'],
                          'This message is defective')
 
     def test_individual_request(self):
@@ -234,11 +234,11 @@ class TestSubscriptionModeration(unittest.TestCase):
             self.assertIsNotNone(token)
             self.assertIsNone(member)
         url = 'http://localhost:9001/3.0/lists/ant@example.com/requests/{}'
-        content, response = call_api(url.format(token))
-        self.assertEqual(response.status, 200)
-        self.assertEqual(content['token'], token)
-        self.assertEqual(content['token_owner'], token_owner.name)
-        self.assertEqual(content['email'], 'anne@example.com')
+        json, response = call_api(url.format(token))
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json['token'], token)
+        self.assertEqual(json['token_owner'], token_owner.name)
+        self.assertEqual(json['email'], 'anne@example.com')
 
     def test_accept(self):
         # POST to the request to accept it.
@@ -247,10 +247,10 @@ class TestSubscriptionModeration(unittest.TestCase):
         # Anne's subscription request got held.
         self.assertIsNone(member)
         url = 'http://localhost:9001/3.0/lists/ant@example.com/requests/{}'
-        content, response = call_api(url.format(token), dict(
+        json, response = call_api(url.format(token), dict(
             action='accept',
             ))
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Anne is a member.
         self.assertEqual(
             self._mlist.members.get_member('anne@example.com').address,
@@ -275,7 +275,7 @@ class TestSubscriptionModeration(unittest.TestCase):
                 action='accept',
                 ))
         self.assertEqual(cm.exception.code, 409)
-        self.assertEqual(cm.exception.reason, b'Already subscribed')
+        self.assertEqual(cm.exception.reason, 'Already subscribed')
 
     def test_accept_bad_token(self):
         # Try to accept a request with a bogus token.
@@ -290,9 +290,9 @@ class TestSubscriptionModeration(unittest.TestCase):
         # more requests to handle.
         #
         # We start with nothing in the queue.
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant@example.com/requests')
-        self.assertEqual(content['total_size'], 0)
+        self.assertEqual(json['total_size'], 0)
         # Anne tries to subscribe to a list that only requests moderator
         # approval.
         with transaction():
@@ -302,20 +302,20 @@ class TestSubscriptionModeration(unittest.TestCase):
                 pre_verified=True, pre_confirmed=True)
         # There's now one request in the queue, and it's waiting on moderator
         # approval.
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant@example.com/requests')
-        self.assertEqual(content['total_size'], 1)
-        json = content['entries'][0]
-        self.assertEqual(json['token_owner'], 'moderator')
-        self.assertEqual(json['email'], 'anne@example.com')
+        self.assertEqual(json['total_size'], 1)
+        entry = json['entries'][0]
+        self.assertEqual(entry['token_owner'], 'moderator')
+        self.assertEqual(entry['email'], 'anne@example.com')
         # The moderator approves the request.
         url = 'http://localhost:9001/3.0/lists/ant@example.com/requests/{}'
-        content, response = call_api(url.format(token), {'action': 'accept'})
-        self.assertEqual(response.status, 204)
+        json, response = call_api(url.format(token), {'action': 'accept'})
+        self.assertEqual(response.status_code, 204)
         # And now the request queue is empty.
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/lists/ant@example.com/requests')
-        self.assertEqual(content['total_size'], 0)
+        self.assertEqual(json['total_size'], 0)
 
     def test_discard(self):
         # POST to the request to discard it.
@@ -324,10 +324,10 @@ class TestSubscriptionModeration(unittest.TestCase):
         # Anne's subscription request got held.
         self.assertIsNone(member)
         url = 'http://localhost:9001/3.0/lists/ant@example.com/requests/{}'
-        content, response = call_api(url.format(token), dict(
+        json, response = call_api(url.format(token), dict(
             action='discard',
             ))
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Anne is not a member.
         self.assertIsNone(self._mlist.members.get_member('anne@example.com'))
         # The request URL no longer exists.
@@ -344,22 +344,22 @@ class TestSubscriptionModeration(unittest.TestCase):
         # Anne's subscription request got held.
         self.assertIsNone(member)
         url = 'http://localhost:9001/3.0/lists/ant@example.com/requests/{}'
-        content, response = call_api(url.format(token), dict(
+        json, response = call_api(url.format(token), dict(
             action='defer',
             ))
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Anne is not a member.
         self.assertIsNone(self._mlist.members.get_member('anne@example.com'))
         # The request URL still exists.
-        content, response = call_api(url.format(token), dict(
+        json, response = call_api(url.format(token), dict(
             action='defer',
             ))
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # And now we can accept it.
-        content, response = call_api(url.format(token), dict(
+        json, response = call_api(url.format(token), dict(
             action='accept',
             ))
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Anne is a member.
         self.assertEqual(
             self._mlist.members.get_member('anne@example.com').address,
@@ -390,10 +390,10 @@ class TestSubscriptionModeration(unittest.TestCase):
         # confirmation message sent to Anne.
         get_queue_messages('virgin')
         url = 'http://localhost:9001/3.0/lists/ant@example.com/requests/{}'
-        content, response = call_api(url.format(token), dict(
+        json, response = call_api(url.format(token), dict(
             action='reject',
             ))
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Anne is not a member.
         self.assertIsNone(self._mlist.members.get_member('anne@example.com'))
         # The request URL no longer exists.
@@ -429,17 +429,17 @@ class TestSubscriptionModeration(unittest.TestCase):
         # confirmation message sent to Anne.
         get_queue_messages('virgin')
         url = 'http://localhost:9001/3.0/lists/ant@example.com/requests/{}'
-        content, response = call_api(url.format(token), dict(
+        json, response = call_api(url.format(token), dict(
             action='hold',
             ))
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Anne is not a member.
         self.assertIsNone(self._mlist.members.get_member('anne@example.com'))
         # The request URL still exists.
-        content, response = call_api(url.format(token), dict(
+        json, response = call_api(url.format(token), dict(
                 action='defer',
                 ))
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
 
     def test_subscribe_other_role_with_no_preferred_address(self):
         with transaction():
@@ -451,8 +451,7 @@ class TestSubscriptionModeration(unittest.TestCase):
                 'role': 'moderator',
                 })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason,
-                         b'User without preferred address')
+        self.assertEqual(cm.exception.reason, 'User without preferred address')
 
     def test_subscribe_other_role_banned_email_address(self):
         bans = IBanManager(self._mlist)
@@ -465,4 +464,4 @@ class TestSubscriptionModeration(unittest.TestCase):
                 'role': 'moderator',
                 })
         self.assertEqual(cm.exception.code, 400)
-        self.assertEqual(cm.exception.reason, b'Membership is banned')
+        self.assertEqual(cm.exception.reason, 'Membership is banned')
diff --git a/src/mailman/rest/tests/test_queues.py b/src/mailman/rest/tests/test_queues.py
index 7a5a7e134..b6668bdff 100644
--- a/src/mailman/rest/tests/test_queues.py
+++ b/src/mailman/rest/tests/test_queues.py
@@ -65,8 +65,8 @@ class TestQueues(unittest.TestCase):
         content, response = call_api('http://localhost:9001/3.0/queues/bad', {
             'list_id': 'test.example.com',
             'text': TEXT})
-        self.assertEqual(response.status, 201)
-        location = response['location']
+        self.assertEqual(response.status_code, 201)
+        location = response.headers['location']
         filebase = location.split('/')[-1]
         # The message is in the 'bad' queue.
         content, response = call_api('http://localhost:9001/3.0/queues/bad')
@@ -94,9 +94,9 @@ class TestQueues(unittest.TestCase):
         content, response = call_api('http://localhost:9001/3.0/queues/bad', {
             'list_id': 'test.example.com',
             'text': TEXT})
-        location = response['location']
+        location = response.headers['location']
         self.assertEqual(len(config.switchboards['bad'].files), 1)
         # Delete the file through REST.
         content, response = call_api(location, method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertEqual(len(config.switchboards['bad'].files), 0)
diff --git a/src/mailman/rest/tests/test_root.py b/src/mailman/rest/tests/test_root.py
index dd6808efc..cb16caeeb 100644
--- a/src/mailman/rest/tests/test_root.py
+++ b/src/mailman/rest/tests/test_root.py
@@ -18,11 +18,9 @@
 """REST root object tests."""
 
 import os
-import json
+import requests
 import unittest
 
-from base64 import b64encode
-from httplib2 import Http
 from mailman.config import config
 from mailman.core.system import system
 from mailman.database.transaction import transaction
@@ -94,32 +92,21 @@ class TestRoot(unittest.TestCase):
 
     def test_no_basic_auth(self):
         # If Basic Auth credentials are missing, it is a 401 error.
-        url = 'http://localhost:9001/3.0/system'
-        headers = {
-            'Content-Type': 'application/x-www-form-urlencode',
-            }
-        response, raw_content = Http().request(url, 'GET', None, headers)
-        self.assertEqual(response.status, 401)
-        content = json.loads(raw_content.decode('utf-8'))
-        self.assertEqual(content['title'], '401 Unauthorized')
-        self.assertEqual(content['description'],
-                         'REST API authorization failed')
+        response = requests.get('http://localhost:9001/3.0/system')
+        self.assertEqual(response.status_code, 401)
+        json = response.json()
+        self.assertEqual(json['title'], '401 Unauthorized')
+        self.assertEqual(json['description'], 'REST API authorization failed')
 
     def test_unauthorized(self):
         # Bad Basic Auth credentials results in a 401 error.
-        userpass = b64encode(b'baduser:badpass')
-        auth = 'Basic {}'.format(userpass.decode('ascii'))
-        url = 'http://localhost:9001/3.0/system'
-        headers = {
-            'Content-Type': 'application/x-www-form-urlencode',
-            'Authorization': auth,
-            }
-        response, raw_content = Http().request(url, 'GET', None, headers)
-        self.assertEqual(response.status, 401)
-        content = json.loads(raw_content.decode('utf-8'))
-        self.assertEqual(content['title'], '401 Unauthorized')
-        self.assertEqual(content['description'],
-                         'REST API authorization failed')
+        response = requests.get(
+            'http://localhost:9001/3.0/system',
+            auth=('baduser', 'badpass'))
+        self.assertEqual(response.status_code, 401)
+        json = response.json()
+        self.assertEqual(json['title'], '401 Unauthorized')
+        self.assertEqual(json['description'], 'REST API authorization failed')
 
     def test_reserved_bad_subpath(self):
         # Only <api>/reserved/uids/orphans is a defined resource.  DELETEing
@@ -203,15 +190,15 @@ class TestSiteTemplates(unittest.TestCase):
                 'http://example.com/goodbye',
                 'a user', 'the password',
                 )
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/uris')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(resource['start'], 0)
-        self.assertEqual(resource['total_size'], 2)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json['start'], 0)
+        self.assertEqual(json['total_size'], 2)
         self.assertEqual(
-            resource['self_link'],
+            json['self_link'],
             'http://localhost:9001/3.1/uris')
-        self.assertEqual(resource['entries'], [
+        self.assertEqual(json['entries'], [
             {'http_etag': '"063fd6635a6035a4b7e939a304fcbd16571aa662"',
              'name': 'list:user:notice:goodbye',
              'password': 'the password',
@@ -228,12 +215,12 @@ class TestSiteTemplates(unittest.TestCase):
              }])
 
     def test_patch_uris(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/uris', {
                 'list:user:notice:welcome': 'http://example.org/welcome',
                 'list:user:notice:goodbye': 'http://example.org/goodbye',
                 }, method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         manager = getUtility(ITemplateManager)
         template = manager.raw('list:user:notice:welcome', None)
         self.assertEqual(template.uri, 'http://example.org/welcome')
@@ -245,14 +232,14 @@ class TestSiteTemplates(unittest.TestCase):
         self.assertEqual(template.password, '')
 
     def test_patch_uris_with_credentials(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/uris', {
                 'list:user:notice:welcome': 'http://example.org/welcome',
                 'list:user:notice:goodbye': 'http://example.org/goodbye',
                 'password': 'some password',
                 'username': 'anne.person',
                 }, method='PATCH')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         manager = getUtility(ITemplateManager)
         template = manager.raw('list:user:notice:welcome', None)
         self.assertEqual(template.uri, 'http://example.org/welcome')
@@ -274,7 +261,7 @@ class TestSiteTemplates(unittest.TestCase):
         self.assertEqual(cm.exception.code, 400)
 
     def test_put_all_uris(self):
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/uris', {
                 'domain:admin:notice:new-list': '',
                 'list:admin:action:post': '',
@@ -300,7 +287,7 @@ class TestSiteTemplates(unittest.TestCase):
                 'password': 'some password',
                 'username': 'anne.person',
                 }, method='PUT')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         manager = getUtility(ITemplateManager)
         template = manager.raw('list:member:digest:footer', None)
         self.assertIsNone(template)
@@ -334,10 +321,10 @@ class TestSiteTemplates(unittest.TestCase):
                 'http://example.com/goodbye',
                 'a user', 'the password',
                 )
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/uris',
             method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         self.assertIsNone(manager.raw('list:user:notice:welcome', None))
         self.assertIsNone(manager.raw('list:user:notice:goodbye', None))
 
@@ -346,10 +333,10 @@ class TestSiteTemplates(unittest.TestCase):
             getUtility(ITemplateManager).set(
                 'list:user:notice:welcome', None,
                 'http://example.com/welcome')
-        resource, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/uris/list:user:notice:welcome')
-        self.assertEqual(response.status, 200)
-        self.assertEqual(resource, {
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json, {
             'http_etag': '"86e360d83197561d50826ad6d15e9c30923b82d6"',
             'self_link': ('http://localhost:9001/3.1'
                           '/uris/list:user:notice:welcome'),
diff --git a/src/mailman/rest/tests/test_uids.py b/src/mailman/rest/tests/test_uids.py
index 79f5b73b3..c2a4fcf1c 100644
--- a/src/mailman/rest/tests/test_uids.py
+++ b/src/mailman/rest/tests/test_uids.py
@@ -64,7 +64,7 @@ class TestUIDs(unittest.TestCase):
         content, response = call_api(
             'http://localhost:9001/3.0/reserved/uids/orphans',
             method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Now there are no uids in the table.
         config.db.abort()
         self.assertEqual(UID.get_total_uid_count(), 0)
diff --git a/src/mailman/rest/tests/test_users.py b/src/mailman/rest/tests/test_users.py
index 60d748a6f..97f4b76d2 100644
--- a/src/mailman/rest/tests/test_users.py
+++ b/src/mailman/rest/tests/test_users.py
@@ -104,10 +104,10 @@ class TestUsers(unittest.TestCase):
             anne = getUtility(IUserManager).create_user(
                 'anne@example.com', 'Anne Person')
             user_id = anne.user_id
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com',
             method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/users/anne@example.com',
                      method='DELETE')
@@ -124,14 +124,14 @@ class TestUsers(unittest.TestCase):
                 'anne@example.com', 'Anne Person')
             user_id = anne.user_id
         # You can still GET the user record.
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com')
-        self.assertEqual(response.status, 200)
+        self.assertEqual(response.status_code, 200)
         # Delete the user.
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com',
             method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # The user record can no longer be retrieved.
         with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/users/anne@example.com')
@@ -152,7 +152,7 @@ class TestUsers(unittest.TestCase):
                      })
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'User already exists: anne@example.com')
+                         'User already exists: anne@example.com')
 
     def test_addresses_of_missing_user_id(self):
         # Trying to get the /addresses of a missing user id results in error.
@@ -218,29 +218,29 @@ class TestUsers(unittest.TestCase):
     def test_create_user_twice(self):
         # LP: #1418280.  No additional users should be created when an address
         # that already exists is given.
-        content, response = call_api('http://localhost:9001/3.0/users')
-        self.assertEqual(content['total_size'], 0)
+        json, response = call_api('http://localhost:9001/3.0/users')
+        self.assertEqual(json['total_size'], 0)
         # Create the user.
         call_api('http://localhost:9001/3.0/users', dict(
             email='anne@example.com'))
         # There is now one user.
-        content, response = call_api('http://localhost:9001/3.0/users')
-        self.assertEqual(content['total_size'], 1)
+        json, response = call_api('http://localhost:9001/3.0/users')
+        self.assertEqual(json['total_size'], 1)
         # Trying to create the user with the same address results in an error.
         with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/users', dict(
                 email='anne@example.com'))
         self.assertEqual(cm.exception.code, 400)
         self.assertEqual(cm.exception.reason,
-                         b'User already exists: anne@example.com')
+                         'User already exists: anne@example.com')
         # But at least no new users was created.
-        content, response = call_api('http://localhost:9001/3.0/users')
-        self.assertEqual(content['total_size'], 1)
+        json, response = call_api('http://localhost:9001/3.0/users')
+        self.assertEqual(json['total_size'], 1)
 
     def test_create_server_owner_false(self):
         # Issue #136: Creating a user with is_server_owner=no should create
         # user who is not a server owner.
-        content, response = call_api('http://localhost:9001/3.0/users', dict(
+        json, response = call_api('http://localhost:9001/3.0/users', dict(
             email='anne@example.com',
             is_server_owner='no'))
         anne = getUtility(IUserManager).get_user('anne@example.com')
@@ -249,7 +249,7 @@ class TestUsers(unittest.TestCase):
     def test_create_server_owner_true(self):
         # Issue #136: Creating a user with is_server_owner=yes should create a
         # new server owner user.
-        content, response = call_api('http://localhost:9001/3.0/users', dict(
+        json, response = call_api('http://localhost:9001/3.0/users', dict(
             email='anne@example.com',
             is_server_owner='yes'))
         anne = getUtility(IUserManager).get_user('anne@example.com')
@@ -274,10 +274,10 @@ class TestUsers(unittest.TestCase):
             id=anne.preferences.id)
         self.assertEqual(preferences.count(), 1)
         # Delete the user via REST.
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com',
             method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # The user's preference has been deleted.
         with transaction():
             preferences = config.db.store.query(Preferences).filter_by(
@@ -288,10 +288,10 @@ class TestUsers(unittest.TestCase):
         with transaction():
             user = getUtility(IUserManager).create_user('anne@example.com')
             user.preferences.delivery_mode = DeliveryMode.summary_digests
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/1/preferences')
         self.assertEqual(
-            content['self_link'],
+            json['self_link'],
             'http://localhost:9001/3.0/users/1/preferences')
 
 
@@ -309,11 +309,11 @@ class TestLogin(unittest.TestCase):
 
     def test_login_with_cleartext_password(self):
         # A user can log in with the correct clear text password.
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com/login', {
                 'cleartext_password': 'abc123',
                 }, method='POST')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # But the user cannot log in with an incorrect password.
         with self.assertRaises(HTTPError) as cm:
             call_api(
@@ -420,14 +420,14 @@ class TestLP1074374(unittest.TestCase):
             self.mlist.subscribe(address)
         call_api('http://localhost:9001/3.0/users/anne@example.com',
                  method='DELETE')
-        content, response = call_api('http://localhost:9001/3.0/addresses')
+        json, response = call_api('http://localhost:9001/3.0/addresses')
         # There are no addresses, and thus no entries in the returned JSON.
-        self.assertNotIn('entries', content)
-        self.assertEqual(content['total_size'], 0)
+        self.assertNotIn('entries', json)
+        self.assertEqual(json['total_size'], 0)
         # There are also no members.
-        content, response = call_api('http://localhost:9001/3.0/members')
-        self.assertNotIn('entries', content)
-        self.assertEqual(content['total_size'], 0)
+        json, response = call_api('http://localhost:9001/3.0/members')
+        self.assertNotIn('entries', json)
+        self.assertEqual(json['total_size'], 0)
         # Now we can create a new user record for Anne, and subscribe her to
         # the mailing list, this time all through the API.
         call_api('http://localhost:9001/3.0/users', dict(
@@ -440,17 +440,17 @@ class TestLP1074374(unittest.TestCase):
             pre_verified=True, pre_confirmed=True, pre_approved=True))
         # This is not the Anne you're looking for.  (IOW, the new Anne is a
         # different user).
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com')
-        self.assertNotEqual(user_id, content['user_id'])
+        self.assertNotEqual(user_id, json['user_id'])
         # Anne has an address record.
-        content, response = call_api('http://localhost:9001/3.0/addresses')
-        self.assertEqual(content['total_size'], 1)
-        self.assertEqual(content['entries'][0]['email'], 'anne@example.com')
+        json, response = call_api('http://localhost:9001/3.0/addresses')
+        self.assertEqual(json['total_size'], 1)
+        self.assertEqual(json['entries'][0]['email'], 'anne@example.com')
         # Anne is also a member of the mailing list.
-        content, response = call_api('http://localhost:9001/3.0/members')
-        self.assertEqual(content['total_size'], 1)
-        member = content['entries'][0]
+        json, response = call_api('http://localhost:9001/3.0/members')
+        self.assertEqual(json['total_size'], 1)
+        member = json['entries'][0]
         self.assertEqual(
             member['address'],
             'http://localhost:9001/3.0/addresses/anne@example.com')
@@ -493,10 +493,10 @@ class TestLP1419519(unittest.TestCase):
             'a09@example.com',
             'anne@example.com',
             ])
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.0/users/anne@example.com',
             method='DELETE')
-        self.assertEqual(response.status, 204)
+        self.assertEqual(response.status_code, 204)
         # Now there should be no addresses in the database.
         config.db.abort()
         emails = sorted(address.email for address in self.manager.addresses)
@@ -511,12 +511,12 @@ class TestAPI31Users(unittest.TestCase):
     def test_get_user(self):
         with transaction():
             getUtility(IUserManager).create_user('anne@example.com')
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/users/00000000000000000000000000000001')
         self.assertEqual(
-            content['user_id'], '00000000000000000000000000000001')
+            json['user_id'], '00000000000000000000000000000001')
         self.assertEqual(
-            content['self_link'],
+            json['self_link'],
             'http://localhost:9001/3.1/users/00000000000000000000000000000001')
 
     def test_cannot_get_user_by_int(self):
@@ -531,8 +531,8 @@ class TestAPI31Users(unittest.TestCase):
         with transaction():
             user_manager.create_user('anne@example.com')
             user_manager.create_user('bart@example.com')
-        content, response = call_api('http://localhost:9001/3.1/users')
-        entries = content['entries']
+        json, response = call_api('http://localhost:9001/3.1/users')
+        entries = json['entries']
         self.assertEqual(len(entries), 2)
         self.assertEqual(
             entries[0]['user_id'], '00000000000000000000000000000001')
@@ -546,23 +546,23 @@ class TestAPI31Users(unittest.TestCase):
             'http://localhost:9001/3.1/users/00000000000000000000000000000002')
 
     def test_create_user(self):
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/users', {
                 'email': 'anne@example.com',
                 })
-        self.assertEqual(response.status, 201)
+        self.assertEqual(response.status_code, 201)
         self.assertEqual(
-            response['location'],
+            response.headers['location'],
             'http://localhost:9001/3.1/users/00000000000000000000000000000001')
 
     def test_preferences_self_link(self):
         with transaction():
             user = getUtility(IUserManager).create_user('anne@example.com')
             user.preferences.delivery_mode = DeliveryMode.summary_digests
-        content, response = call_api(
+        json, response = call_api(
             'http://localhost:9001/3.1/users'
             '/00000000000000000000000000000001/preferences')
         self.assertEqual(
-            content['self_link'],
+            json['self_link'],
             'http://localhost:9001/3.1/users'
             '/00000000000000000000000000000001/preferences')