diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 738f7d1920..786c26378d 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -14,16 +14,11 @@ repos:
       - id: check-yaml
         files: .*\.(yaml|yml)$
         args: ['--unsafe']
-  - repo: https://github.com/asottile/pyupgrade
-    rev: v3.17.0
-    hooks:
-      - id: pyupgrade
-        args: ['--py38-plus']
   - repo: https://github.com/astral-sh/ruff-pre-commit
     rev: v0.6.2
     hooks:
       - id: ruff
-        args: ['--fix']
+        args: ['--fix', '--unsafe-fixes']
       - id: ruff-format
   - repo: https://opendev.org/openstack/hacking
     rev: 7.0.0
diff --git a/examples/common.py b/examples/common.py
index d97bfb55cb..650139ec27 100755
--- a/examples/common.py
+++ b/examples/common.py
@@ -241,9 +241,9 @@ def run(opts):
 
     # Do some basic testing here
     sys.stdout.write("Default run command\n")
-    sys.stdout.write("Verbose level: %s\n" % opts.verbose_level)
-    sys.stdout.write("Debug: %s\n" % opts.debug)
-    sys.stdout.write("dump_stack_trace: %s\n" % dump_stack_trace)
+    sys.stdout.write(f"Verbose level: {opts.verbose_level}\n")
+    sys.stdout.write(f"Debug: {opts.debug}\n")
+    sys.stdout.write(f"dump_stack_trace: {dump_stack_trace}\n")
 
 
 def setup():
diff --git a/examples/object_api.py b/examples/object_api.py
index 577fc052fa..4ff245d4ce 100755
--- a/examples/object_api.py
+++ b/examples/object_api.py
@@ -101,7 +101,7 @@ def run(opts):
         o_list = obj_api.object_list(c_list[0]['name'])
         print("\nObject")
         for o in o_list:
-            print("%s" % o)
+            print(f"{o}")
 
 
 if __name__ == "__main__":
diff --git a/examples/osc-lib.py b/examples/osc-lib.py
index cc04bc70fe..6bd0347ac7 100755
--- a/examples/osc-lib.py
+++ b/examples/osc-lib.py
@@ -94,13 +94,13 @@ def run(opts):
         o_list = client_manager.object_store.object_list(c_list[0]['name'])
         print("\nObject")
         for o in o_list:
-            print("%s" % o)
+            print(f"{o}")
 
     # Look at the compute flavors
     flavor_list = client_manager.compute.flavors.list()
     print("\nFlavors:")
     for f in flavor_list:
-        print("%s" % f)
+        print(f"{f}")
 
 
 if __name__ == "__main__":
diff --git a/openstackclient/api/api.py b/openstackclient/api/api.py
index 838383f027..5f78b0ee54 100644
--- a/openstackclient/api/api.py
+++ b/openstackclient/api/api.py
@@ -307,7 +307,7 @@ class BaseAPI(KeystoneSession):
         except ks_exceptions.NotFound:
             kwargs = {attr: value}
             try:
-                ret = self.find_one("/%s/detail" % (path), **kwargs)
+                ret = self.find_one(f"/{path}/detail", **kwargs)
             except ks_exceptions.NotFound:
                 msg = _("%s not found") % value
                 raise exceptions.NotFound(msg)
diff --git a/openstackclient/api/object_store_v1.py b/openstackclient/api/object_store_v1.py
index e7896b1e4f..fd941e4838 100644
--- a/openstackclient/api/object_store_v1.py
+++ b/openstackclient/api/object_store_v1.py
@@ -256,10 +256,7 @@ class APIv1(api.BaseAPI):
         # object's name in the container.
         object_name_str = name if name else object
 
-        full_url = "{}/{}".format(
-            urllib.parse.quote(container),
-            urllib.parse.quote(object_name_str),
-        )
+        full_url = f"{urllib.parse.quote(container)}/{urllib.parse.quote(object_name_str)}"
         with open(object, 'rb') as f:
             response = self.create(
                 full_url,
@@ -293,8 +290,7 @@ class APIv1(api.BaseAPI):
             return
 
         self.delete(
-            "%s/%s"
-            % (urllib.parse.quote(container), urllib.parse.quote(object))
+            f"{urllib.parse.quote(container)}/{urllib.parse.quote(object)}"
         )
 
     def object_list(
@@ -395,8 +391,7 @@ class APIv1(api.BaseAPI):
 
         response = self._request(
             'GET',
-            "%s/%s"
-            % (urllib.parse.quote(container), urllib.parse.quote(object)),
+            f"{urllib.parse.quote(container)}/{urllib.parse.quote(object)}",
             stream=True,
         )
         if response.status_code == 200:
@@ -431,8 +426,7 @@ class APIv1(api.BaseAPI):
         headers = self._set_properties(properties, 'X-Object-Meta-%s')
         if headers:
             self.create(
-                "%s/%s"
-                % (urllib.parse.quote(container), urllib.parse.quote(object)),
+                f"{urllib.parse.quote(container)}/{urllib.parse.quote(object)}",
                 headers=headers,
             )
 
@@ -455,8 +449,7 @@ class APIv1(api.BaseAPI):
         headers = self._unset_properties(properties, 'X-Remove-Object-Meta-%s')
         if headers:
             self.create(
-                "%s/%s"
-                % (urllib.parse.quote(container), urllib.parse.quote(object)),
+                f"{urllib.parse.quote(container)}/{urllib.parse.quote(object)}",
                 headers=headers,
             )
 
@@ -480,8 +473,7 @@ class APIv1(api.BaseAPI):
 
         response = self._request(
             'HEAD',
-            "%s/%s"
-            % (urllib.parse.quote(container), urllib.parse.quote(object)),
+            f"{urllib.parse.quote(container)}/{urllib.parse.quote(object)}",
         )
 
         data = {
diff --git a/openstackclient/common/quota.py b/openstackclient/common/quota.py
index b3b04e0b3b..4356cae66f 100644
--- a/openstackclient/common/quota.py
+++ b/openstackclient/common/quota.py
@@ -507,8 +507,8 @@ class SetQuota(common.NetDetectionMixin, command.Command):
         )
         for k, v, h in self._build_options_list():
             parser.add_argument(
-                '--%s' % v,
-                metavar='<%s>' % v,
+                f'--{v}',
+                metavar=f'<{v}>',
                 dest=k,
                 type=int,
                 help=h,
@@ -590,7 +590,7 @@ class SetQuota(common.NetDetectionMixin, command.Command):
                         parsed_args.volume_type
                         and k in IMPACT_VOLUME_TYPE_QUOTAS
                     ):
-                        k = k + '_%s' % parsed_args.volume_type
+                        k = k + f'_{parsed_args.volume_type}'
                     volume_kwargs[k] = value
 
         if self.app.client_manager.is_network_endpoint_enabled():
diff --git a/openstackclient/compute/v2/server.py b/openstackclient/compute/v2/server.py
index 293e010a72..9cf200f15e 100644
--- a/openstackclient/compute/v2/server.py
+++ b/openstackclient/compute/v2/server.py
@@ -1504,7 +1504,7 @@ class CreateServer(command.ShowOne):
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
@@ -2189,7 +2189,7 @@ class DeleteServer(command.Command):
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
@@ -3198,7 +3198,7 @@ revert to release the new server and restart the old one."""
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
@@ -3350,7 +3350,7 @@ class RebootServer(command.Command):
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
@@ -3555,7 +3555,7 @@ class RebuildServer(command.ShowOne):
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
@@ -3816,7 +3816,7 @@ host."""
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
@@ -4188,7 +4188,7 @@ release the new server and restart the old one."""
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
@@ -4584,7 +4584,7 @@ class ShelveServer(command.Command):
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
@@ -5181,7 +5181,7 @@ class UnshelveServer(command.Command):
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
diff --git a/openstackclient/compute/v2/server_backup.py b/openstackclient/compute/v2/server_backup.py
index 59bd5540e8..96b325b104 100644
--- a/openstackclient/compute/v2/server_backup.py
+++ b/openstackclient/compute/v2/server_backup.py
@@ -68,7 +68,7 @@ class CreateServerBackup(command.ShowOne):
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stderr.write('\rProgress: %s' % progress)
+                self.app.stderr.write(f'\rProgress: {progress}')
                 self.app.stderr.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
diff --git a/openstackclient/compute/v2/server_image.py b/openstackclient/compute/v2/server_image.py
index 12b45b2854..e49a5d36cd 100644
--- a/openstackclient/compute/v2/server_image.py
+++ b/openstackclient/compute/v2/server_image.py
@@ -69,7 +69,7 @@ class CreateServerImage(command.ShowOne):
     def take_action(self, parsed_args):
         def _show_progress(progress):
             if progress:
-                self.app.stdout.write('\rProgress: %s' % progress)
+                self.app.stdout.write(f'\rProgress: {progress}')
                 self.app.stdout.flush()
 
         compute_client = self.app.client_manager.sdk_connection.compute
diff --git a/openstackclient/compute/v2/usage.py b/openstackclient/compute/v2/usage.py
index 2b3fa6a3f8..27f9335bb5 100644
--- a/openstackclient/compute/v2/usage.py
+++ b/openstackclient/compute/v2/usage.py
@@ -60,7 +60,7 @@ class CountColumn(cliff_columns.FormattableColumn):
 
 class FloatColumn(cliff_columns.FormattableColumn):
     def human_readable(self):
-        return float("%.2f" % self._value)
+        return float(f"{self._value:.2f}")
 
 
 def _formatters(project_cache):
diff --git a/openstackclient/identity/common.py b/openstackclient/identity/common.py
index 4e5f083de2..50ad2fed67 100644
--- a/openstackclient/identity/common.py
+++ b/openstackclient/identity/common.py
@@ -34,7 +34,7 @@ def find_service_in_list(service_list, service_id):
         if service.id == service_id:
             return service
     raise exceptions.CommandError(
-        "No service with a type, name or ID of '%s' exists." % service_id
+        f"No service with a type, name or ID of '{service_id}' exists."
     )
 
 
diff --git a/openstackclient/image/v2/image.py b/openstackclient/image/v2/image.py
index 5390a704ca..094c507b0d 100644
--- a/openstackclient/image/v2/image.py
+++ b/openstackclient/image/v2/image.py
@@ -421,8 +421,8 @@ class CreateImage(command.ShowOne):
         identity_common.add_project_domain_option_to_parser(parser)
         for deadopt in self.deadopts:
             parser.add_argument(
-                "--%s" % deadopt,
-                metavar="<%s>" % deadopt,
+                f"--{deadopt}",
+                metavar=f"<{deadopt}>",
                 dest=deadopt.replace('-', '_'),
                 help=argparse.SUPPRESS,
             )
@@ -488,7 +488,7 @@ class CreateImage(command.ShowOne):
                 fp = open(parsed_args.filename, 'rb')
             except FileNotFoundError:
                 raise exceptions.CommandError(
-                    '%r is not a valid file' % parsed_args.filename,
+                    f'{parsed_args.filename!r} is not a valid file',
                 )
         else:
             fp = get_data_from_stdin()
@@ -1209,8 +1209,8 @@ class SetImage(command.Command):
         identity_common.add_project_domain_option_to_parser(parser)
         for deadopt in self.deadopts:
             parser.add_argument(
-                "--%s" % deadopt,
-                metavar="<%s>" % deadopt,
+                f"--{deadopt}",
+                metavar=f"<{deadopt}>",
                 dest=f"dead_{deadopt.replace('-', '_')}",
                 help=argparse.SUPPRESS,
             )
@@ -1575,7 +1575,7 @@ class StageImage(command.Command):
                 fp = open(parsed_args.filename, 'rb')
             except FileNotFoundError:
                 raise exceptions.CommandError(
-                    '%r is not a valid file' % parsed_args.filename,
+                    f'{parsed_args.filename!r} is not a valid file',
                 )
         else:
             fp = get_data_from_stdin()
diff --git a/openstackclient/network/common.py b/openstackclient/network/common.py
index 4c01f90ef4..3d5237b1b1 100644
--- a/openstackclient/network/common.py
+++ b/openstackclient/network/common.py
@@ -120,13 +120,14 @@ class NetDetectionMixin(metaclass=abc.ABCMeta):
     @staticmethod
     def split_help(network_help, compute_help):
         return (
-            "*%(network_qualifier)s:*\n  %(network_help)s\n\n"
-            "*%(compute_qualifier)s:*\n  %(compute_help)s"
-            % dict(
-                network_qualifier=_("Network version 2"),
-                network_help=network_help,
-                compute_qualifier=_("Compute version 2"),
-                compute_help=compute_help,
+            "*{network_qualifier}:*\n  {network_help}\n\n"
+            "*{compute_qualifier}:*\n  {compute_help}".format(
+                **dict(
+                    network_qualifier=_("Network version 2"),
+                    network_help=network_help,
+                    compute_qualifier=_("Compute version 2"),
+                    compute_help=compute_help,
+                )
             )
         )
 
diff --git a/openstackclient/network/v2/network_agent.py b/openstackclient/network/v2/network_agent.py
index d31bd3f561..bccde7ef3a 100644
--- a/openstackclient/network/v2/network_agent.py
+++ b/openstackclient/network/v2/network_agent.py
@@ -89,9 +89,7 @@ class AddNetworkToAgent(command.Command):
             try:
                 client.add_dhcp_agent_to_network(agent, network)
             except Exception:
-                msg = 'Failed to add {} to {}'.format(
-                    network.name, agent.agent_type
-                )
+                msg = f'Failed to add {network.name} to {agent.agent_type}'
                 exceptions.CommandError(msg)
 
 
@@ -321,9 +319,7 @@ class RemoveNetworkFromAgent(command.Command):
             try:
                 client.remove_dhcp_agent_from_network(agent, network)
             except Exception:
-                msg = 'Failed to remove {} to {}'.format(
-                    network.name, agent.agent_type
-                )
+                msg = f'Failed to remove {network.name} to {agent.agent_type}'
                 exceptions.CommandError(msg)
 
 
diff --git a/openstackclient/network/v2/network_qos_rule.py b/openstackclient/network/v2/network_qos_rule.py
index 70f4d28432..0b5e06fe5b 100644
--- a/openstackclient/network/v2/network_qos_rule.py
+++ b/openstackclient/network/v2/network_qos_rule.py
@@ -159,10 +159,7 @@ def _get_item_properties(item, fields):
 
 def _rule_action_call(client, action, rule_type):
     rule_type = rule_type.replace('-', '_')
-    func_name = '{action}_qos_{rule_type}_rule'.format(
-        action=action,
-        rule_type=rule_type,
-    )
+    func_name = f'{action}_qos_{rule_type}_rule'
     return getattr(client, func_name)
 
 
@@ -311,7 +308,7 @@ class DeleteNetworkQosRule(command.Command):
             )
             rule_type = _find_rule_type(qos, rule_id)
             if not rule_type:
-                raise Exception('Rule %s not found' % rule_id)
+                raise Exception(f'Rule {rule_id} not found')
             _rule_action_call(network_client, ACTION_DELETE, rule_type)(
                 rule_id, qos.id
             )
diff --git a/openstackclient/network/v2/port.py b/openstackclient/network/v2/port.py
index b1e60df4e8..84aef47757 100644
--- a/openstackclient/network/v2/port.py
+++ b/openstackclient/network/v2/port.py
@@ -274,13 +274,13 @@ def _prepare_filter_fixed_ips(client_manager, parsed_args):
                 _subnet = client.find_subnet(
                     subnet_name_id, ignore_missing=False
                 )
-                ips.append('subnet_id=%s' % _subnet.id)
+                ips.append(f'subnet_id={_subnet.id}')
 
         if 'ip-address' in ip_spec:
-            ips.append('ip_address=%s' % ip_spec['ip-address'])
+            ips.append('ip_address={}'.format(ip_spec['ip-address']))
 
         if 'ip-substring' in ip_spec:
-            ips.append('ip_address_substr=%s' % ip_spec['ip-substring'])
+            ips.append('ip_address_substr={}'.format(ip_spec['ip-substring']))
     return ips
 
 
diff --git a/openstackclient/shell.py b/openstackclient/shell.py
index 5c64cb7cb1..df60d3c073 100644
--- a/openstackclient/shell.py
+++ b/openstackclient/shell.py
@@ -96,8 +96,9 @@ class OpenStackShell(shell.OpenStackShell):
                             key=lambda s: list(map(int, s.split('.'))),
                         )
                         self.log.warning(
-                            "%s version %s is not in supported versions: %s"
-                            % (api, version_opt, ', '.join(sorted_versions))
+                            "{} version {} is not in supported versions: {}".format(
+                                api, version_opt, ', '.join(sorted_versions)
+                            )
                         )
 
                 # Command groups deal only with major versions
diff --git a/openstackclient/tests/functional/common/test_help.py b/openstackclient/tests/functional/common/test_help.py
index f1aea8ee98..4ff365b6da 100644
--- a/openstackclient/tests/functional/common/test_help.py
+++ b/openstackclient/tests/functional/common/test_help.py
@@ -60,15 +60,9 @@ class HelpTests(base.TestCase):
         """Check server commands in main help message."""
         raw_output = self.openstack('help')
         for command, description in self.SERVER_COMMANDS:
-            msg = 'Command: {} not found in help output:\n{}'.format(
-                command,
-                raw_output,
-            )
+            msg = f'Command: {command} not found in help output:\n{raw_output}'
             self.assertIn(command, raw_output, msg)
-            msg = 'Description: {} not found in help output:\n{}'.format(
-                description,
-                raw_output,
-            )
+            msg = f'Description: {description} not found in help output:\n{raw_output}'
             self.assertIn(description, raw_output, msg)
 
     def test_server_only_help(self):
diff --git a/openstackclient/tests/functional/common/test_module.py b/openstackclient/tests/functional/common/test_module.py
index 1506683499..41486d1ff5 100644
--- a/openstackclient/tests/functional/common/test_module.py
+++ b/openstackclient/tests/functional/common/test_module.py
@@ -59,7 +59,7 @@ class CommandTest(base.TestCase):
         input_groups = ['volume', 'network', 'image', 'identity', 'compute.v2']
         for each_input in input_groups:
             cmd_output = self.openstack(
-                'command list --group %s' % each_input,
+                f'command list --group {each_input}',
                 parse_output=True,
             )
             group_names = [each.get('Command Group') for each in cmd_output]
diff --git a/openstackclient/tests/functional/common/test_quota.py b/openstackclient/tests/functional/common/test_quota.py
index 8aa93a9294..677db50367 100644
--- a/openstackclient/tests/functional/common/test_quota.py
+++ b/openstackclient/tests/functional/common/test_quota.py
@@ -165,8 +165,7 @@ class QuotaTests(base.TestCase):
         # That will ensure we have at least two networks in the system.
         for _ in range(2):
             self.openstack(
-                'network create --project %s %s'
-                % (self.PROJECT_NAME, uuid.uuid4().hex)
+                f'network create --project {self.PROJECT_NAME} {uuid.uuid4().hex}'
             )
 
         self.assertRaises(
@@ -211,8 +210,7 @@ class QuotaTests(base.TestCase):
         # That will ensure we have at least two networks in the system.
         for _ in range(2):
             self.openstack(
-                'network create --project %s %s'
-                % (self.PROJECT_NAME, uuid.uuid4().hex)
+                f'network create --project {self.PROJECT_NAME} {uuid.uuid4().hex}'
             )
 
         self.openstack('quota set --networks 1 --force ' + self.PROJECT_NAME)
diff --git a/openstackclient/tests/functional/compute/v2/common.py b/openstackclient/tests/functional/compute/v2/common.py
index ef59d458a1..4ada4304cb 100644
--- a/openstackclient/tests/functional/compute/v2/common.py
+++ b/openstackclient/tests/functional/compute/v2/common.py
@@ -132,9 +132,7 @@ class ComputeTestCase(base.TestCase):
                 print(f'Server {name} now has status {status}')
                 break
             print(
-                'Server {}: Waiting for {}, current status: {}'.format(
-                    name, expected_status, status
-                )
+                f'Server {name}: Waiting for {expected_status}, current status: {status}'
             )
             self.assertNotIn(status, failures)
             time.sleep(interval)
diff --git a/openstackclient/tests/functional/compute/v2/test_hypervisor.py b/openstackclient/tests/functional/compute/v2/test_hypervisor.py
index 7e90b743cb..0ed4e904bc 100644
--- a/openstackclient/tests/functional/compute/v2/test_hypervisor.py
+++ b/openstackclient/tests/functional/compute/v2/test_hypervisor.py
@@ -37,8 +37,8 @@ class HypervisorTests(base.TestCase):
         for i in ids1:
             cmd_output = json.loads(
                 self.openstack(
-                    "hypervisor show %s -f json "
-                    " --os-compute-api-version 2.1" % (i)
+                    f"hypervisor show {i} -f json "
+                    " --os-compute-api-version 2.1"
                 )
             )
             self.assertIsNotNone(cmd_output)
@@ -47,6 +47,6 @@ class HypervisorTests(base.TestCase):
         # Show test - latest microversion
         for i in ids2:
             cmd_output = json.loads(
-                self.openstack("hypervisor show %s -f json" % (i))
+                self.openstack(f"hypervisor show {i} -f json")
             )
             self.assertIsNotNone(cmd_output)
diff --git a/openstackclient/tests/functional/compute/v2/test_keypair.py b/openstackclient/tests/functional/compute/v2/test_keypair.py
index ebc78abdae..4b178cb723 100644
--- a/openstackclient/tests/functional/compute/v2/test_keypair.py
+++ b/openstackclient/tests/functional/compute/v2/test_keypair.py
@@ -96,7 +96,7 @@ class KeypairTests(KeypairBase):
             f.flush()
 
             raw_output = self.openstack(
-                'keypair create --public-key %s tmpkey' % f.name,
+                f'keypair create --public-key {f.name} tmpkey',
             )
             self.addCleanup(
                 self.openstack,
@@ -113,7 +113,7 @@ class KeypairTests(KeypairBase):
         """
         with tempfile.NamedTemporaryFile(mode='w+') as f:
             cmd_output = self.openstack(
-                'keypair create --private-key %s tmpkey' % f.name,
+                f'keypair create --private-key {f.name} tmpkey',
                 parse_output=True,
             )
             self.addCleanup(self.openstack, 'keypair delete tmpkey')
diff --git a/openstackclient/tests/functional/compute/v2/test_server.py b/openstackclient/tests/functional/compute/v2/test_server.py
index d6638d2f71..19531da47a 100644
--- a/openstackclient/tests/functional/compute/v2/test_server.py
+++ b/openstackclient/tests/functional/compute/v2/test_server.py
@@ -111,7 +111,7 @@ class ServerTests(common.ComputeTestCase):
             )
         except exceptions.CommandFailed as e:
             self.assertIn(
-                'marker [%s] not found' % (name2), e.stderr.decode('utf-8')
+                f'marker [{name2}] not found', e.stderr.decode('utf-8')
             )
 
     def test_server_list_with_changes_before(self):
diff --git a/openstackclient/tests/functional/identity/v2/common.py b/openstackclient/tests/functional/identity/v2/common.py
index a78f3b0315..dd2e271933 100644
--- a/openstackclient/tests/functional/identity/v2/common.py
+++ b/openstackclient/tests/functional/identity/v2/common.py
@@ -67,13 +67,9 @@ class IdentityTests(base.TestCase):
             cls.openstack(
                 '--os-identity-api-version 2 '
                 'project create '
-                '--description %(description)s '
+                f'--description {cls.project_description} '
                 '--enable '
-                '%(name)s'
-                % {
-                    'description': cls.project_description,
-                    'name': cls.project_name,
-                }
+                f'{cls.project_name}'
             )
         except tempest_exceptions.CommandFailed:
             # Good chance this is due to Identity v2 admin not being enabled
@@ -87,7 +83,7 @@ class IdentityTests(base.TestCase):
         try:
             cls.openstack(
                 '--os-identity-api-version 2 '
-                'project delete %s' % cls.project_name
+                f'project delete {cls.project_name}'
             )
         finally:
             super().tearDownClass()
@@ -111,14 +107,13 @@ class IdentityTests(base.TestCase):
         project_description = data_utils.rand_name('description')
         raw_output = self.openstack(
             'project create '
-            '--description %(description)s '
-            '--enable %(name)s'
-            % {'description': project_description, 'name': project_name}
+            f'--description {project_description} '
+            f'--enable {project_name}'
         )
         project = self.parse_show_as_object(raw_output)
         if add_clean_up:
             self.addCleanup(
-                self.openstack, 'project delete %s' % project['id']
+                self.openstack, 'project delete {}'.format(project['id'])
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.PROJECT_FIELDS)
@@ -130,22 +125,18 @@ class IdentityTests(base.TestCase):
         email = data_utils.rand_name() + '@example.com'
         raw_output = self.openstack(
             'user create '
-            '--project %(project)s '
-            '--password %(password)s '
-            '--email %(email)s '
+            f'--project {self.project_name} '
+            f'--password {password} '
+            f'--email {email} '
             '--enable '
-            '%(name)s'
-            % {
-                'project': self.project_name,
-                'email': email,
-                'password': password,
-                'name': username,
-            }
+            f'{username}'
         )
         if add_clean_up:
             self.addCleanup(
                 self.openstack,
-                'user delete %s' % self.parse_show_as_object(raw_output)['id'],
+                'user delete {}'.format(
+                    self.parse_show_as_object(raw_output)['id']
+                ),
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.USER_FIELDS)
@@ -153,10 +144,12 @@ class IdentityTests(base.TestCase):
 
     def _create_dummy_role(self, add_clean_up=True):
         role_name = data_utils.rand_name('TestRole')
-        raw_output = self.openstack('role create %s' % role_name)
+        raw_output = self.openstack(f'role create {role_name}')
         role = self.parse_show_as_object(raw_output)
         if add_clean_up:
-            self.addCleanup(self.openstack, 'role delete %s' % role['id'])
+            self.addCleanup(
+                self.openstack, 'role delete {}'.format(role['id'])
+            )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ROLE_FIELDS)
         self.assertEqual(role_name, role['name'])
@@ -168,7 +161,7 @@ class IdentityTests(base.TestCase):
         access_key = ec2_credentials['access']
         if add_clean_up:
             self.addCleanup(
-                self.openstack, 'ec2 credentials delete %s' % access_key
+                self.openstack, f'ec2 credentials delete {access_key}'
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.EC2_CREDENTIALS_FIELDS)
@@ -178,7 +171,9 @@ class IdentityTests(base.TestCase):
         raw_output = self.openstack('token issue')
         token = self.parse_show_as_object(raw_output)
         if add_clean_up:
-            self.addCleanup(self.openstack, 'token revoke %s' % token['id'])
+            self.addCleanup(
+                self.openstack, 'token revoke {}'.format(token['id'])
+            )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.TOKEN_FIELDS)
         return token['id']
@@ -189,19 +184,14 @@ class IdentityTests(base.TestCase):
         type_name = data_utils.rand_name('TestType')
         raw_output = self.openstack(
             'service create '
-            '--name %(name)s '
-            '--description %(description)s '
-            '%(type)s'
-            % {
-                'name': service_name,
-                'description': description,
-                'type': type_name,
-            }
+            f'--name {service_name} '
+            f'--description {description} '
+            f'{type_name}'
         )
         if add_clean_up:
             service = self.parse_show_as_object(raw_output)
             self.addCleanup(
-                self.openstack, 'service delete %s' % service['id']
+                self.openstack, 'service delete {}'.format(service['id'])
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.SERVICE_FIELDS)
@@ -215,23 +205,16 @@ class IdentityTests(base.TestCase):
         internal_url = data_utils.rand_url()
         raw_output = self.openstack(
             'endpoint create '
-            '--publicurl %(publicurl)s '
-            '--adminurl %(adminurl)s '
-            '--internalurl %(internalurl)s '
-            '--region %(region)s '
-            '%(service)s'
-            % {
-                'publicurl': public_url,
-                'adminurl': admin_url,
-                'internalurl': internal_url,
-                'region': region_id,
-                'service': service_name,
-            }
+            f'--publicurl {public_url} '
+            f'--adminurl {admin_url} '
+            f'--internalurl {internal_url} '
+            f'--region {region_id} '
+            f'{service_name}'
         )
         endpoint = self.parse_show_as_object(raw_output)
         if add_clean_up:
             self.addCleanup(
-                self.openstack, 'endpoint delete %s' % endpoint['id']
+                self.openstack, 'endpoint delete {}'.format(endpoint['id'])
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ENDPOINT_FIELDS)
diff --git a/openstackclient/tests/functional/identity/v2/test_catalog.py b/openstackclient/tests/functional/identity/v2/test_catalog.py
index 1cef314f74..67c6c36945 100644
--- a/openstackclient/tests/functional/identity/v2/test_catalog.py
+++ b/openstackclient/tests/functional/identity/v2/test_catalog.py
@@ -35,7 +35,7 @@ class CatalogTests(common.IdentityTests):
         | type      | identity                                  |
         +-----------+-------------------------------------------+
         """
-        raw_output = self.openstack('catalog show %s' % 'identity')
+        raw_output = self.openstack('catalog show {}'.format('identity'))
         items = self.parse_show(raw_output)
         # items may have multiple endpoint urls with empty key
         self.assert_show_fields(items, ['endpoints', 'name', 'type', ''])
diff --git a/openstackclient/tests/functional/identity/v2/test_ec2_credentials.py b/openstackclient/tests/functional/identity/v2/test_ec2_credentials.py
index 6d25bdae2b..b72dc40145 100644
--- a/openstackclient/tests/functional/identity/v2/test_ec2_credentials.py
+++ b/openstackclient/tests/functional/identity/v2/test_ec2_credentials.py
@@ -20,7 +20,7 @@ class EC2CredentialsTests(common.IdentityTests):
     def test_ec2_credentials_delete(self):
         access_key = self._create_dummy_ec2_credentials(add_clean_up=False)
         raw_output = self.openstack(
-            'ec2 credentials delete %s' % access_key,
+            f'ec2 credentials delete {access_key}',
         )
         self.assertEqual(0, len(raw_output))
 
@@ -41,7 +41,7 @@ class EC2CredentialsTests(common.IdentityTests):
     def test_ec2_credentials_show(self):
         access_key = self._create_dummy_ec2_credentials()
         show_output = self.openstack(
-            'ec2 credentials show %s' % access_key,
+            f'ec2 credentials show {access_key}',
         )
         items = self.parse_show(show_output)
         self.assert_show_fields(items, self.EC2_CREDENTIALS_FIELDS)
diff --git a/openstackclient/tests/functional/identity/v2/test_endpoint.py b/openstackclient/tests/functional/identity/v2/test_endpoint.py
index bafbfdaed9..8a0077b7f2 100644
--- a/openstackclient/tests/functional/identity/v2/test_endpoint.py
+++ b/openstackclient/tests/functional/identity/v2/test_endpoint.py
@@ -19,7 +19,7 @@ class EndpointTests(common.IdentityTests):
 
     def test_endpoint_delete(self):
         endpoint_id = self._create_dummy_endpoint(add_clean_up=False)
-        raw_output = self.openstack('endpoint delete %s' % endpoint_id)
+        raw_output = self.openstack(f'endpoint delete {endpoint_id}')
         self.assertEqual(0, len(raw_output))
 
     def test_endpoint_multi_delete(self):
@@ -39,6 +39,6 @@ class EndpointTests(common.IdentityTests):
 
     def test_endpoint_show(self):
         endpoint_id = self._create_dummy_endpoint()
-        raw_output = self.openstack('endpoint show %s' % endpoint_id)
+        raw_output = self.openstack(f'endpoint show {endpoint_id}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ENDPOINT_FIELDS)
diff --git a/openstackclient/tests/functional/identity/v2/test_project.py b/openstackclient/tests/functional/identity/v2/test_project.py
index 1ad0edaa31..2dfc95edb8 100644
--- a/openstackclient/tests/functional/identity/v2/test_project.py
+++ b/openstackclient/tests/functional/identity/v2/test_project.py
@@ -21,13 +21,13 @@ class ProjectTests(common.IdentityTests):
         description = data_utils.rand_name('description')
         raw_output = self.openstack(
             'project create '
-            '--description %(description)s '
+            f'--description {description} '
             '--enable '
             '--property k1=v1 '
             '--property k2=v2 '
-            '%(name)s' % {'description': description, 'name': project_name}
+            f'{project_name}'
         )
-        self.addCleanup(self.openstack, 'project delete %s' % project_name)
+        self.addCleanup(self.openstack, f'project delete {project_name}')
         items = self.parse_show(raw_output)
         show_fields = list(self.PROJECT_FIELDS)
         show_fields.extend(['k1', 'k2'])
@@ -38,7 +38,7 @@ class ProjectTests(common.IdentityTests):
 
     def test_project_delete(self):
         project_name = self._create_dummy_project(add_clean_up=False)
-        raw_output = self.openstack('project delete %s' % project_name)
+        raw_output = self.openstack(f'project delete {project_name}')
         self.assertEqual(0, len(raw_output))
 
     def test_project_list(self):
@@ -51,14 +51,14 @@ class ProjectTests(common.IdentityTests):
         new_project_name = data_utils.rand_name('NewTestProject')
         raw_output = self.openstack(
             'project set '
-            '--name %(new_name)s '
+            f'--name {new_project_name} '
             '--disable '
             '--property k0=v0 '
-            '%(name)s' % {'new_name': new_project_name, 'name': project_name}
+            f'{project_name}'
         )
         self.assertEqual(0, len(raw_output))
         # check project details
-        raw_output = self.openstack('project show %s' % new_project_name)
+        raw_output = self.openstack(f'project show {new_project_name}')
         items = self.parse_show(raw_output)
         fields = list(self.PROJECT_FIELDS)
         fields.extend(['properties'])
@@ -70,7 +70,7 @@ class ProjectTests(common.IdentityTests):
 
     def test_project_show(self):
         project_name = self._create_dummy_project()
-        raw_output = self.openstack('project show %s' % project_name)
+        raw_output = self.openstack(f'project show {project_name}')
         items = self.parse_show(raw_output)
         fields = list(self.PROJECT_FIELDS)
         fields.extend(['properties'])
diff --git a/openstackclient/tests/functional/identity/v2/test_role.py b/openstackclient/tests/functional/identity/v2/test_role.py
index fb22f0181e..ec6134012f 100644
--- a/openstackclient/tests/functional/identity/v2/test_role.py
+++ b/openstackclient/tests/functional/identity/v2/test_role.py
@@ -19,7 +19,7 @@ class RoleTests(common.IdentityTests):
 
     def test_role_delete(self):
         role_name = self._create_dummy_role(add_clean_up=False)
-        raw_output = self.openstack('role delete %s' % role_name)
+        raw_output = self.openstack(f'role delete {role_name}')
         self.assertEqual(0, len(raw_output))
 
     def test_role_list(self):
@@ -30,7 +30,7 @@ class RoleTests(common.IdentityTests):
 
     def test_role_show(self):
         role_name = self._create_dummy_role()
-        raw_output = self.openstack('role show %s' % role_name)
+        raw_output = self.openstack(f'role show {role_name}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ROLE_FIELDS)
 
@@ -39,26 +39,16 @@ class RoleTests(common.IdentityTests):
         username = self._create_dummy_user()
         raw_output = self.openstack(
             'role add '
-            '--project %(project)s '
-            '--user %(user)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'user': username,
-                'role': role_name,
-            }
+            f'--project {self.project_name} '
+            f'--user {username} '
+            f'{role_name}'
         )
         self.addCleanup(
             self.openstack,
             'role remove '
-            '--project %(project)s '
-            '--user %(user)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'user': username,
-                'role': role_name,
-            },
+            f'--project {self.project_name} '
+            f'--user {username} '
+            f'{role_name}',
         )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ROLE_FIELDS)
@@ -68,25 +58,15 @@ class RoleTests(common.IdentityTests):
         username = self._create_dummy_user()
         add_raw_output = self.openstack(
             'role add '
-            '--project %(project)s '
-            '--user %(user)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'user': username,
-                'role': role_name,
-            }
+            f'--project {self.project_name} '
+            f'--user {username} '
+            f'{role_name}'
         )
         del_raw_output = self.openstack(
             'role remove '
-            '--project %(project)s '
-            '--user %(user)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'user': username,
-                'role': role_name,
-            }
+            f'--project {self.project_name} '
+            f'--user {username} '
+            f'{role_name}'
         )
         items = self.parse_show(add_raw_output)
         self.assert_show_fields(items, self.ROLE_FIELDS)
diff --git a/openstackclient/tests/functional/identity/v2/test_service.py b/openstackclient/tests/functional/identity/v2/test_service.py
index 7afa967d4b..5f1611cafd 100644
--- a/openstackclient/tests/functional/identity/v2/test_service.py
+++ b/openstackclient/tests/functional/identity/v2/test_service.py
@@ -19,7 +19,7 @@ class ServiceTests(common.IdentityTests):
 
     def test_service_delete(self):
         service_name = self._create_dummy_service(add_clean_up=False)
-        raw_output = self.openstack('service delete %s' % service_name)
+        raw_output = self.openstack(f'service delete {service_name}')
         self.assertEqual(0, len(raw_output))
 
     def test_service_multi_delete(self):
@@ -38,6 +38,6 @@ class ServiceTests(common.IdentityTests):
 
     def test_service_show(self):
         service_name = self._create_dummy_service()
-        raw_output = self.openstack('service show %s' % service_name)
+        raw_output = self.openstack(f'service show {service_name}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.SERVICE_FIELDS)
diff --git a/openstackclient/tests/functional/identity/v2/test_token.py b/openstackclient/tests/functional/identity/v2/test_token.py
index d2ef78e385..51be24319a 100644
--- a/openstackclient/tests/functional/identity/v2/test_token.py
+++ b/openstackclient/tests/functional/identity/v2/test_token.py
@@ -19,5 +19,5 @@ class TokenTests(common.IdentityTests):
 
     def test_token_revoke(self):
         token_id = self._create_dummy_token(add_clean_up=False)
-        raw_output = self.openstack('token revoke %s' % token_id)
+        raw_output = self.openstack(f'token revoke {token_id}')
         self.assertEqual(0, len(raw_output))
diff --git a/openstackclient/tests/functional/identity/v2/test_user.py b/openstackclient/tests/functional/identity/v2/test_user.py
index d30e3c4567..e0d2c956a7 100644
--- a/openstackclient/tests/functional/identity/v2/test_user.py
+++ b/openstackclient/tests/functional/identity/v2/test_user.py
@@ -22,7 +22,7 @@ class UserTests(common.IdentityTests):
 
     def test_user_delete(self):
         username = self._create_dummy_user(add_clean_up=False)
-        raw_output = self.openstack('user delete %s' % username)
+        raw_output = self.openstack(f'user delete {username}')
         self.assertEqual(0, len(raw_output))
 
     def test_user_list(self):
@@ -32,26 +32,24 @@ class UserTests(common.IdentityTests):
 
     def test_user_set(self):
         username = self._create_dummy_user()
-        raw_output = self.openstack('user show %s' % username)
+        raw_output = self.openstack(f'user show {username}')
         user = self.parse_show_as_object(raw_output)
         new_username = data_utils.rand_name('NewTestUser')
         new_email = data_utils.rand_name() + '@example.com'
         raw_output = self.openstack(
-            'user set '
-            '--email %(email)s '
-            '--name %(new_name)s '
-            '%(id)s'
-            % {'email': new_email, 'new_name': new_username, 'id': user['id']}
+            'user set ' '--email {email} ' '--name {new_name} ' '{id}'.format(
+                email=new_email, new_name=new_username, id=user['id']
+            )
         )
         self.assertEqual(0, len(raw_output))
-        raw_output = self.openstack('user show %s' % new_username)
+        raw_output = self.openstack(f'user show {new_username}')
         new_user = self.parse_show_as_object(raw_output)
         self.assertEqual(user['id'], new_user['id'])
         self.assertEqual(new_email, new_user['email'])
 
     def test_user_show(self):
         username = self._create_dummy_user()
-        raw_output = self.openstack('user show %s' % username)
+        raw_output = self.openstack(f'user show {username}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.USER_FIELDS)
 
diff --git a/openstackclient/tests/functional/identity/v3/common.py b/openstackclient/tests/functional/identity/v3/common.py
index e3c32e35b5..e44f291e5e 100644
--- a/openstackclient/tests/functional/identity/v3/common.py
+++ b/openstackclient/tests/functional/identity/v3/common.py
@@ -156,10 +156,9 @@ class IdentityTests(base.TestCase):
         cls.openstack(
             '--os-identity-api-version 3 '
             'domain create '
-            '--description %(description)s '
+            f'--description {cls.domain_description} '
             '--enable '
-            '%(name)s'
-            % {'description': cls.domain_description, 'name': cls.domain_name}
+            f'{cls.domain_name}'
         )
 
         # create dummy project
@@ -168,15 +167,10 @@ class IdentityTests(base.TestCase):
         cls.openstack(
             '--os-identity-api-version 3 '
             'project create '
-            '--domain %(domain)s '
-            '--description %(description)s '
+            f'--domain {cls.domain_name} '
+            f'--description {cls.project_description} '
             '--enable '
-            '%(name)s'
-            % {
-                'domain': cls.domain_name,
-                'description': cls.project_description,
-                'name': cls.project_name,
-            }
+            f'{cls.project_name}'
         )
 
     @classmethod
@@ -185,16 +179,16 @@ class IdentityTests(base.TestCase):
             # delete dummy project
             cls.openstack(
                 '--os-identity-api-version 3 '
-                'project delete %s' % cls.project_name
+                f'project delete {cls.project_name}'
             )
             # disable and delete dummy domain
             cls.openstack(
                 '--os-identity-api-version 3 '
-                'domain set --disable %s' % cls.domain_name
+                f'domain set --disable {cls.domain_name}'
             )
             cls.openstack(
                 '--os-identity-api-version 3 '
-                'domain delete %s' % cls.domain_name
+                f'domain delete {cls.domain_name}'
             )
         finally:
             super().tearDownClass()
@@ -220,28 +214,21 @@ class IdentityTests(base.TestCase):
         description = data_utils.rand_name('description')
         raw_output = self.openstack(
             'user create '
-            '--domain %(domain)s '
-            '--project %(project)s '
-            '--project-domain %(project_domain)s '
-            '--password %(password)s '
-            '--email %(email)s '
-            '--description %(description)s '
+            f'--domain {self.domain_name} '
+            f'--project {self.project_name} '
+            f'--project-domain {self.domain_name} '
+            f'--password {password} '
+            f'--email {email} '
+            f'--description {description} '
             '--enable '
-            '%(name)s'
-            % {
-                'domain': self.domain_name,
-                'project': self.project_name,
-                'project_domain': self.domain_name,
-                'email': email,
-                'password': password,
-                'description': description,
-                'name': username,
-            }
+            f'{username}'
         )
         if add_clean_up:
             self.addCleanup(
                 self.openstack,
-                'user delete %s' % self.parse_show_as_object(raw_output)['id'],
+                'user delete {}'.format(
+                    self.parse_show_as_object(raw_output)['id']
+                ),
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.USER_FIELDS)
@@ -249,10 +236,12 @@ class IdentityTests(base.TestCase):
 
     def _create_dummy_role(self, add_clean_up=True):
         role_name = data_utils.rand_name('TestRole')
-        raw_output = self.openstack('role create %s' % role_name)
+        raw_output = self.openstack(f'role create {role_name}')
         role = self.parse_show_as_object(raw_output)
         if add_clean_up:
-            self.addCleanup(self.openstack, 'role delete %s' % role['id'])
+            self.addCleanup(
+                self.openstack, 'role delete {}'.format(role['id'])
+            )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ROLE_FIELDS)
         self.assertEqual(role_name, role['name'])
@@ -263,8 +252,8 @@ class IdentityTests(base.TestCase):
         implied_role_name = self._create_dummy_role(add_clean_up)
         self.openstack(
             'implied role create '
-            '--implied-role %(implied_role)s '
-            '%(role)s' % {'implied_role': implied_role_name, 'role': role_name}
+            f'--implied-role {implied_role_name} '
+            f'{role_name}'
         )
 
         return implied_role_name, role_name
@@ -274,21 +263,16 @@ class IdentityTests(base.TestCase):
         description = data_utils.rand_name('description')
         raw_output = self.openstack(
             'group create '
-            '--domain %(domain)s '
-            '--description %(description)s '
-            '%(name)s'
-            % {
-                'domain': self.domain_name,
-                'description': description,
-                'name': group_name,
-            }
+            f'--domain {self.domain_name} '
+            f'--description {description} '
+            f'{group_name}'
         )
         if add_clean_up:
             self.addCleanup(
                 self.openstack,
                 'group delete '
-                '--domain %(domain)s '
-                '%(name)s' % {'domain': self.domain_name, 'name': group_name},
+                f'--domain {self.domain_name} '
+                f'{group_name}',
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.GROUP_FIELDS)
@@ -299,14 +283,13 @@ class IdentityTests(base.TestCase):
         domain_description = data_utils.rand_name('description')
         self.openstack(
             'domain create '
-            '--description %(description)s '
-            '--enable %(name)s'
-            % {'description': domain_description, 'name': domain_name}
+            f'--description {domain_description} '
+            f'--enable {domain_name}'
         )
         if add_clean_up:
-            self.addCleanup(self.openstack, 'domain delete %s' % domain_name)
+            self.addCleanup(self.openstack, f'domain delete {domain_name}')
             self.addCleanup(
-                self.openstack, 'domain set --disable %s' % domain_name
+                self.openstack, f'domain set --disable {domain_name}'
             )
         return domain_name
 
@@ -315,22 +298,16 @@ class IdentityTests(base.TestCase):
         project_description = data_utils.rand_name('description')
         self.openstack(
             'project create '
-            '--domain %(domain)s '
-            '--description %(description)s '
-            '--enable %(name)s'
-            % {
-                'domain': self.domain_name,
-                'description': project_description,
-                'name': project_name,
-            }
+            f'--domain {self.domain_name} '
+            f'--description {project_description} '
+            f'--enable {project_name}'
         )
         if add_clean_up:
             self.addCleanup(
                 self.openstack,
                 'project delete '
-                '--domain %(domain)s '
-                '%(name)s'
-                % {'domain': self.domain_name, 'name': project_name},
+                f'--domain {self.domain_name} '
+                f'{project_name}',
             )
         return project_name
 
@@ -339,20 +316,15 @@ class IdentityTests(base.TestCase):
         description = data_utils.rand_name('description')
         parent_region_arg = ''
         if parent_region is not None:
-            parent_region_arg = '--parent-region %s' % parent_region
+            parent_region_arg = f'--parent-region {parent_region}'
         raw_output = self.openstack(
             'region create '
-            '%(parent_region_arg)s '
-            '--description %(description)s '
-            '%(id)s'
-            % {
-                'parent_region_arg': parent_region_arg,
-                'description': description,
-                'id': region_id,
-            }
+            f'{parent_region_arg} '
+            f'--description {description} '
+            f'{region_id}'
         )
         if add_clean_up:
-            self.addCleanup(self.openstack, 'region delete %s' % region_id)
+            self.addCleanup(self.openstack, f'region delete {region_id}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.REGION_FIELDS)
         return region_id
@@ -363,20 +335,15 @@ class IdentityTests(base.TestCase):
         type_name = data_utils.rand_name('TestType')
         raw_output = self.openstack(
             'service create '
-            '--name %(name)s '
-            '--description %(description)s '
+            f'--name {service_name} '
+            f'--description {description} '
             '--enable '
-            '%(type)s'
-            % {
-                'name': service_name,
-                'description': description,
-                'type': type_name,
-            }
+            f'{type_name}'
         )
         if add_clean_up:
             service = self.parse_show_as_object(raw_output)
             self.addCleanup(
-                self.openstack, 'service delete %s' % service['id']
+                self.openstack, 'service delete {}'.format(service['id'])
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.SERVICE_FIELDS)
@@ -388,22 +355,16 @@ class IdentityTests(base.TestCase):
         endpoint_url = data_utils.rand_url()
         raw_output = self.openstack(
             'endpoint create '
-            '--region %(region)s '
+            f'--region {region_id} '
             '--enable '
-            '%(service)s '
-            '%(interface)s '
-            '%(url)s'
-            % {
-                'region': region_id,
-                'service': service_name,
-                'interface': interface,
-                'url': endpoint_url,
-            }
+            f'{service_name} '
+            f'{interface} '
+            f'{endpoint_url}'
         )
         endpoint = self.parse_show_as_object(raw_output)
         if add_clean_up:
             self.addCleanup(
-                self.openstack, 'endpoint delete %s' % endpoint['id']
+                self.openstack, 'endpoint delete {}'.format(endpoint['id'])
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ENDPOINT_FIELDS)
@@ -414,15 +375,14 @@ class IdentityTests(base.TestCase):
         description = data_utils.rand_name('description')
         raw_output = self.openstack(
             'identity provider create '
-            ' %(name)s '
-            '--description %(description)s '
+            f' {identity_provider} '
+            f'--description {description} '
             '--enable '
-            % {'name': identity_provider, 'description': description}
         )
         if add_clean_up:
             self.addCleanup(
                 self.openstack,
-                'identity provider delete %s' % identity_provider,
+                f'identity provider delete {identity_provider}',
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.IDENTITY_PROVIDER_FIELDS)
@@ -433,16 +393,15 @@ class IdentityTests(base.TestCase):
         description = data_utils.rand_name('description')
         raw_output = self.openstack(
             'service provider create '
-            ' %(name)s '
-            '--description %(description)s '
+            f' {service_provider} '
+            f'--description {description} '
             '--auth-url https://sp.example.com:35357 '
             '--service-provider-url https://sp.example.com:5000 '
             '--enable '
-            % {'name': service_provider, 'description': description}
         )
         if add_clean_up:
             self.addCleanup(
-                self.openstack, 'service provider delete %s' % service_provider
+                self.openstack, f'service provider delete {service_provider}'
             )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.SERVICE_PROVIDER_FIELDS)
@@ -458,9 +417,9 @@ class IdentityTests(base.TestCase):
         }
         raw_output = self.openstack(
             'registered limit create'
-            ' --service %(service_name)s'
-            ' --default-limit %(default_limit)s'
-            ' %(resource_name)s' % params,
+            ' --service {service_name}'
+            ' --default-limit {default_limit}'
+            ' {resource_name}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -469,7 +428,7 @@ class IdentityTests(base.TestCase):
         if add_clean_up:
             self.addCleanup(
                 self.openstack,
-                'registered limit delete %s' % registered_limit_id,
+                f'registered limit delete {registered_limit_id}',
                 cloud=SYSTEM_CLOUD,
             )
 
@@ -486,7 +445,7 @@ class IdentityTests(base.TestCase):
         registered_limit_id = self._create_dummy_registered_limit()
 
         raw_output = self.openstack(
-            'registered limit show %s' % registered_limit_id,
+            f'registered limit show {registered_limit_id}',
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -495,7 +454,7 @@ class IdentityTests(base.TestCase):
         resource_limit = 15
 
         project_name = self._create_dummy_project()
-        raw_output = self.openstack('project show %s' % project_name)
+        raw_output = self.openstack(f'project show {project_name}')
         items = self.parse_show(raw_output)
         project_id = self._extract_value_from_items('id', items)
 
@@ -508,10 +467,10 @@ class IdentityTests(base.TestCase):
 
         raw_output = self.openstack(
             'limit create'
-            ' --project %(project_id)s'
-            ' --service %(service_id)s'
-            ' --resource-limit %(resource_limit)s'
-            ' %(resource_name)s' % params,
+            ' --project {project_id}'
+            ' --service {service_id}'
+            ' --resource-limit {resource_limit}'
+            ' {resource_name}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -520,7 +479,7 @@ class IdentityTests(base.TestCase):
         if add_clean_up:
             self.addCleanup(
                 self.openstack,
-                'limit delete %s' % limit_id,
+                f'limit delete {limit_id}',
                 cloud=SYSTEM_CLOUD,
             )
 
diff --git a/openstackclient/tests/functional/identity/v3/test_application_credential.py b/openstackclient/tests/functional/identity/v3/test_application_credential.py
index 22f2b90bb4..4412592784 100644
--- a/openstackclient/tests/functional/identity/v3/test_application_credential.py
+++ b/openstackclient/tests/functional/identity/v3/test_application_credential.py
@@ -85,34 +85,20 @@ class ApplicationCredentialTests(common.IdentityTests):
         for role in role1, role2:
             self.openstack(
                 'role add'
-                ' --user %(user)s'
-                ' --user-domain %(user_domain)s'
-                ' --project %(project)s'
-                ' --project-domain %(project_domain)s'
-                ' %(role)s'
-                % {
-                    'user': user,
-                    'user_domain': user_domain,
-                    'project': project,
-                    'project_domain': project_domain,
-                    'role': role,
-                }
+                f' --user {user}'
+                f' --user-domain {user_domain}'
+                f' --project {project}'
+                f' --project-domain {project_domain}'
+                f' {role}'
             )
             self.addCleanup(
                 self.openstack,
                 'role remove'
-                ' --user %(user)s'
-                ' --user-domain %(user_domain)s'
-                ' --project %(project)s'
-                ' --project-domain %(project_domain)s'
-                ' %(role)s'
-                % {
-                    'user': user,
-                    'user_domain': user_domain,
-                    'project': project,
-                    'project_domain': project_domain,
-                    'role': role,
-                },
+                f' --user {user}'
+                f' --user-domain {user_domain}'
+                f' --project {project}'
+                f' --project-domain {project_domain}'
+                f' {role}',
             )
         return role1, role2
 
@@ -125,21 +111,13 @@ class ApplicationCredentialTests(common.IdentityTests):
         ).strftime('%Y-%m-%dT%H:%M:%S%z')
         role1, role2 = self._create_role_assignments()
         raw_output = self.openstack(
-            'application credential create %(name)s'
-            ' --secret %(secret)s'
-            ' --description %(description)s'
-            ' --expiration %(tomorrow)s'
-            ' --role %(role1)s'
-            ' --role %(role2)s'
+            f'application credential create {name}'
+            f' --secret {secret}'
+            f' --description {description}'
+            f' --expiration {tomorrow}'
+            f' --role {role1}'
+            f' --role {role2}'
             ' --unrestricted'
-            % {
-                'name': name,
-                'secret': secret,
-                'description': description,
-                'tomorrow': tomorrow,
-                'role1': role1,
-                'role2': role2,
-            }
         )
         self.addCleanup(
             self.openstack,
@@ -151,9 +129,7 @@ class ApplicationCredentialTests(common.IdentityTests):
     def test_application_credential_delete(self):
         name = data_utils.rand_name('name')
         self.openstack(f'application credential create {name}')
-        raw_output = self.openstack(
-            'application credential delete ' '%(name)s' % {'name': name}
-        )
+        raw_output = self.openstack('application credential delete ' f'{name}')
         self.assertEqual(0, len(raw_output))
 
     def test_application_credential_list(self):
@@ -170,8 +146,6 @@ class ApplicationCredentialTests(common.IdentityTests):
             self.openstack,
             f'application credential delete {name}',
         )
-        raw_output = self.openstack(
-            'application credential show ' '%(name)s' % {'name': name}
-        )
+        raw_output = self.openstack('application credential show ' f'{name}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.APPLICATION_CREDENTIAL_FIELDS)
diff --git a/openstackclient/tests/functional/identity/v3/test_catalog.py b/openstackclient/tests/functional/identity/v3/test_catalog.py
index 9b6df2d194..f4089b7eb8 100644
--- a/openstackclient/tests/functional/identity/v3/test_catalog.py
+++ b/openstackclient/tests/functional/identity/v3/test_catalog.py
@@ -38,7 +38,7 @@ class CatalogTests(common.IdentityTests):
         | type      | identity                               |
         +-----------+----------------------------------------+
         """
-        raw_output = self.openstack('catalog show %s' % 'identity')
+        raw_output = self.openstack('catalog show {}'.format('identity'))
         items = self.parse_show(raw_output)
         # items may have multiple endpoint urls with empty key
         self.assert_show_fields(items, ['endpoints', 'name', 'type', '', 'id'])
diff --git a/openstackclient/tests/functional/identity/v3/test_domain.py b/openstackclient/tests/functional/identity/v3/test_domain.py
index 08e0e07901..867db91df9 100644
--- a/openstackclient/tests/functional/identity/v3/test_domain.py
+++ b/openstackclient/tests/functional/identity/v3/test_domain.py
@@ -19,12 +19,10 @@ from openstackclient.tests.functional.identity.v3 import common
 class DomainTests(common.IdentityTests):
     def test_domain_create(self):
         domain_name = data_utils.rand_name('TestDomain')
-        raw_output = self.openstack('domain create %s' % domain_name)
+        raw_output = self.openstack(f'domain create {domain_name}')
         # disable domain first before deleting it
-        self.addCleanup(self.openstack, 'domain delete %s' % domain_name)
-        self.addCleanup(
-            self.openstack, 'domain set --disable %s' % domain_name
-        )
+        self.addCleanup(self.openstack, f'domain delete {domain_name}')
+        self.addCleanup(self.openstack, f'domain set --disable {domain_name}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.DOMAIN_FIELDS)
 
@@ -37,18 +35,18 @@ class DomainTests(common.IdentityTests):
     def test_domain_delete(self):
         domain_name = self._create_dummy_domain(add_clean_up=False)
         # cannot delete enabled domain, disable it first
-        raw_output = self.openstack('domain set --disable %s' % domain_name)
+        raw_output = self.openstack(f'domain set --disable {domain_name}')
         self.assertEqual(0, len(raw_output))
-        raw_output = self.openstack('domain delete %s' % domain_name)
+        raw_output = self.openstack(f'domain delete {domain_name}')
         self.assertEqual(0, len(raw_output))
 
     def test_domain_multi_delete(self):
         domain_1 = self._create_dummy_domain(add_clean_up=False)
         domain_2 = self._create_dummy_domain(add_clean_up=False)
         # cannot delete enabled domain, disable it first
-        raw_output = self.openstack('domain set --disable %s' % domain_1)
+        raw_output = self.openstack(f'domain set --disable {domain_1}')
         self.assertEqual(0, len(raw_output))
-        raw_output = self.openstack('domain set --disable %s' % domain_2)
+        raw_output = self.openstack(f'domain set --disable {domain_2}')
         self.assertEqual(0, len(raw_output))
         raw_output = self.openstack(f'domain delete {domain_1} {domain_2}')
         self.assertEqual(0, len(raw_output))
@@ -59,11 +57,11 @@ class DomainTests(common.IdentityTests):
         self.assertRaises(
             exceptions.CommandFailed,
             self.openstack,
-            'domain delete %s' % domain_name,
+            f'domain delete {domain_name}',
         )
 
     def test_domain_show(self):
         domain_name = self._create_dummy_domain()
-        raw_output = self.openstack('domain show %s' % domain_name)
+        raw_output = self.openstack(f'domain show {domain_name}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.DOMAIN_FIELDS)
diff --git a/openstackclient/tests/functional/identity/v3/test_endpoint.py b/openstackclient/tests/functional/identity/v3/test_endpoint.py
index 1fff6abeb4..cafab670a3 100644
--- a/openstackclient/tests/functional/identity/v3/test_endpoint.py
+++ b/openstackclient/tests/functional/identity/v3/test_endpoint.py
@@ -23,7 +23,7 @@ class EndpointTests(common.IdentityTests):
 
     def test_endpoint_delete(self):
         endpoint_id = self._create_dummy_endpoint(add_clean_up=False)
-        raw_output = self.openstack('endpoint delete %s' % endpoint_id)
+        raw_output = self.openstack(f'endpoint delete {endpoint_id}')
         self.assertEqual(0, len(raw_output))
 
     def test_endpoint_multi_delete(self):
@@ -45,20 +45,15 @@ class EndpointTests(common.IdentityTests):
         endpoint_id = self._create_dummy_endpoint(add_clean_up=False)
         project_id = self._create_dummy_project(add_clean_up=False)
         raw_output = self.openstack(
-            'endpoint add project '
-            '%(endpoint_id)s '
-            '%(project_id)s'
-            % {'project_id': project_id, 'endpoint_id': endpoint_id}
+            'endpoint add project ' f'{endpoint_id} ' f'{project_id}'
         )
         self.assertEqual(0, len(raw_output))
-        raw_output = self.openstack(
-            'endpoint list --endpoint %s' % endpoint_id
-        )
+        raw_output = self.openstack(f'endpoint list --endpoint {endpoint_id}')
         self.assertIn(project_id, raw_output)
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, self.ENDPOINT_LIST_PROJECT_HEADERS)
 
-        raw_output = self.openstack('endpoint list --project %s' % project_id)
+        raw_output = self.openstack(f'endpoint list --project {project_id}')
         self.assertIn(endpoint_id, raw_output)
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, self.ENDPOINT_LIST_HEADERS)
@@ -68,18 +63,17 @@ class EndpointTests(common.IdentityTests):
         new_endpoint_url = data_utils.rand_url()
         raw_output = self.openstack(
             'endpoint set '
-            '--interface %(interface)s '
-            '--url %(url)s '
+            '--interface {interface} '
+            '--url {url} '
             '--disable '
-            '%(endpoint_id)s'
-            % {
-                'interface': 'admin',
-                'url': new_endpoint_url,
-                'endpoint_id': endpoint_id,
-            }
+            '{endpoint_id}'.format(
+                interface='admin',
+                url=new_endpoint_url,
+                endpoint_id=endpoint_id,
+            )
         )
         self.assertEqual(0, len(raw_output))
-        raw_output = self.openstack('endpoint show %s' % endpoint_id)
+        raw_output = self.openstack(f'endpoint show {endpoint_id}')
         endpoint = self.parse_show_as_object(raw_output)
         self.assertEqual('admin', endpoint['interface'])
         self.assertEqual(new_endpoint_url, endpoint['url'])
@@ -87,7 +81,7 @@ class EndpointTests(common.IdentityTests):
 
     def test_endpoint_show(self):
         endpoint_id = self._create_dummy_endpoint()
-        raw_output = self.openstack('endpoint show %s' % endpoint_id)
+        raw_output = self.openstack(f'endpoint show {endpoint_id}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ENDPOINT_FIELDS)
 
@@ -95,17 +89,11 @@ class EndpointTests(common.IdentityTests):
         endpoint_id = self._create_dummy_endpoint(add_clean_up=False)
         project_id = self._create_dummy_project(add_clean_up=False)
         raw_output = self.openstack(
-            'endpoint add project '
-            '%(endpoint_id)s '
-            '%(project_id)s'
-            % {'project_id': project_id, 'endpoint_id': endpoint_id}
+            'endpoint add project ' f'{endpoint_id} ' f'{project_id}'
         )
         self.assertEqual(0, len(raw_output))
 
         raw_output = self.openstack(
-            'endpoint remove project '
-            '%(endpoint_id)s '
-            '%(project_id)s'
-            % {'project_id': project_id, 'endpoint_id': endpoint_id}
+            'endpoint remove project ' f'{endpoint_id} ' f'{project_id}'
         )
         self.assertEqual(0, len(raw_output))
diff --git a/openstackclient/tests/functional/identity/v3/test_group.py b/openstackclient/tests/functional/identity/v3/test_group.py
index 95d74cb76c..5fc1ed39c3 100644
--- a/openstackclient/tests/functional/identity/v3/test_group.py
+++ b/openstackclient/tests/functional/identity/v3/test_group.py
@@ -28,9 +28,7 @@ class GroupTests(common.IdentityTests):
 
     def test_group_list_with_domain(self):
         group_name = self._create_dummy_group()
-        raw_output = self.openstack(
-            'group list --domain %s' % self.domain_name
-        )
+        raw_output = self.openstack(f'group list --domain {self.domain_name}')
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, common.BASIC_LIST_HEADERS)
         self.assertIn(group_name, raw_output)
@@ -38,18 +36,14 @@ class GroupTests(common.IdentityTests):
     def test_group_delete(self):
         group_name = self._create_dummy_group(add_clean_up=False)
         raw_output = self.openstack(
-            'group delete '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': group_name}
+            'group delete ' f'--domain {self.domain_name} ' f'{group_name}'
         )
         self.assertEqual(0, len(raw_output))
 
     def test_group_show(self):
         group_name = self._create_dummy_group()
         raw_output = self.openstack(
-            'group show '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': group_name}
+            'group show ' f'--domain {self.domain_name} ' f'{group_name}'
         )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.GROUP_FIELDS)
@@ -59,34 +53,22 @@ class GroupTests(common.IdentityTests):
         new_group_name = data_utils.rand_name('NewTestGroup')
         raw_output = self.openstack(
             'group set '
-            '--domain %(domain)s '
-            '--name %(new_group)s '
-            '%(group)s'
-            % {
-                'domain': self.domain_name,
-                'new_group': new_group_name,
-                'group': group_name,
-            }
+            f'--domain {self.domain_name} '
+            f'--name {new_group_name} '
+            f'{group_name}'
         )
         self.assertEqual(0, len(raw_output))
         raw_output = self.openstack(
-            'group show '
-            '--domain %(domain)s '
-            '%(group)s' % {'domain': self.domain_name, 'group': new_group_name}
+            'group show ' f'--domain {self.domain_name} ' f'{new_group_name}'
         )
         group = self.parse_show_as_object(raw_output)
         self.assertEqual(new_group_name, group['name'])
         # reset group name to make sure it will be cleaned up
         raw_output = self.openstack(
             'group set '
-            '--domain %(domain)s '
-            '--name %(new_group)s '
-            '%(group)s'
-            % {
-                'domain': self.domain_name,
-                'new_group': group_name,
-                'group': new_group_name,
-            }
+            f'--domain {self.domain_name} '
+            f'--name {group_name} '
+            f'{new_group_name}'
         )
         self.assertEqual(0, len(raw_output))
 
@@ -95,28 +77,16 @@ class GroupTests(common.IdentityTests):
         username = self._create_dummy_user()
         raw_output = self.openstack(
             'group add user '
-            '--group-domain %(group_domain)s '
-            '--user-domain %(user_domain)s '
-            '%(group)s %(user)s'
-            % {
-                'group_domain': self.domain_name,
-                'user_domain': self.domain_name,
-                'group': group_name,
-                'user': username,
-            }
+            f'--group-domain {self.domain_name} '
+            f'--user-domain {self.domain_name} '
+            f'{group_name} {username}'
         )
         self.addCleanup(
             self.openstack,
             'group remove user '
-            '--group-domain %(group_domain)s '
-            '--user-domain %(user_domain)s '
-            '%(group)s %(user)s'
-            % {
-                'group_domain': self.domain_name,
-                'user_domain': self.domain_name,
-                'group': group_name,
-                'user': username,
-            },
+            f'--group-domain {self.domain_name} '
+            f'--user-domain {self.domain_name} '
+            f'{group_name} {username}',
         )
         self.assertOutput('', raw_output)
 
@@ -125,45 +95,26 @@ class GroupTests(common.IdentityTests):
         username = self._create_dummy_user()
         raw_output = self.openstack(
             'group add user '
-            '--group-domain %(group_domain)s '
-            '--user-domain %(user_domain)s '
-            '%(group)s %(user)s'
-            % {
-                'group_domain': self.domain_name,
-                'user_domain': self.domain_name,
-                'group': group_name,
-                'user': username,
-            }
+            f'--group-domain {self.domain_name} '
+            f'--user-domain {self.domain_name} '
+            f'{group_name} {username}'
         )
         self.addCleanup(
             self.openstack,
             'group remove user '
-            '--group-domain %(group_domain)s '
-            '--user-domain %(user_domain)s '
-            '%(group)s %(user)s'
-            % {
-                'group_domain': self.domain_name,
-                'user_domain': self.domain_name,
-                'group': group_name,
-                'user': username,
-            },
+            f'--group-domain {self.domain_name} '
+            f'--user-domain {self.domain_name} '
+            f'{group_name} {username}',
         )
         self.assertOutput('', raw_output)
         raw_output = self.openstack(
             'group contains user '
-            '--group-domain %(group_domain)s '
-            '--user-domain %(user_domain)s '
-            '%(group)s %(user)s'
-            % {
-                'group_domain': self.domain_name,
-                'user_domain': self.domain_name,
-                'group': group_name,
-                'user': username,
-            }
+            f'--group-domain {self.domain_name} '
+            f'--user-domain {self.domain_name} '
+            f'{group_name} {username}'
         )
         self.assertEqual(
-            '%(user)s in group %(group)s\n'
-            % {'user': username, 'group': group_name},
+            f'{username} in group {group_name}\n',
             raw_output,
         )
 
@@ -172,27 +123,15 @@ class GroupTests(common.IdentityTests):
         username = self._create_dummy_user()
         add_raw_output = self.openstack(
             'group add user '
-            '--group-domain %(group_domain)s '
-            '--user-domain %(user_domain)s '
-            '%(group)s %(user)s'
-            % {
-                'group_domain': self.domain_name,
-                'user_domain': self.domain_name,
-                'group': group_name,
-                'user': username,
-            }
+            f'--group-domain {self.domain_name} '
+            f'--user-domain {self.domain_name} '
+            f'{group_name} {username}'
         )
         remove_raw_output = self.openstack(
             'group remove user '
-            '--group-domain %(group_domain)s '
-            '--user-domain %(user_domain)s '
-            '%(group)s %(user)s'
-            % {
-                'group_domain': self.domain_name,
-                'user_domain': self.domain_name,
-                'group': group_name,
-                'user': username,
-            }
+            f'--group-domain {self.domain_name} '
+            f'--user-domain {self.domain_name} '
+            f'{group_name} {username}'
         )
         self.assertOutput('', add_raw_output)
         self.assertOutput('', remove_raw_output)
diff --git a/openstackclient/tests/functional/identity/v3/test_idp.py b/openstackclient/tests/functional/identity/v3/test_idp.py
index 05f3ee84ee..11275795b2 100644
--- a/openstackclient/tests/functional/identity/v3/test_idp.py
+++ b/openstackclient/tests/functional/identity/v3/test_idp.py
@@ -24,7 +24,7 @@ class IdentityProviderTests(common.IdentityTests):
     def test_idp_delete(self):
         identity_provider = self._create_dummy_idp(add_clean_up=False)
         raw_output = self.openstack(
-            'identity provider delete %s' % identity_provider
+            f'identity provider delete {identity_provider}'
         )
         self.assertEqual(0, len(raw_output))
 
@@ -39,7 +39,7 @@ class IdentityProviderTests(common.IdentityTests):
     def test_idp_show(self):
         identity_provider = self._create_dummy_idp(add_clean_up=True)
         raw_output = self.openstack(
-            'identity provider show %s' % identity_provider
+            f'identity provider show {identity_provider}'
         )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.IDENTITY_PROVIDER_FIELDS)
@@ -64,7 +64,7 @@ class IdentityProviderTests(common.IdentityTests):
         )
         self.assertEqual(0, len(raw_output))
         raw_output = self.openstack(
-            'identity provider show %s' % identity_provider
+            f'identity provider show {identity_provider}'
         )
         updated_value = self.parse_show_as_object(raw_output)
         self.assertIn(new_remoteid, updated_value['remote_ids'])
diff --git a/openstackclient/tests/functional/identity/v3/test_limit.py b/openstackclient/tests/functional/identity/v3/test_limit.py
index 32c65107d0..79213308d2 100644
--- a/openstackclient/tests/functional/identity/v3/test_limit.py
+++ b/openstackclient/tests/functional/identity/v3/test_limit.py
@@ -23,19 +23,19 @@ class LimitTestCase(common.IdentityTests):
     def test_limit_create_with_service_name(self):
         registered_limit_id = self._create_dummy_registered_limit()
         raw_output = self.openstack(
-            'registered limit show %s' % registered_limit_id,
+            f'registered limit show {registered_limit_id}',
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
         service_id = self._extract_value_from_items('service_id', items)
         resource_name = self._extract_value_from_items('resource_name', items)
 
-        raw_output = self.openstack('service show %s' % service_id)
+        raw_output = self.openstack(f'service show {service_id}')
         items = self.parse_show(raw_output)
         service_name = self._extract_value_from_items('name', items)
 
         project_name = self._create_dummy_project()
-        raw_output = self.openstack('project show %s' % project_name)
+        raw_output = self.openstack(f'project show {project_name}')
         items = self.parse_show(raw_output)
         project_id = self._extract_value_from_items('id', items)
 
@@ -47,16 +47,16 @@ class LimitTestCase(common.IdentityTests):
         }
         raw_output = self.openstack(
             'limit create'
-            ' --project %(project_id)s'
-            ' --service %(service_name)s'
-            ' --resource-limit %(resource_limit)s'
-            ' %(resource_name)s' % params,
+            ' --project {project_id}'
+            ' --service {service_name}'
+            ' --resource-limit {resource_limit}'
+            ' {resource_name}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
         limit_id = self._extract_value_from_items('id', items)
         self.addCleanup(
-            self.openstack, 'limit delete %s' % limit_id, cloud=SYSTEM_CLOUD
+            self.openstack, f'limit delete {limit_id}', cloud=SYSTEM_CLOUD
         )
 
         self.assert_show_fields(items, self.LIMIT_FIELDS)
@@ -64,14 +64,14 @@ class LimitTestCase(common.IdentityTests):
     def test_limit_create_with_project_name(self):
         registered_limit_id = self._create_dummy_registered_limit()
         raw_output = self.openstack(
-            'registered limit show %s' % registered_limit_id,
+            f'registered limit show {registered_limit_id}',
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
         service_id = self._extract_value_from_items('service_id', items)
         resource_name = self._extract_value_from_items('resource_name', items)
 
-        raw_output = self.openstack('service show %s' % service_id)
+        raw_output = self.openstack(f'service show {service_id}')
         items = self.parse_show(raw_output)
         service_name = self._extract_value_from_items('name', items)
 
@@ -85,16 +85,16 @@ class LimitTestCase(common.IdentityTests):
         }
         raw_output = self.openstack(
             'limit create'
-            ' --project %(project_name)s'
-            ' --service %(service_name)s'
-            ' --resource-limit %(resource_limit)s'
-            ' %(resource_name)s' % params,
+            ' --project {project_name}'
+            ' --service {service_name}'
+            ' --resource-limit {resource_limit}'
+            ' {resource_name}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
         limit_id = self._extract_value_from_items('id', items)
         self.addCleanup(
-            self.openstack, 'limit delete %s' % limit_id, cloud=SYSTEM_CLOUD
+            self.openstack, f'limit delete {limit_id}', cloud=SYSTEM_CLOUD
         )
 
         self.assert_show_fields(items, self.LIMIT_FIELDS)
@@ -117,8 +117,8 @@ class LimitTestCase(common.IdentityTests):
 
         raw_output = self.openstack(
             'registered limit set'
-            ' %(registered_limit_id)s'
-            ' --region %(region_id)s' % params,
+            ' {registered_limit_id}'
+            ' --region {region_id}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -126,7 +126,7 @@ class LimitTestCase(common.IdentityTests):
         resource_name = self._extract_value_from_items('resource_name', items)
 
         project_name = self._create_dummy_project()
-        raw_output = self.openstack('project show %s' % project_name)
+        raw_output = self.openstack(f'project show {project_name}')
         items = self.parse_show(raw_output)
         project_id = self._extract_value_from_items('id', items)
         description = data_utils.arbitrary_string()
@@ -141,18 +141,18 @@ class LimitTestCase(common.IdentityTests):
         }
         raw_output = self.openstack(
             'limit create'
-            ' --project %(project_id)s'
-            ' --service %(service_id)s'
-            ' --resource-limit %(resource_limit)s'
-            ' --region %(region_id)s'
-            ' --description %(description)s'
-            ' %(resource_name)s' % params,
+            ' --project {project_id}'
+            ' --service {service_id}'
+            ' --resource-limit {resource_limit}'
+            ' --region {region_id}'
+            ' --description {description}'
+            ' {resource_name}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
         limit_id = self._extract_value_from_items('id', items)
         self.addCleanup(
-            self.openstack, 'limit delete %s' % limit_id, cloud=SYSTEM_CLOUD
+            self.openstack, f'limit delete {limit_id}', cloud=SYSTEM_CLOUD
         )
 
         self.assert_show_fields(items, self.LIMIT_FIELDS)
@@ -160,7 +160,7 @@ class LimitTestCase(common.IdentityTests):
     def test_limit_show(self):
         limit_id = self._create_dummy_limit()
         raw_output = self.openstack(
-            'limit show %s' % limit_id, cloud=SYSTEM_CLOUD
+            f'limit show {limit_id}', cloud=SYSTEM_CLOUD
         )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.LIMIT_FIELDS)
@@ -174,9 +174,9 @@ class LimitTestCase(common.IdentityTests):
         }
 
         raw_output = self.openstack(
-            'limit set'
-            ' --description %(description)s'
-            ' %(limit_id)s' % params,
+            'limit set' ' --description {description}' ' {limit_id}'.format(
+                **params
+            ),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -189,8 +189,8 @@ class LimitTestCase(common.IdentityTests):
 
         raw_output = self.openstack(
             'limit set'
-            ' --resource-limit %(resource_limit)s'
-            ' %(limit_id)s' % params,
+            ' --resource-limit {resource_limit}'
+            ' {limit_id}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -205,6 +205,6 @@ class LimitTestCase(common.IdentityTests):
     def test_limit_delete(self):
         limit_id = self._create_dummy_limit(add_clean_up=False)
         raw_output = self.openstack(
-            'limit delete %s' % limit_id, cloud=SYSTEM_CLOUD
+            f'limit delete {limit_id}', cloud=SYSTEM_CLOUD
         )
         self.assertEqual(0, len(raw_output))
diff --git a/openstackclient/tests/functional/identity/v3/test_project.py b/openstackclient/tests/functional/identity/v3/test_project.py
index d91ba87a88..9115c0e1af 100644
--- a/openstackclient/tests/functional/identity/v3/test_project.py
+++ b/openstackclient/tests/functional/identity/v3/test_project.py
@@ -21,23 +21,18 @@ class ProjectTests(common.IdentityTests):
         description = data_utils.rand_name('description')
         raw_output = self.openstack(
             'project create '
-            '--domain %(domain)s '
-            '--description %(description)s '
+            f'--domain {self.domain_name} '
+            f'--description {description} '
             '--enable '
             '--property k1=v1 '
             '--property k2=v2 '
-            '%(name)s'
-            % {
-                'domain': self.domain_name,
-                'description': description,
-                'name': project_name,
-            }
+            f'{project_name}'
         )
         self.addCleanup(
             self.openstack,
             'project delete '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': project_name},
+            f'--domain {self.domain_name} '
+            f'{project_name}',
         )
         items = self.parse_show(raw_output)
         show_fields = list(self.PROJECT_FIELDS)
@@ -50,9 +45,7 @@ class ProjectTests(common.IdentityTests):
     def test_project_delete(self):
         project_name = self._create_dummy_project(add_clean_up=False)
         raw_output = self.openstack(
-            'project delete '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': project_name}
+            'project delete ' f'--domain {self.domain_name} ' f'{project_name}'
         )
         self.assertEqual(0, len(raw_output))
 
@@ -64,7 +57,7 @@ class ProjectTests(common.IdentityTests):
     def test_project_list_with_domain(self):
         project_name = self._create_dummy_project()
         raw_output = self.openstack(
-            'project list --domain %s' % self.domain_name
+            f'project list --domain {self.domain_name}'
         )
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, common.BASIC_LIST_HEADERS)
@@ -76,17 +69,17 @@ class ProjectTests(common.IdentityTests):
         new_project_name = data_utils.rand_name('NewTestProject')
         raw_output = self.openstack(
             'project set '
-            '--name %(new_name)s '
+            f'--name {new_project_name} '
             '--disable '
             '--property k0=v0 '
-            '%(name)s' % {'new_name': new_project_name, 'name': project_name}
+            f'{project_name}'
         )
         self.assertEqual(0, len(raw_output))
         # check project details
         raw_output = self.openstack(
             'project show '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': new_project_name}
+            f'--domain {self.domain_name} '
+            f'{new_project_name}'
         )
         items = self.parse_show(raw_output)
         fields = list(self.PROJECT_FIELDS)
@@ -99,17 +92,16 @@ class ProjectTests(common.IdentityTests):
         # reset project to make sure it will be cleaned up
         self.openstack(
             'project set '
-            '--name %(new_name)s '
+            f'--name {project_name} '
             '--enable '
-            '%(name)s' % {'new_name': project_name, 'name': new_project_name}
+            f'{new_project_name}'
         )
 
     def test_project_show(self):
         raw_output = self.openstack(
             'project show '
-            '--domain %(domain)s '
-            '%(name)s'
-            % {'domain': self.domain_name, 'name': self.project_name}
+            f'--domain {self.domain_name} '
+            f'{self.project_name}'
         )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.PROJECT_FIELDS)
@@ -118,9 +110,8 @@ class ProjectTests(common.IdentityTests):
         output = self.openstack(
             'project show '
             '--parents --children '
-            '--domain %(domain)s '
-            '%(name)s'
-            % {'domain': self.domain_name, 'name': self.project_name},
+            f'--domain {self.domain_name} '
+            f'{self.project_name}',
             parse_output=True,
         )
         for attr_name in self.PROJECT_FIELDS + ['parents', 'subtree']:
diff --git a/openstackclient/tests/functional/identity/v3/test_region.py b/openstackclient/tests/functional/identity/v3/test_region.py
index 48ca837814..16133f8941 100644
--- a/openstackclient/tests/functional/identity/v3/test_region.py
+++ b/openstackclient/tests/functional/identity/v3/test_region.py
@@ -23,7 +23,7 @@ class RegionTests(common.IdentityTests):
 
     def test_region_delete(self):
         region_id = self._create_dummy_region(add_clean_up=False)
-        raw_output = self.openstack('region delete %s' % region_id)
+        raw_output = self.openstack(f'region delete {region_id}')
         self.assertEqual(0, len(raw_output))
 
     def test_region_multi_delete(self):
@@ -43,27 +43,26 @@ class RegionTests(common.IdentityTests):
         new_parent_region_id = self._create_dummy_region()
         region_id = self._create_dummy_region(parent_region_id)
         # check region details
-        raw_output = self.openstack('region show %s' % region_id)
+        raw_output = self.openstack(f'region show {region_id}')
         region = self.parse_show_as_object(raw_output)
         self.assertEqual(parent_region_id, region['parent_region'])
         self.assertEqual(region_id, region['region'])
         # update parent-region
         raw_output = self.openstack(
             'region set '
-            '--parent-region %(parent_region)s '
-            '%(region)s'
-            % {'parent_region': new_parent_region_id, 'region': region_id}
+            f'--parent-region {new_parent_region_id} '
+            f'{region_id}'
         )
         self.assertEqual(0, len(raw_output))
         # check updated region details
-        raw_output = self.openstack('region show %s' % region_id)
+        raw_output = self.openstack(f'region show {region_id}')
         region = self.parse_show_as_object(raw_output)
         self.assertEqual(new_parent_region_id, region['parent_region'])
         self.assertEqual(region_id, region['region'])
 
     def test_region_show(self):
         region_id = self._create_dummy_region()
-        raw_output = self.openstack('region show %s' % region_id)
+        raw_output = self.openstack(f'region show {region_id}')
         region = self.parse_show_as_object(raw_output)
         self.assertEqual(region_id, region['region'])
         self.assertEqual('None', region['parent_region'])
diff --git a/openstackclient/tests/functional/identity/v3/test_registered_limit.py b/openstackclient/tests/functional/identity/v3/test_registered_limit.py
index 6e3c30aeb0..f91b47fc4b 100644
--- a/openstackclient/tests/functional/identity/v3/test_registered_limit.py
+++ b/openstackclient/tests/functional/identity/v3/test_registered_limit.py
@@ -25,31 +25,26 @@ class RegisteredLimitTestCase(common.IdentityTests):
 
     def test_registered_limit_create_with_service_id(self):
         service_name = self._create_dummy_service()
-        raw_output = self.openstack(
-            'service show' ' %(service_name)s' % {'service_name': service_name}
-        )
+        raw_output = self.openstack('service show' f' {service_name}')
         service_items = self.parse_show(raw_output)
         service_id = self._extract_value_from_items('id', service_items)
 
         raw_output = self.openstack(
             'registered limit create'
-            ' --service %(service_id)s'
-            ' --default-limit %(default_limit)s'
-            ' %(resource_name)s'
-            % {
-                'service_id': service_id,
-                'default_limit': 10,
-                'resource_name': 'cores',
-            },
+            ' --service {service_id}'
+            ' --default-limit {default_limit}'
+            ' {resource_name}'.format(
+                service_id=service_id,
+                default_limit=10,
+                resource_name='cores',
+            ),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
         registered_limit_id = self._extract_value_from_items('id', items)
         self.addCleanup(
             self.openstack,
-            'registered limit delete'
-            ' %(registered_limit_id)s'
-            % {'registered_limit_id': registered_limit_id},
+            'registered limit delete' f' {registered_limit_id}',
             cloud=SYSTEM_CLOUD,
         )
 
@@ -68,19 +63,18 @@ class RegisteredLimitTestCase(common.IdentityTests):
 
         raw_output = self.openstack(
             'registered limit create'
-            ' --description \'%(description)s\''
-            ' --region %(region_id)s'
-            ' --service %(service_name)s'
-            ' --default-limit %(default_limit)s'
-            ' %(resource_name)s' % params,
+            ' --description \'{description}\''
+            ' --region {region_id}'
+            ' --service {service_name}'
+            ' --default-limit {default_limit}'
+            ' {resource_name}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
         registered_limit_id = self._extract_value_from_items('id', items)
         self.addCleanup(
             self.openstack,
-            'registered limit delete %(registered_limit_id)s'
-            % {'registered_limit_id': registered_limit_id},
+            f'registered limit delete {registered_limit_id}',
             cloud=SYSTEM_CLOUD,
         )
 
@@ -89,8 +83,7 @@ class RegisteredLimitTestCase(common.IdentityTests):
     def test_registered_limit_show(self):
         registered_limit_id = self._create_dummy_registered_limit()
         raw_output = self.openstack(
-            'registered limit show %(registered_limit_id)s'
-            % {'registered_limit_id': registered_limit_id}
+            f'registered limit show {registered_limit_id}'
         )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.REGISTERED_LIMIT_FIELDS)
@@ -105,8 +98,8 @@ class RegisteredLimitTestCase(common.IdentityTests):
         }
         raw_output = self.openstack(
             'registered limit set'
-            ' %(registered_limit_id)s'
-            ' --region %(region_id)s' % params,
+            ' {registered_limit_id}'
+            ' --region {region_id}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -120,8 +113,8 @@ class RegisteredLimitTestCase(common.IdentityTests):
         }
         raw_output = self.openstack(
             'registered limit set'
-            ' %(registered_limit_id)s'
-            ' --description \'%(description)s\'' % params,
+            ' {registered_limit_id}'
+            ' --description \'{description}\''.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -136,8 +129,8 @@ class RegisteredLimitTestCase(common.IdentityTests):
         }
         raw_output = self.openstack(
             'registered limit set'
-            ' %(registered_limit_id)s'
-            ' --service %(service)s' % params,
+            ' {registered_limit_id}'
+            ' --service {service}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -151,8 +144,8 @@ class RegisteredLimitTestCase(common.IdentityTests):
         }
         raw_output = self.openstack(
             'registered limit set'
-            ' %(registered_limit_id)s'
-            ' --default-limit %(default_limit)s' % params,
+            ' {registered_limit_id}'
+            ' --default-limit {default_limit}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -167,8 +160,8 @@ class RegisteredLimitTestCase(common.IdentityTests):
         }
         raw_output = self.openstack(
             'registered limit set'
-            ' %(registered_limit_id)s'
-            ' --resource-name %(resource_name)s' % params,
+            ' {registered_limit_id}'
+            ' --resource-name {resource_name}'.format(**params),
             cloud=SYSTEM_CLOUD,
         )
         items = self.parse_show(raw_output)
@@ -185,9 +178,7 @@ class RegisteredLimitTestCase(common.IdentityTests):
             add_clean_up=False
         )
         raw_output = self.openstack(
-            'registered limit delete'
-            ' %(registered_limit_id)s'
-            % {'registered_limit_id': registered_limit_id},
+            'registered limit delete' f' {registered_limit_id}',
             cloud=SYSTEM_CLOUD,
         )
         self.assertEqual(0, len(raw_output))
diff --git a/openstackclient/tests/functional/identity/v3/test_role.py b/openstackclient/tests/functional/identity/v3/test_role.py
index 9a1aa648f6..16ddc23a3d 100644
--- a/openstackclient/tests/functional/identity/v3/test_role.py
+++ b/openstackclient/tests/functional/identity/v3/test_role.py
@@ -23,12 +23,10 @@ class RoleTests(common.IdentityTests):
         role_name = data_utils.rand_name('TestRole')
         description = data_utils.rand_name('description')
         raw_output = self.openstack(
-            'role create '
-            '--description %(description)s '
-            '%(name)s' % {'description': description, 'name': role_name}
+            'role create ' f'--description {description} ' f'{role_name}'
         )
         role = self.parse_show_as_object(raw_output)
-        self.addCleanup(self.openstack, 'role delete %s' % role['id'])
+        self.addCleanup(self.openstack, 'role delete {}'.format(role['id']))
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ROLE_FIELDS)
         self.assertEqual(description, role['description'])
@@ -36,7 +34,7 @@ class RoleTests(common.IdentityTests):
 
     def test_role_delete(self):
         role_name = self._create_dummy_role(add_clean_up=False)
-        raw_output = self.openstack('role delete %s' % role_name)
+        raw_output = self.openstack(f'role delete {role_name}')
         self.assertEqual(0, len(raw_output))
 
     def test_role_list(self):
@@ -47,7 +45,7 @@ class RoleTests(common.IdentityTests):
 
     def test_role_show(self):
         role_name = self._create_dummy_role()
-        raw_output = self.openstack('role show %s' % role_name)
+        raw_output = self.openstack(f'role show {role_name}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.ROLE_FIELDS)
 
@@ -58,7 +56,7 @@ class RoleTests(common.IdentityTests):
             f'role set --name {new_role_name} {role_name}'
         )
         self.assertEqual(0, len(raw_output))
-        raw_output = self.openstack('role show %s' % new_role_name)
+        raw_output = self.openstack(f'role show {new_role_name}')
         role = self.parse_show_as_object(raw_output)
         self.assertEqual(new_role_name, role['name'])
 
@@ -69,7 +67,7 @@ class RoleTests(common.IdentityTests):
             f'role set --description {description} {role_name}'
         )
         self.assertEqual(0, len(raw_output))
-        raw_output = self.openstack('role show %s' % role_name)
+        raw_output = self.openstack(f'role show {role_name}')
         role = self.parse_show_as_object(raw_output)
         self.assertEqual(description, role['description'])
 
@@ -78,34 +76,20 @@ class RoleTests(common.IdentityTests):
         username = self._create_dummy_user()
         raw_output = self.openstack(
             'role add '
-            '--project %(project)s '
-            '--project-domain %(project_domain)s '
-            '--user %(user)s '
-            '--user-domain %(user_domain)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'project_domain': self.domain_name,
-                'user': username,
-                'user_domain': self.domain_name,
-                'role': role_name,
-            }
+            f'--project {self.project_name} '
+            f'--project-domain {self.domain_name} '
+            f'--user {username} '
+            f'--user-domain {self.domain_name} '
+            f'{role_name}'
         )
         self.addCleanup(
             self.openstack,
             'role remove '
-            '--project %(project)s '
-            '--project-domain %(project_domain)s '
-            '--user %(user)s '
-            '--user-domain %(user_domain)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'project_domain': self.domain_name,
-                'user': username,
-                'user_domain': self.domain_name,
-                'role': role_name,
-            },
+            f'--project {self.project_name} '
+            f'--project-domain {self.domain_name} '
+            f'--user {username} '
+            f'--user-domain {self.domain_name} '
+            f'{role_name}',
         )
         self.assertEqual(0, len(raw_output))
 
@@ -114,33 +98,19 @@ class RoleTests(common.IdentityTests):
         username = self._create_dummy_user()
         add_raw_output = self.openstack(
             'role add '
-            '--project %(project)s '
-            '--project-domain %(project_domain)s '
-            '--user %(user)s '
-            '--user-domain %(user_domain)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'project_domain': self.domain_name,
-                'user': username,
-                'user_domain': self.domain_name,
-                'role': role_name,
-            }
+            f'--project {self.project_name} '
+            f'--project-domain {self.domain_name} '
+            f'--user {username} '
+            f'--user-domain {self.domain_name} '
+            f'{role_name}'
         )
         remove_raw_output = self.openstack(
             'role remove '
-            '--project %(project)s '
-            '--project-domain %(project_domain)s '
-            '--user %(user)s '
-            '--user-domain %(user_domain)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'project_domain': self.domain_name,
-                'user': username,
-                'user_domain': self.domain_name,
-                'role': role_name,
-            }
+            f'--project {self.project_name} '
+            f'--project-domain {self.domain_name} '
+            f'--user {username} '
+            f'--user-domain {self.domain_name} '
+            f'{role_name}'
         )
         self.assertEqual(0, len(add_raw_output))
         self.assertEqual(0, len(remove_raw_output))
@@ -165,15 +135,15 @@ class RoleTests(common.IdentityTests):
         implied_role_name = self._create_dummy_role()
         self.openstack(
             'implied role create '
-            '--implied-role %(implied_role)s '
-            '%(role)s' % {'implied_role': implied_role_name, 'role': role_name}
+            f'--implied-role {implied_role_name} '
+            f'{role_name}'
         )
 
     def test_implied_role_delete(self):
         implied_role_name, role_name = self._create_dummy_implied_role()
         raw_output = self.openstack(
             'implied role delete '
-            '--implied-role %(implied_role)s '
-            '%(role)s' % {'implied_role': implied_role_name, 'role': role_name}
+            f'--implied-role {implied_role_name} '
+            f'{role_name}'
         )
         self.assertEqual(0, len(raw_output))
diff --git a/openstackclient/tests/functional/identity/v3/test_role_assignment.py b/openstackclient/tests/functional/identity/v3/test_role_assignment.py
index a3927e7e1e..941563c7bd 100644
--- a/openstackclient/tests/functional/identity/v3/test_role_assignment.py
+++ b/openstackclient/tests/functional/identity/v3/test_role_assignment.py
@@ -25,43 +25,33 @@ class RoleAssignmentTests(common.IdentityTests):
         system = 'all'
         raw_output = self.openstack(
             'role add '
-            '--user %(user)s '
-            '--system %(system)s '
-            '%(role)s'
-            % {
-                'user': username,
-                'system': system,
-                'role': role_name,
-            }
+            f'--user {username} '
+            f'--system {system} '
+            f'{role_name}'
         )
         self.addCleanup(
             self.openstack,
             'role remove '
-            '--user %(user)s '
-            '--system  %(system)s '
-            '%(role)s'
-            % {
-                'user': username,
-                'system': system,
-                'role': role_name,
-            },
+            f'--user {username} '
+            f'--system  {system} '
+            f'{role_name}',
         )
         self.assertEqual(0, len(raw_output))
 
         raw_output = self.openstack(
-            'role assignment list ' '--user %(user)s ' % {'user': username}
+            'role assignment list ' f'--user {username} '
         )
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, self.ROLE_ASSIGNMENT_LIST_HEADERS)
 
         raw_output = self.openstack(
-            'role assignment list ' '--role %(role)s ' % {'role': role_name}
+            'role assignment list ' f'--role {role_name} '
         )
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, self.ROLE_ASSIGNMENT_LIST_HEADERS)
 
         raw_output = self.openstack(
-            'role assignment list ' '--system %(system)s ' % {'system': system}
+            'role assignment list ' f'--system {system} '
         )
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, self.ROLE_ASSIGNMENT_LIST_HEADERS)
@@ -72,30 +62,20 @@ class RoleAssignmentTests(common.IdentityTests):
         system = 'all'
         raw_output = self.openstack(
             'role add '
-            '--group %(group)s '
-            '--system %(system)s '
-            '%(role)s'
-            % {
-                'group': group,
-                'system': system,
-                'role': role_name,
-            }
+            f'--group {group} '
+            f'--system {system} '
+            f'{role_name}'
         )
         self.addCleanup(
             self.openstack,
             'role remove '
-            '--group %(group)s '
-            '--system %(system)s '
-            '%(role)s'
-            % {
-                'group': group,
-                'system': system,
-                'role': role_name,
-            },
+            f'--group {group} '
+            f'--system {system} '
+            f'{role_name}',
         )
         self.assertEqual(0, len(raw_output))
         raw_output = self.openstack(
-            'role assignment list ' '--group %(group)s ' % {'group': group}
+            'role assignment list ' f'--group {group} '
         )
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, self.ROLE_ASSIGNMENT_LIST_HEADERS)
@@ -105,31 +85,20 @@ class RoleAssignmentTests(common.IdentityTests):
         username = self._create_dummy_user()
         raw_output = self.openstack(
             'role add '
-            '--domain %(domain)s '
-            '--user %(user)s '
-            '%(role)s'
-            % {
-                'domain': self.domain_name,
-                'user': username,
-                'role': role_name,
-            }
+            f'--domain {self.domain_name} '
+            f'--user {username} '
+            f'{role_name}'
         )
         self.addCleanup(
             self.openstack,
             'role remove '
-            '--domain %(domain)s '
-            '--user %(user)s '
-            '%(role)s'
-            % {
-                'domain': self.domain_name,
-                'user': username,
-                'role': role_name,
-            },
+            f'--domain {self.domain_name} '
+            f'--user {username} '
+            f'{role_name}',
         )
         self.assertEqual(0, len(raw_output))
         raw_output = self.openstack(
-            'role assignment list '
-            '--domain %(domain)s ' % {'domain': self.domain_name}
+            'role assignment list ' f'--domain {self.domain_name} '
         )
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, self.ROLE_ASSIGNMENT_LIST_HEADERS)
@@ -139,31 +108,20 @@ class RoleAssignmentTests(common.IdentityTests):
         username = self._create_dummy_user()
         raw_output = self.openstack(
             'role add '
-            '--project %(project)s '
-            '--user %(user)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'user': username,
-                'role': role_name,
-            }
+            f'--project {self.project_name} '
+            f'--user {username} '
+            f'{role_name}'
         )
         self.addCleanup(
             self.openstack,
             'role remove '
-            '--project %(project)s '
-            '--user %(user)s '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'user': username,
-                'role': role_name,
-            },
+            f'--project {self.project_name} '
+            f'--user {username} '
+            f'{role_name}',
         )
         self.assertEqual(0, len(raw_output))
         raw_output = self.openstack(
-            'role assignment list '
-            '--project %(project)s ' % {'project': self.project_name}
+            'role assignment list ' f'--project {self.project_name} '
         )
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, self.ROLE_ASSIGNMENT_LIST_HEADERS)
@@ -188,15 +146,10 @@ class RoleAssignmentTests(common.IdentityTests):
         username = self._create_dummy_user()
         raw_output = self.openstack(
             'role add '
-            '--project %(project)s '
-            '--user %(user)s '
+            f'--project {self.project_name} '
+            f'--user {username} '
             '--inherited '
-            '%(role)s'
-            % {
-                'project': self.project_name,
-                'user': username,
-                'role': role_name,
-            }
+            f'{role_name}'
         )
         self.assertEqual(0, len(raw_output))
 
diff --git a/openstackclient/tests/functional/identity/v3/test_service.py b/openstackclient/tests/functional/identity/v3/test_service.py
index 98fa349d1e..7e102bacb7 100644
--- a/openstackclient/tests/functional/identity/v3/test_service.py
+++ b/openstackclient/tests/functional/identity/v3/test_service.py
@@ -21,7 +21,7 @@ class ServiceTests(common.IdentityTests):
 
     def test_service_delete(self):
         service_name = self._create_dummy_service(add_clean_up=False)
-        raw_output = self.openstack('service delete %s' % service_name)
+        raw_output = self.openstack(f'service delete {service_name}')
         self.assertEqual(0, len(raw_output))
 
     def test_service_multi_delete(self):
@@ -44,21 +44,15 @@ class ServiceTests(common.IdentityTests):
         new_service_type = data_utils.rand_name('NewTestType')
         raw_output = self.openstack(
             'service set '
-            '--type %(type)s '
-            '--name %(name)s '
-            '--description %(description)s '
+            f'--type {new_service_type} '
+            f'--name {new_service_name} '
+            f'--description {new_service_description} '
             '--disable '
-            '%(service)s'
-            % {
-                'type': new_service_type,
-                'name': new_service_name,
-                'description': new_service_description,
-                'service': service_name,
-            }
+            f'{service_name}'
         )
         self.assertEqual(0, len(raw_output))
         # get service details
-        raw_output = self.openstack('service show %s' % new_service_name)
+        raw_output = self.openstack(f'service show {new_service_name}')
         # assert service details
         service = self.parse_show_as_object(raw_output)
         self.assertEqual(new_service_type, service['type'])
@@ -67,6 +61,6 @@ class ServiceTests(common.IdentityTests):
 
     def test_service_show(self):
         service_name = self._create_dummy_service()
-        raw_output = self.openstack('service show %s' % service_name)
+        raw_output = self.openstack(f'service show {service_name}')
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.SERVICE_FIELDS)
diff --git a/openstackclient/tests/functional/identity/v3/test_service_provider.py b/openstackclient/tests/functional/identity/v3/test_service_provider.py
index b7ab14bc43..793223b9d9 100644
--- a/openstackclient/tests/functional/identity/v3/test_service_provider.py
+++ b/openstackclient/tests/functional/identity/v3/test_service_provider.py
@@ -24,7 +24,7 @@ class ServiceProviderTests(common.IdentityTests):
     def test_sp_delete(self):
         service_provider = self._create_dummy_sp(add_clean_up=False)
         raw_output = self.openstack(
-            'service provider delete %s' % service_provider
+            f'service provider delete {service_provider}'
         )
         self.assertEqual(0, len(raw_output))
 
@@ -37,7 +37,7 @@ class ServiceProviderTests(common.IdentityTests):
     def test_sp_show(self):
         service_provider = self._create_dummy_sp(add_clean_up=True)
         raw_output = self.openstack(
-            'service provider show %s' % service_provider
+            f'service provider show {service_provider}'
         )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.SERVICE_PROVIDER_FIELDS)
@@ -62,7 +62,7 @@ class ServiceProviderTests(common.IdentityTests):
         )
         self.assertEqual(0, len(raw_output))
         raw_output = self.openstack(
-            'service provider show %s' % service_provider
+            f'service provider show {service_provider}'
         )
         updated_value = self.parse_show_as_object(raw_output)
         self.assertIn(new_description, updated_value['description'])
diff --git a/openstackclient/tests/functional/identity/v3/test_user.py b/openstackclient/tests/functional/identity/v3/test_user.py
index 917da4a3f6..c32524600c 100644
--- a/openstackclient/tests/functional/identity/v3/test_user.py
+++ b/openstackclient/tests/functional/identity/v3/test_user.py
@@ -22,9 +22,7 @@ class UserTests(common.IdentityTests):
     def test_user_delete(self):
         username = self._create_dummy_user(add_clean_up=False)
         raw_output = self.openstack(
-            'user delete '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': username}
+            'user delete ' f'--domain {self.domain_name} ' f'{username}'
         )
         self.assertEqual(0, len(raw_output))
 
@@ -36,25 +34,19 @@ class UserTests(common.IdentityTests):
     def test_user_set(self):
         username = self._create_dummy_user()
         raw_output = self.openstack(
-            'user show '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': username}
+            'user show ' f'--domain {self.domain_name} ' f'{username}'
         )
         user = self.parse_show_as_object(raw_output)
         new_username = data_utils.rand_name('NewTestUser')
         new_email = data_utils.rand_name() + '@example.com'
         raw_output = self.openstack(
-            'user set '
-            '--email %(email)s '
-            '--name %(new_name)s '
-            '%(id)s'
-            % {'email': new_email, 'new_name': new_username, 'id': user['id']}
+            'user set ' '--email {email} ' '--name {new_name} ' '{id}'.format(
+                email=new_email, new_name=new_username, id=user['id']
+            )
         )
         self.assertEqual(0, len(raw_output))
         raw_output = self.openstack(
-            'user show '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': new_username}
+            'user show ' f'--domain {self.domain_name} ' f'{new_username}'
         )
         updated_user = self.parse_show_as_object(raw_output)
         self.assertEqual(user['id'], updated_user['id'])
@@ -65,36 +57,29 @@ class UserTests(common.IdentityTests):
         project_name = self._create_dummy_project()
         # get original user details
         raw_output = self.openstack(
-            'user show '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': username}
+            'user show ' f'--domain {self.domain_name} ' f'{username}'
         )
         user = self.parse_show_as_object(raw_output)
         # update user
         raw_output = self.openstack(
             'user set '
-            '--project %(project)s '
-            '--project-domain %(project_domain)s '
-            '%(id)s'
-            % {
-                'project': project_name,
-                'project_domain': self.domain_name,
-                'id': user['id'],
-            }
+            '--project {project} '
+            '--project-domain {project_domain} '
+            '{id}'.format(
+                project=project_name,
+                project_domain=self.domain_name,
+                id=user['id'],
+            )
         )
         self.assertEqual(0, len(raw_output))
         # get updated user details
         raw_output = self.openstack(
-            'user show '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': username}
+            'user show ' f'--domain {self.domain_name} ' f'{username}'
         )
         updated_user = self.parse_show_as_object(raw_output)
         # get project details
         raw_output = self.openstack(
-            'project show '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': project_name}
+            'project show ' f'--domain {self.domain_name} ' f'{project_name}'
         )
         project = self.parse_show_as_object(raw_output)
         # check updated user details
@@ -104,9 +89,7 @@ class UserTests(common.IdentityTests):
     def test_user_show(self):
         username = self._create_dummy_user()
         raw_output = self.openstack(
-            'user show '
-            '--domain %(domain)s '
-            '%(name)s' % {'domain': self.domain_name, 'name': username}
+            'user show ' f'--domain {self.domain_name} ' f'{username}'
         )
         items = self.parse_show(raw_output)
         self.assert_show_fields(items, self.USER_FIELDS)
diff --git a/openstackclient/tests/functional/image/v2/test_image.py b/openstackclient/tests/functional/image/v2/test_image.py
index 93251ea53b..4d51737c31 100644
--- a/openstackclient/tests/functional/image/v2/test_image.py
+++ b/openstackclient/tests/functional/image/v2/test_image.py
@@ -30,9 +30,7 @@ class ImageTests(base.BaseImageTests):
         self.image_tag = 'my_tag'
         self.image_tag1 = 'random'
         output = self.openstack(
-            'image create --tag {tag} {name}'.format(
-                tag=self.image_tag, name=self.name
-            ),
+            f'image create --tag {self.image_tag} {self.name}',
             parse_output=True,
         )
         self.image_id = output["id"]
diff --git a/openstackclient/tests/functional/network/v2/common.py b/openstackclient/tests/functional/network/v2/common.py
index f7c7212a1a..4cd14ebc76 100644
--- a/openstackclient/tests/functional/network/v2/common.py
+++ b/openstackclient/tests/functional/network/v2/common.py
@@ -80,9 +80,7 @@ class NetworkTagTests(NetworkTests):
 
     def _list_tag_check(self, project_id, expected):
         cmd_output = self.openstack(
-            '{} list --long --project {}'.format(
-                self.base_command, project_id
-            ),
+            f'{self.base_command} list --long --project {project_id}',
             parse_output=True,
         )
         for name, tags in expected:
diff --git a/openstackclient/tests/functional/network/v2/test_default_security_group_rule.py b/openstackclient/tests/functional/network/v2/test_default_security_group_rule.py
index d6ce95c1a8..1481c9a417 100644
--- a/openstackclient/tests/functional/network/v2/test_default_security_group_rule.py
+++ b/openstackclient/tests/functional/network/v2/test_default_security_group_rule.py
@@ -30,14 +30,9 @@ class SecurityGroupRuleTests(common.NetworkTests):
         # Create the default security group rule.
         cmd_output = self.openstack(
             'default security group rule create '
-            '--protocol %(protocol)s '
-            '--dst-port %(port)s:%(port)s '
-            '--%(direction)s --ethertype IPv4 '
-            % {
-                'protocol': self.protocol,
-                'port': self.port,
-                'direction': self.direction,
-            },
+            f'--protocol {self.protocol} '
+            f'--dst-port {self.port}:{self.port} '
+            f'--{self.direction} --ethertype IPv4 ',
             parse_output=True,
         )
         self.addCleanup(
diff --git a/openstackclient/tests/functional/network/v2/test_l3_conntrack_helper.py b/openstackclient/tests/functional/network/v2/test_l3_conntrack_helper.py
index 510ec8b2dd..95ebb49cea 100644
--- a/openstackclient/tests/functional/network/v2/test_l3_conntrack_helper.py
+++ b/openstackclient/tests/functional/network/v2/test_l3_conntrack_helper.py
@@ -41,15 +41,14 @@ class L3ConntrackHelperTests(common.NetworkTests):
         created_helpers = []
         for helper in helpers:
             output = self.openstack(
-                'network l3 conntrack helper create %(router)s '
-                '--helper %(helper)s --protocol %(protocol)s '
-                '--port %(port)s '
-                % {
-                    'router': router_id,
-                    'helper': helper['helper'],
-                    'protocol': helper['protocol'],
-                    'port': helper['port'],
-                },
+                'network l3 conntrack helper create {router} '
+                '--helper {helper} --protocol {protocol} '
+                '--port {port} '.format(
+                    router=router_id,
+                    helper=helper['helper'],
+                    protocol=helper['protocol'],
+                    port=helper['port'],
+                ),
                 parse_output=True,
             )
             self.assertEqual(helper['helper'], output['helper'])
@@ -70,8 +69,8 @@ class L3ConntrackHelperTests(common.NetworkTests):
         ct_ids = " ".join([ct['id'] for ct in created_helpers])
 
         raw_output = self.openstack(
-            '--debug network l3 conntrack helper delete %(router)s '
-            '%(ct_ids)s' % {'router': router_id, 'ct_ids': ct_ids}
+            f'--debug network l3 conntrack helper delete {router_id} '
+            f'{ct_ids}'
         )
         self.assertOutput('', raw_output)
 
@@ -87,7 +86,7 @@ class L3ConntrackHelperTests(common.NetworkTests):
         router_id = self._create_router()
         self._create_helpers(router_id, helpers)
         output = self.openstack(
-            'network l3 conntrack helper list %s ' % router_id,
+            f'network l3 conntrack helper list {router_id} ',
             parse_output=True,
         )
         for ct in output:
@@ -100,12 +99,11 @@ class L3ConntrackHelperTests(common.NetworkTests):
         router_id = self._create_router()
         created_helper = self._create_helpers(router_id, [helper])[0]
         output = self.openstack(
-            'network l3 conntrack helper show %(router_id)s %(ct_id)s '
-            '-f json'
-            % {
-                'router_id': router_id,
-                'ct_id': created_helper['id'],
-            },
+            'network l3 conntrack helper show {router_id} {ct_id} '
+            '-f json'.format(
+                router_id=router_id,
+                ct_id=created_helper['id'],
+            ),
             parse_output=True,
         )
         self.assertEqual(helper['helper'], output['helper'])
@@ -113,23 +111,21 @@ class L3ConntrackHelperTests(common.NetworkTests):
         self.assertEqual(helper['port'], output['port'])
 
         raw_output = self.openstack(
-            'network l3 conntrack helper set %(router_id)s %(ct_id)s '
-            '--port %(port)s '
-            % {
-                'router_id': router_id,
-                'ct_id': created_helper['id'],
-                'port': helper['port'] + 1,
-            }
+            'network l3 conntrack helper set {router_id} {ct_id} '
+            '--port {port} '.format(
+                router_id=router_id,
+                ct_id=created_helper['id'],
+                port=helper['port'] + 1,
+            )
         )
         self.assertOutput('', raw_output)
 
         output = self.openstack(
-            'network l3 conntrack helper show %(router_id)s %(ct_id)s '
-            '-f json'
-            % {
-                'router_id': router_id,
-                'ct_id': created_helper['id'],
-            },
+            'network l3 conntrack helper show {router_id} {ct_id} '
+            '-f json'.format(
+                router_id=router_id,
+                ct_id=created_helper['id'],
+            ),
             parse_output=True,
         )
         self.assertEqual(helper['port'] + 1, output['port'])
diff --git a/openstackclient/tests/functional/network/v2/test_network.py b/openstackclient/tests/functional/network/v2/test_network.py
index 8dbe883b6c..a38d88bdac 100644
--- a/openstackclient/tests/functional/network/v2/test_network.py
+++ b/openstackclient/tests/functional/network/v2/test_network.py
@@ -206,7 +206,7 @@ class NetworkTests(common.NetworkTagTests):
             'network create ' + network_options + name1,
             parse_output=True,
         )
-        self.addCleanup(self.openstack, 'network delete %s' % name1)
+        self.addCleanup(self.openstack, f'network delete {name1}')
         self.assertIsNotNone(cmd_output["id"])
         if self.haz_network:
             self.assertEqual(
@@ -342,33 +342,30 @@ class NetworkTests(common.NetworkTagTests):
 
         name1 = uuid.uuid4().hex
         cmd_output = self.openstack(
-            'network create --description aaaa %s' % name1,
+            f'network create --description aaaa {name1}',
             parse_output=True,
         )
 
-        self.addCleanup(self.openstack, 'network delete %s' % name1)
+        self.addCleanup(self.openstack, f'network delete {name1}')
 
         # Get network ID
         network_id = cmd_output['id']
 
         # Add Agent to Network
         self.openstack(
-            'network agent add network --dhcp {} {}'.format(
-                agent_id, network_id
-            )
+            f'network agent add network --dhcp {agent_id} {network_id}'
         )
 
         # Test network list --agent
         cmd_output = self.openstack(
-            'network list --agent %s' % agent_id,
+            f'network list --agent {agent_id}',
             parse_output=True,
         )
 
         # Cleanup
         # Remove Agent from Network
         self.openstack(
-            'network agent remove network --dhcp %s %s'
-            % (agent_id, network_id)
+            f'network agent remove network --dhcp {agent_id} {network_id}'
         )
 
         # Assert
@@ -388,10 +385,10 @@ class NetworkTests(common.NetworkTagTests):
             '--no-share '
             '--internal '
             '--no-default '
-            '--enable-port-security %s' % name,
+            f'--enable-port-security {name}',
             parse_output=True,
         )
-        self.addCleanup(self.openstack, 'network delete %s' % name)
+        self.addCleanup(self.openstack, f'network delete {name}')
         self.assertIsNotNone(cmd_output["id"])
         self.assertEqual(
             'aaaa',
@@ -416,7 +413,7 @@ class NetworkTests(common.NetworkTagTests):
             '--disable '
             '--share '
             '--external '
-            '--disable-port-security %s' % name
+            f'--disable-port-security {name}'
         )
         self.assertOutput('', raw_output)
 
diff --git a/openstackclient/tests/functional/network/v2/test_network_agent.py b/openstackclient/tests/functional/network/v2/test_network_agent.py
index bbe168aeed..013201a40e 100644
--- a/openstackclient/tests/functional/network/v2/test_network_agent.py
+++ b/openstackclient/tests/functional/network/v2/test_network_agent.py
@@ -42,7 +42,7 @@ class TestAgent(common.NetworkTests):
 
         # agent show
         cmd_output = self.openstack(
-            'network agent show %s' % agent_ids[0],
+            f'network agent show {agent_ids[0]}',
             parse_output=True,
         )
         self.assertEqual(
@@ -57,12 +57,12 @@ class TestAgent(common.NetworkTests):
 
         # agent set
         raw_output = self.openstack(
-            'network agent set --disable %s' % agent_ids[0]
+            f'network agent set --disable {agent_ids[0]}'
         )
         self.assertOutput('', raw_output)
 
         cmd_output = self.openstack(
-            'network agent show %s' % agent_ids[0],
+            f'network agent show {agent_ids[0]}',
             parse_output=True,
         )
         self.assertEqual(
@@ -71,12 +71,12 @@ class TestAgent(common.NetworkTests):
         )
 
         raw_output = self.openstack(
-            'network agent set --enable %s' % agent_ids[0]
+            f'network agent set --enable {agent_ids[0]}'
         )
         self.assertOutput('', raw_output)
 
         cmd_output = self.openstack(
-            'network agent show %s' % agent_ids[0],
+            f'network agent show {agent_ids[0]}',
             parse_output=True,
         )
         self.assertEqual(
@@ -112,33 +112,30 @@ class TestAgentList(common.NetworkTests):
 
         name1 = uuid.uuid4().hex
         cmd_output = self.openstack(
-            'network create --description aaaa %s' % name1,
+            f'network create --description aaaa {name1}',
             parse_output=True,
         )
 
-        self.addCleanup(self.openstack, 'network delete %s' % name1)
+        self.addCleanup(self.openstack, f'network delete {name1}')
 
         # Get network ID
         network_id = cmd_output['id']
 
         # Add Agent to Network
         self.openstack(
-            'network agent add network --dhcp {} {}'.format(
-                agent_id, network_id
-            )
+            f'network agent add network --dhcp {agent_id} {network_id}'
         )
 
         # Test network agent list --network
         cmd_output = self.openstack(
-            'network agent list --network %s' % network_id,
+            f'network agent list --network {network_id}',
             parse_output=True,
         )
 
         # Cleanup
         # Remove Agent from Network
         self.openstack(
-            'network agent remove network --dhcp %s %s'
-            % (agent_id, network_id)
+            f'network agent remove network --dhcp {agent_id} {network_id}'
         )
 
         # Assert
@@ -153,11 +150,11 @@ class TestAgentList(common.NetworkTests):
 
         name = uuid.uuid4().hex
         cmd_output = self.openstack(
-            'router create %s' % name,
+            f'router create {name}',
             parse_output=True,
         )
 
-        self.addCleanup(self.openstack, 'router delete %s' % name)
+        self.addCleanup(self.openstack, f'router delete {name}')
         # Get router ID
         router_id = cmd_output['id']
         # Get l3 agent id
@@ -175,7 +172,7 @@ class TestAgentList(common.NetworkTests):
 
         # Test router list --agent
         cmd_output = self.openstack(
-            'network agent list --router %s' % router_id,
+            f'network agent list --router {router_id}',
             parse_output=True,
         )
 
@@ -184,12 +181,10 @@ class TestAgentList(common.NetworkTests):
 
         # Remove router from agent
         self.openstack(
-            'network agent remove router --l3 {} {}'.format(
-                agent_id, router_id
-            )
+            f'network agent remove router --l3 {agent_id} {router_id}'
         )
         cmd_output = self.openstack(
-            'network agent list --router %s' % router_id,
+            f'network agent list --router {router_id}',
             parse_output=True,
         )
         agent_ids = [x['ID'] for x in cmd_output]
diff --git a/openstackclient/tests/functional/network/v2/test_network_flavor.py b/openstackclient/tests/functional/network/v2/test_network_flavor.py
index e04d10e805..2b88670378 100644
--- a/openstackclient/tests/functional/network/v2/test_network_flavor.py
+++ b/openstackclient/tests/functional/network/v2/test_network_flavor.py
@@ -37,10 +37,10 @@ class NetworkFlavorTests(common.NetworkTests):
         )
         service_profile_id = cmd_output2.get('id')
 
-        self.addCleanup(self.openstack, 'network flavor delete %s' % flavor_id)
+        self.addCleanup(self.openstack, f'network flavor delete {flavor_id}')
         self.addCleanup(
             self.openstack,
-            'network flavor profile delete %s' % service_profile_id,
+            f'network flavor profile delete {service_profile_id}',
         )
         # Add flavor to service profile
         self.openstack(
diff --git a/openstackclient/tests/functional/network/v2/test_network_ndp_proxy.py b/openstackclient/tests/functional/network/v2/test_network_ndp_proxy.py
index d22f297470..11d121a3e8 100644
--- a/openstackclient/tests/functional/network/v2/test_network_ndp_proxy.py
+++ b/openstackclient/tests/functional/network/v2/test_network_ndp_proxy.py
@@ -31,20 +31,15 @@ class L3NDPProxyTests(common.NetworkTests):
         self.created_ndp_proxies = []
 
         json_output = self.openstack(
-            'address scope create --ip-version 6 '
-            '%(address_s_name)s' % {'address_s_name': self.ADDR_SCOPE_NAME},
+            'address scope create --ip-version 6 ' f'{self.ADDR_SCOPE_NAME}',
             parse_output=True,
         )
         self.assertIsNotNone(json_output['id'])
         self.ADDRESS_SCOPE_ID = json_output['id']
         json_output = self.openstack(
-            'subnet pool create %(subnet_p_name)s '
-            '--address-scope %(address_scope)s '
-            '--pool-prefix 2001:db8::/96 --default-prefix-length 112'
-            % {
-                'subnet_p_name': self.SUBNET_P_NAME,
-                'address_scope': self.ADDRESS_SCOPE_ID,
-            },
+            f'subnet pool create {self.SUBNET_P_NAME} '
+            f'--address-scope {self.ADDRESS_SCOPE_ID} '
+            '--pool-prefix 2001:db8::/96 --default-prefix-length 112',
             parse_output=True,
         )
         self.assertIsNotNone(json_output['id'])
@@ -57,12 +52,7 @@ class L3NDPProxyTests(common.NetworkTests):
         self.EXT_NET_ID = json_output['id']
         json_output = self.openstack(
             'subnet create --ip-version 6 --subnet-pool '
-            '%(subnet_pool)s --network %(net_id)s %(sub_name)s'
-            % {
-                'subnet_pool': self.SUBNET_POOL_ID,
-                'net_id': self.EXT_NET_ID,
-                'sub_name': self.EXT_SUB_NAME,
-            },
+            f'{self.SUBNET_POOL_ID} --network {self.EXT_NET_ID} {self.EXT_SUB_NAME}',
             parse_output=True,
         )
         self.assertIsNotNone(json_output['id'])
@@ -74,8 +64,7 @@ class L3NDPProxyTests(common.NetworkTests):
         self.assertIsNotNone(json_output['id'])
         self.ROT_ID = json_output['id']
         output = self.openstack(
-            'router set %(router_id)s --external-gateway %(net_id)s'
-            % {'router_id': self.ROT_ID, 'net_id': self.EXT_NET_ID}
+            f'router set {self.ROT_ID} --external-gateway {self.EXT_NET_ID}'
         )
         self.assertEqual('', output)
         output = self.openstack('router set --enable-ndp-proxy ' + self.ROT_ID)
@@ -93,23 +82,14 @@ class L3NDPProxyTests(common.NetworkTests):
         self.INT_NET_ID = json_output['id']
         json_output = self.openstack(
             'subnet create --ip-version 6 --subnet-pool '
-            '%(subnet_pool)s --network %(net_id)s %(sub_name)s'
-            % {
-                'subnet_pool': self.SUBNET_POOL_ID,
-                'net_id': self.INT_NET_ID,
-                'sub_name': self.INT_SUB_NAME,
-            },
+            f'{self.SUBNET_POOL_ID} --network {self.INT_NET_ID} {self.INT_SUB_NAME}',
             parse_output=True,
         )
         self.assertIsNotNone(json_output['id'])
         self.INT_SUB_ID = json_output['id']
         json_output = self.openstack(
-            'port create --network %(net_id)s '
-            '%(port_name)s'
-            % {
-                'net_id': self.INT_NET_ID,
-                'port_name': self.INT_PORT_NAME,
-            },
+            f'port create --network {self.INT_NET_ID} '
+            f'{self.INT_PORT_NAME}',
             parse_output=True,
         )
         self.assertIsNotNone(json_output['id'])
@@ -161,14 +141,13 @@ class L3NDPProxyTests(common.NetworkTests):
     def _create_ndp_proxies(self, ndp_proxies):
         for ndp_proxy in ndp_proxies:
             output = self.openstack(
-                'router ndp proxy create %(router)s --name %(name)s '
-                '--port %(port)s --ip-address %(address)s'
-                % {
-                    'router': ndp_proxy['router_id'],
-                    'name': ndp_proxy['name'],
-                    'port': ndp_proxy['port_id'],
-                    'address': ndp_proxy['address'],
-                },
+                'router ndp proxy create {router} --name {name} '
+                '--port {port} --ip-address {address}'.format(
+                    router=ndp_proxy['router_id'],
+                    name=ndp_proxy['name'],
+                    port=ndp_proxy['port_id'],
+                    address=ndp_proxy['address'],
+                ),
                 parse_output=True,
             )
             self.assertEqual(ndp_proxy['router_id'], output['router_id'])
@@ -214,8 +193,7 @@ class L3NDPProxyTests(common.NetworkTests):
         self._create_ndp_proxies([ndp_proxies])
         ndp_proxy_id = self.created_ndp_proxies[0]['id']
         output = self.openstack(
-            'router ndp proxy set --description %s %s'
-            % (description, ndp_proxy_id)
+            f'router ndp proxy set --description {description} {ndp_proxy_id}'
         )
         self.assertEqual('', output)
         json_output = self.openstack(
diff --git a/openstackclient/tests/functional/network/v2/test_network_qos_rule.py b/openstackclient/tests/functional/network/v2/test_network_qos_rule.py
index 8db484e2e2..28c38e5a45 100644
--- a/openstackclient/tests/functional/network/v2/test_network_qos_rule.py
+++ b/openstackclient/tests/functional/network/v2/test_network_qos_rule.py
@@ -32,40 +32,39 @@ class NetworkQosRuleTestsMinimumBandwidth(NetworkQosTests):
     def setUp(self):
         super().setUp()
 
-        self.QOS_POLICY_NAME = 'qos_policy_%s' % uuid.uuid4().hex
+        self.QOS_POLICY_NAME = f'qos_policy_{uuid.uuid4().hex}'
 
-        self.openstack('network qos policy create %s' % self.QOS_POLICY_NAME)
+        self.openstack(f'network qos policy create {self.QOS_POLICY_NAME}')
         self.addCleanup(
             self.openstack,
-            'network qos policy delete %s' % self.QOS_POLICY_NAME,
+            f'network qos policy delete {self.QOS_POLICY_NAME}',
         )
         cmd_output = self.openstack(
             'network qos rule create '
             '--type minimum-bandwidth '
             '--min-kbps 2800 '
-            '--egress %s' % self.QOS_POLICY_NAME,
+            f'--egress {self.QOS_POLICY_NAME}',
             parse_output=True,
         )
         self.RULE_ID = cmd_output['id']
         self.addCleanup(
             self.openstack,
-            'network qos rule delete %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule delete {self.QOS_POLICY_NAME} {self.RULE_ID}',
         )
         self.assertTrue(self.RULE_ID)
 
     def test_qos_rule_create_delete(self):
         # This is to check the output of qos rule delete
         policy_name = uuid.uuid4().hex
-        self.openstack('network qos policy create %s' % policy_name)
+        self.openstack(f'network qos policy create {policy_name}')
         self.addCleanup(
-            self.openstack, 'network qos policy delete %s' % policy_name
+            self.openstack, f'network qos policy delete {policy_name}'
         )
         rule = self.openstack(
             'network qos rule create '
             '--type minimum-bandwidth '
             '--min-kbps 2800 '
-            '--egress %s' % policy_name,
+            f'--egress {policy_name}',
             parse_output=True,
         )
         raw_output = self.openstack(
@@ -75,27 +74,24 @@ class NetworkQosRuleTestsMinimumBandwidth(NetworkQosTests):
 
     def test_qos_rule_list(self):
         cmd_output = self.openstack(
-            'network qos rule list %s' % self.QOS_POLICY_NAME,
+            f'network qos rule list {self.QOS_POLICY_NAME}',
             parse_output=True,
         )
         self.assertIn(self.RULE_ID, [rule['ID'] for rule in cmd_output])
 
     def test_qos_rule_show(self):
         cmd_output = self.openstack(
-            'network qos rule show %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule show {self.QOS_POLICY_NAME} {self.RULE_ID}',
             parse_output=True,
         )
         self.assertEqual(self.RULE_ID, cmd_output['id'])
 
     def test_qos_rule_set(self):
         self.openstack(
-            'network qos rule set --min-kbps 7500 %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID)
+            f'network qos rule set --min-kbps 7500 {self.QOS_POLICY_NAME} {self.RULE_ID}'
         )
         cmd_output = self.openstack(
-            'network qos rule show %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule show {self.QOS_POLICY_NAME} {self.RULE_ID}',
             parse_output=True,
         )
         self.assertEqual(7500, cmd_output['min_kbps'])
@@ -107,40 +103,39 @@ class NetworkQosRuleTestsMinimumPacketRate(NetworkQosTests):
     def setUp(self):
         super().setUp()
 
-        self.QOS_POLICY_NAME = 'qos_policy_%s' % uuid.uuid4().hex
+        self.QOS_POLICY_NAME = f'qos_policy_{uuid.uuid4().hex}'
 
-        self.openstack('network qos policy create %s' % self.QOS_POLICY_NAME)
+        self.openstack(f'network qos policy create {self.QOS_POLICY_NAME}')
         self.addCleanup(
             self.openstack,
-            'network qos policy delete %s' % self.QOS_POLICY_NAME,
+            f'network qos policy delete {self.QOS_POLICY_NAME}',
         )
         cmd_output = self.openstack(
             'network qos rule create '
             '--type minimum-packet-rate '
             '--min-kpps 2800 '
-            '--egress %s' % self.QOS_POLICY_NAME,
+            f'--egress {self.QOS_POLICY_NAME}',
             parse_output=True,
         )
         self.RULE_ID = cmd_output['id']
         self.addCleanup(
             self.openstack,
-            'network qos rule delete %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule delete {self.QOS_POLICY_NAME} {self.RULE_ID}',
         )
         self.assertTrue(self.RULE_ID)
 
     def test_qos_rule_create_delete(self):
         # This is to check the output of qos rule delete
         policy_name = uuid.uuid4().hex
-        self.openstack('network qos policy create %s' % policy_name)
+        self.openstack(f'network qos policy create {policy_name}')
         self.addCleanup(
-            self.openstack, 'network qos policy delete %s' % policy_name
+            self.openstack, f'network qos policy delete {policy_name}'
         )
         rule = self.openstack(
             'network qos rule create '
             '--type minimum-packet-rate '
             '--min-kpps 2800 '
-            '--egress %s' % policy_name,
+            f'--egress {policy_name}',
             parse_output=True,
         )
         raw_output = self.openstack(
@@ -150,27 +145,24 @@ class NetworkQosRuleTestsMinimumPacketRate(NetworkQosTests):
 
     def test_qos_rule_list(self):
         cmd_output = self.openstack(
-            'network qos rule list %s' % self.QOS_POLICY_NAME,
+            f'network qos rule list {self.QOS_POLICY_NAME}',
             parse_output=True,
         )
         self.assertIn(self.RULE_ID, [rule['ID'] for rule in cmd_output])
 
     def test_qos_rule_show(self):
         cmd_output = self.openstack(
-            'network qos rule show %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule show {self.QOS_POLICY_NAME} {self.RULE_ID}',
             parse_output=True,
         )
         self.assertEqual(self.RULE_ID, cmd_output['id'])
 
     def test_qos_rule_set(self):
         self.openstack(
-            'network qos rule set --min-kpps 7500 --any %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID)
+            f'network qos rule set --min-kpps 7500 --any {self.QOS_POLICY_NAME} {self.RULE_ID}'
         )
         cmd_output = self.openstack(
-            'network qos rule show %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule show {self.QOS_POLICY_NAME} {self.RULE_ID}',
             parse_output=True,
         )
         self.assertEqual(7500, cmd_output['min_kpps'])
@@ -183,37 +175,36 @@ class NetworkQosRuleTestsDSCPMarking(NetworkQosTests):
     def setUp(self):
         super().setUp()
 
-        self.QOS_POLICY_NAME = 'qos_policy_%s' % uuid.uuid4().hex
-        self.openstack('network qos policy create %s' % self.QOS_POLICY_NAME)
+        self.QOS_POLICY_NAME = f'qos_policy_{uuid.uuid4().hex}'
+        self.openstack(f'network qos policy create {self.QOS_POLICY_NAME}')
         self.addCleanup(
             self.openstack,
-            'network qos policy delete %s' % self.QOS_POLICY_NAME,
+            f'network qos policy delete {self.QOS_POLICY_NAME}',
         )
         cmd_output = self.openstack(
             'network qos rule create '
             '--type dscp-marking '
-            '--dscp-mark 8 %s' % self.QOS_POLICY_NAME,
+            f'--dscp-mark 8 {self.QOS_POLICY_NAME}',
             parse_output=True,
         )
         self.RULE_ID = cmd_output['id']
         self.addCleanup(
             self.openstack,
-            'network qos rule delete %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule delete {self.QOS_POLICY_NAME} {self.RULE_ID}',
         )
         self.assertTrue(self.RULE_ID)
 
     def test_qos_rule_create_delete(self):
         # This is to check the output of qos rule delete
         policy_name = uuid.uuid4().hex
-        self.openstack('network qos policy create %s' % policy_name)
+        self.openstack(f'network qos policy create {policy_name}')
         self.addCleanup(
-            self.openstack, 'network qos policy delete %s' % policy_name
+            self.openstack, f'network qos policy delete {policy_name}'
         )
         rule = self.openstack(
             'network qos rule create '
             '--type dscp-marking '
-            '--dscp-mark 8 %s' % policy_name,
+            f'--dscp-mark 8 {policy_name}',
             parse_output=True,
         )
         raw_output = self.openstack(
@@ -223,27 +214,24 @@ class NetworkQosRuleTestsDSCPMarking(NetworkQosTests):
 
     def test_qos_rule_list(self):
         cmd_output = self.openstack(
-            'network qos rule list %s' % self.QOS_POLICY_NAME,
+            f'network qos rule list {self.QOS_POLICY_NAME}',
             parse_output=True,
         )
         self.assertIn(self.RULE_ID, [rule['ID'] for rule in cmd_output])
 
     def test_qos_rule_show(self):
         cmd_output = self.openstack(
-            'network qos rule show %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule show {self.QOS_POLICY_NAME} {self.RULE_ID}',
             parse_output=True,
         )
         self.assertEqual(self.RULE_ID, cmd_output['id'])
 
     def test_qos_rule_set(self):
         self.openstack(
-            'network qos rule set --dscp-mark 32 %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID)
+            f'network qos rule set --dscp-mark 32 {self.QOS_POLICY_NAME} {self.RULE_ID}'
         )
         cmd_output = self.openstack(
-            'network qos rule show %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule show {self.QOS_POLICY_NAME} {self.RULE_ID}',
             parse_output=True,
         )
         self.assertEqual(32, cmd_output['dscp_mark'])
@@ -255,40 +243,39 @@ class NetworkQosRuleTestsBandwidthLimit(NetworkQosTests):
     def setUp(self):
         super().setUp()
 
-        self.QOS_POLICY_NAME = 'qos_policy_%s' % uuid.uuid4().hex
-        self.openstack('network qos policy create %s' % self.QOS_POLICY_NAME)
+        self.QOS_POLICY_NAME = f'qos_policy_{uuid.uuid4().hex}'
+        self.openstack(f'network qos policy create {self.QOS_POLICY_NAME}')
         self.addCleanup(
             self.openstack,
-            'network qos policy delete %s' % self.QOS_POLICY_NAME,
+            f'network qos policy delete {self.QOS_POLICY_NAME}',
         )
         cmd_output = self.openstack(
             'network qos rule create '
             '--type bandwidth-limit '
             '--max-kbps 10000 '
-            '--egress %s' % self.QOS_POLICY_NAME,
+            f'--egress {self.QOS_POLICY_NAME}',
             parse_output=True,
         )
         self.RULE_ID = cmd_output['id']
         self.addCleanup(
             self.openstack,
-            'network qos rule delete %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule delete {self.QOS_POLICY_NAME} {self.RULE_ID}',
         )
         self.assertTrue(self.RULE_ID)
 
     def test_qos_rule_create_delete(self):
         # This is to check the output of qos rule delete
         policy_name = uuid.uuid4().hex
-        self.openstack('network qos policy create %s' % policy_name)
+        self.openstack(f'network qos policy create {policy_name}')
         self.addCleanup(
-            self.openstack, 'network qos policy delete %s' % policy_name
+            self.openstack, f'network qos policy delete {policy_name}'
         )
         rule = self.openstack(
             'network qos rule create '
             '--type bandwidth-limit '
             '--max-kbps 10000 '
             '--max-burst-kbits 1400 '
-            '--egress %s' % policy_name,
+            f'--egress {policy_name}',
             parse_output=True,
         )
         raw_output = self.openstack(
@@ -298,15 +285,14 @@ class NetworkQosRuleTestsBandwidthLimit(NetworkQosTests):
 
     def test_qos_rule_list(self):
         cmd_output = self.openstack(
-            'network qos rule list %s' % self.QOS_POLICY_NAME,
+            f'network qos rule list {self.QOS_POLICY_NAME}',
             parse_output=True,
         )
         self.assertIn(self.RULE_ID, [rule['ID'] for rule in cmd_output])
 
     def test_qos_rule_show(self):
         cmd_output = self.openstack(
-            'network qos rule show %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule show {self.QOS_POLICY_NAME} {self.RULE_ID}',
             parse_output=True,
         )
         self.assertEqual(self.RULE_ID, cmd_output['id'])
@@ -315,11 +301,10 @@ class NetworkQosRuleTestsBandwidthLimit(NetworkQosTests):
         self.openstack(
             'network qos rule set --max-kbps 15000 '
             '--max-burst-kbits 1800 '
-            '--ingress %s %s' % (self.QOS_POLICY_NAME, self.RULE_ID)
+            f'--ingress {self.QOS_POLICY_NAME} {self.RULE_ID}'
         )
         cmd_output = self.openstack(
-            'network qos rule show %s %s'
-            % (self.QOS_POLICY_NAME, self.RULE_ID),
+            f'network qos rule show {self.QOS_POLICY_NAME} {self.RULE_ID}',
             parse_output=True,
         )
         self.assertEqual(15000, cmd_output['max_kbps'])
diff --git a/openstackclient/tests/functional/network/v2/test_network_qos_rule_type.py b/openstackclient/tests/functional/network/v2/test_network_qos_rule_type.py
index 77ce35716b..745191b8cb 100644
--- a/openstackclient/tests/functional/network/v2/test_network_qos_rule_type.py
+++ b/openstackclient/tests/functional/network/v2/test_network_qos_rule_type.py
@@ -67,7 +67,7 @@ class NetworkQosRuleTypeTests(common.NetworkTests):
     def test_qos_rule_type_details(self):
         for rule_type in self.AVAILABLE_RULE_TYPES:
             cmd_output = self.openstack(
-                'network qos rule type show %s -f json' % rule_type,
+                f'network qos rule type show {rule_type} -f json',
                 parse_output=True,
             )
             self.assertEqual(rule_type, cmd_output['rule_type_name'])
diff --git a/openstackclient/tests/functional/network/v2/test_network_segment_range.py b/openstackclient/tests/functional/network/v2/test_network_segment_range.py
index 604ee3cfab..3f07948b5c 100644
--- a/openstackclient/tests/functional/network/v2/test_network_segment_range.py
+++ b/openstackclient/tests/functional/network/v2/test_network_segment_range.py
@@ -128,8 +128,8 @@ class NetworkSegmentRangeTests(common.NetworkTests):
         new_minimum = 2020
         new_maximum = 2029
         cmd_output = self.openstack(
-            'network segment range set --minimum {min} --maximum {max} '
-            '{name}'.format(min=new_minimum, max=new_maximum, name=name)
+            f'network segment range set --minimum {new_minimum} --maximum {new_maximum} '
+            f'{name}'
         )
         self.assertOutput('', cmd_output)
 
diff --git a/openstackclient/tests/functional/network/v2/test_network_trunk.py b/openstackclient/tests/functional/network/v2/test_network_trunk.py
index 7c504286d7..0232943b31 100644
--- a/openstackclient/tests/functional/network/v2/test_network_trunk.py
+++ b/openstackclient/tests/functional/network/v2/test_network_trunk.py
@@ -32,33 +32,27 @@ class NetworkTrunkTests(common.NetworkTests):
         self.parent_port_name = uuid.uuid4().hex
         self.sub_port_name = uuid.uuid4().hex
 
-        self.openstack('network create %s' % network_name)
-        self.addCleanup(self.openstack, 'network delete %s' % network_name)
+        self.openstack(f'network create {network_name}')
+        self.addCleanup(self.openstack, f'network delete {network_name}')
 
         self.openstack(
-            'subnet create %s '
-            '--network %s --subnet-range 10.0.0.0/24'
-            % (subnet_name, network_name)
+            f'subnet create {subnet_name} '
+            f'--network {network_name} --subnet-range 10.0.0.0/24'
         )
         self.openstack(
-            'port create %s --network %s'
-            % (self.parent_port_name, network_name)
-        )
-        self.addCleanup(
-            self.openstack, 'port delete %s' % self.parent_port_name
+            f'port create {self.parent_port_name} --network {network_name}'
         )
+        self.addCleanup(self.openstack, f'port delete {self.parent_port_name}')
         json_out = self.openstack(
-            'port create %s --network %s -f json'
-            % (self.sub_port_name, network_name)
+            f'port create {self.sub_port_name} --network {network_name} -f json'
         )
         self.sub_port_id = json.loads(json_out)['id']
-        self.addCleanup(self.openstack, 'port delete %s' % self.sub_port_name)
+        self.addCleanup(self.openstack, f'port delete {self.sub_port_name}')
 
     def test_network_trunk_create_delete(self):
         trunk_name = uuid.uuid4().hex
         self.openstack(
-            'network trunk create %s --parent-port %s -f json '
-            % (trunk_name, self.parent_port_name)
+            f'network trunk create {trunk_name} --parent-port {self.parent_port_name} -f json '
         )
         raw_output = self.openstack('network trunk delete ' + trunk_name)
         self.assertEqual('', raw_output)
@@ -67,8 +61,7 @@ class NetworkTrunkTests(common.NetworkTests):
         trunk_name = uuid.uuid4().hex
         json_output = json.loads(
             self.openstack(
-                'network trunk create %s --parent-port %s -f json '
-                % (trunk_name, self.parent_port_name)
+                f'network trunk create {trunk_name} --parent-port {self.parent_port_name} -f json '
             )
         )
         self.addCleanup(self.openstack, 'network trunk delete ' + trunk_name)
@@ -81,8 +74,7 @@ class NetworkTrunkTests(common.NetworkTests):
         trunk_name = uuid.uuid4().hex
         json_output = json.loads(
             self.openstack(
-                'network trunk create %s --parent-port %s -f json '
-                % (trunk_name, self.parent_port_name)
+                f'network trunk create {trunk_name} --parent-port {self.parent_port_name} -f json '
             )
         )
         self.addCleanup(self.openstack, 'network trunk delete ' + trunk_name)
@@ -98,8 +90,7 @@ class NetworkTrunkTests(common.NetworkTests):
         # Add subport to trunk
         self.openstack(
             'network trunk set '
-            + '--subport port=%s,segmentation-type=vlan,segmentation-id=42 '
-            % (self.sub_port_name)
+            + f'--subport port={self.sub_port_name},segmentation-type=vlan,segmentation-id=42 '
             + trunk_name
         )
         json_output = json.loads(
@@ -132,10 +123,9 @@ class NetworkTrunkTests(common.NetworkTests):
         trunk_name = uuid.uuid4().hex
         json_output = json.loads(
             self.openstack(
-                'network trunk create %s --parent-port %s '
-                '--subport port=%s,segmentation-type=vlan,segmentation-id=42 '
+                f'network trunk create {trunk_name} --parent-port {self.parent_port_name} '
+                f'--subport port={self.sub_port_name},segmentation-type=vlan,segmentation-id=42 '
                 '-f json '
-                % (trunk_name, self.parent_port_name, self.sub_port_name)
             )
         )
         self.addCleanup(self.openstack, 'network trunk delete ' + trunk_name)
@@ -143,7 +133,7 @@ class NetworkTrunkTests(common.NetworkTests):
 
         json_output = json.loads(
             self.openstack(
-                'network subport list --trunk %s -f json' % trunk_name
+                f'network subport list --trunk {trunk_name} -f json'
             )
         )
         self.assertEqual(
diff --git a/openstackclient/tests/functional/network/v2/test_port.py b/openstackclient/tests/functional/network/v2/test_port.py
index 0ba3773417..24fbe0ea16 100644
--- a/openstackclient/tests/functional/network/v2/test_port.py
+++ b/openstackclient/tests/functional/network/v2/test_port.py
@@ -31,14 +31,14 @@ class PortTests(common.NetworkTagTests):
             cls.NETWORK_NAME = uuid.uuid4().hex
 
             # Create a network for the port tests
-            cls.openstack('network create %s' % cls.NETWORK_NAME)
+            cls.openstack(f'network create {cls.NETWORK_NAME}')
 
     @classmethod
     def tearDownClass(cls):
         try:
             if cls.haz_network:
                 raw_output = cls.openstack(
-                    'network delete %s' % cls.NETWORK_NAME
+                    f'network delete {cls.NETWORK_NAME}'
                 )
                 cls.assertOutput('', raw_output)
         finally:
@@ -56,9 +56,7 @@ class PortTests(common.NetworkTagTests):
         self.assertEqual(self.NAME, json_output.get('name'))
 
         json_output = self.openstack(
-            'port create --network {} {}x'.format(
-                self.NETWORK_NAME, self.NAME
-            ),
+            f'port create --network {self.NETWORK_NAME} {self.NAME}x',
             parse_output=True,
         )
         id2 = json_output.get('id')
@@ -80,20 +78,18 @@ class PortTests(common.NetworkTagTests):
         self.assertIsNotNone(id1)
         mac1 = json_output.get('mac_address')
         self.assertIsNotNone(mac1)
-        self.addCleanup(self.openstack, 'port delete %s' % id1)
+        self.addCleanup(self.openstack, f'port delete {id1}')
         self.assertEqual(self.NAME, json_output.get('name'))
 
         json_output = self.openstack(
-            'port create --network {} {}x'.format(
-                self.NETWORK_NAME, self.NAME
-            ),
+            f'port create --network {self.NETWORK_NAME} {self.NAME}x',
             parse_output=True,
         )
         id2 = json_output.get('id')
         self.assertIsNotNone(id2)
         mac2 = json_output.get('mac_address')
         self.assertIsNotNone(mac2)
-        self.addCleanup(self.openstack, 'port delete %s' % id2)
+        self.addCleanup(self.openstack, f'port delete {id2}')
         self.assertEqual(self.NAME + 'x', json_output.get('name'))
 
         # Test list
@@ -120,7 +116,7 @@ class PortTests(common.NetworkTagTests):
 
         # Test list --mac-address
         json_output = self.openstack(
-            'port list --mac-address %s' % mac2,
+            f'port list --mac-address {mac2}',
             parse_output=True,
         )
         item_map = {
@@ -147,22 +143,22 @@ class PortTests(common.NetworkTagTests):
         name = uuid.uuid4().hex
         json_output = self.openstack(
             'port create '
-            '--network %s '
+            f'--network {self.NETWORK_NAME} '
             '--description xyzpdq '
-            '--disable %s' % (self.NETWORK_NAME, name),
+            f'--disable {name}',
             parse_output=True,
         )
         id1 = json_output.get('id')
-        self.addCleanup(self.openstack, 'port delete %s' % id1)
+        self.addCleanup(self.openstack, f'port delete {id1}')
         self.assertEqual(name, json_output.get('name'))
         self.assertEqual('xyzpdq', json_output.get('description'))
         self.assertEqual(False, json_output.get('admin_state_up'))
 
-        raw_output = self.openstack('port set --enable %s' % name)
+        raw_output = self.openstack(f'port set --enable {name}')
         self.assertOutput('', raw_output)
 
         json_output = self.openstack(
-            'port show %s' % name,
+            f'port show {name}',
             parse_output=True,
         )
         sg_id = json_output.get('security_group_ids')[0]
@@ -178,7 +174,7 @@ class PortTests(common.NetworkTagTests):
         self.assertOutput('', raw_output)
 
         json_output = self.openstack(
-            'port show %s' % name,
+            f'port show {name}',
             parse_output=True,
         )
         self.assertEqual([], json_output.get('security_group_ids'))
@@ -186,19 +182,19 @@ class PortTests(common.NetworkTagTests):
     def test_port_admin_set(self):
         """Test create, set (as admin), show, delete"""
         json_output = self.openstack(
-            'port create ' '--network %s %s' % (self.NETWORK_NAME, self.NAME),
+            'port create ' f'--network {self.NETWORK_NAME} {self.NAME}',
             parse_output=True,
         )
         id_ = json_output.get('id')
-        self.addCleanup(self.openstack, 'port delete %s' % id_)
+        self.addCleanup(self.openstack, f'port delete {id_}')
 
         raw_output = self.openstack(
             '--os-username admin '
-            'port set --mac-address 11:22:33:44:55:66 %s' % self.NAME
+            f'port set --mac-address 11:22:33:44:55:66 {self.NAME}'
         )
         self.assertOutput('', raw_output)
         json_output = self.openstack(
-            'port show %s' % self.NAME,
+            f'port show {self.NAME}',
             parse_output=True,
         )
         self.assertEqual(json_output.get('mac_address'), '11:22:33:44:55:66')
@@ -207,39 +203,39 @@ class PortTests(common.NetworkTagTests):
         """Test create, set, show, delete"""
         sg_name1 = uuid.uuid4().hex
         json_output = self.openstack(
-            'security group create %s' % sg_name1,
+            f'security group create {sg_name1}',
             parse_output=True,
         )
         sg_id1 = json_output.get('id')
-        self.addCleanup(self.openstack, 'security group delete %s' % sg_id1)
+        self.addCleanup(self.openstack, f'security group delete {sg_id1}')
 
         sg_name2 = uuid.uuid4().hex
         json_output = self.openstack(
-            'security group create %s' % sg_name2,
+            f'security group create {sg_name2}',
             parse_output=True,
         )
         sg_id2 = json_output.get('id')
-        self.addCleanup(self.openstack, 'security group delete %s' % sg_id2)
+        self.addCleanup(self.openstack, f'security group delete {sg_id2}')
 
         name = uuid.uuid4().hex
         json_output = self.openstack(
             'port create '
-            '--network %s '
-            '--security-group %s %s' % (self.NETWORK_NAME, sg_name1, name),
+            f'--network {self.NETWORK_NAME} '
+            f'--security-group {sg_name1} {name}',
             parse_output=True,
         )
         id1 = json_output.get('id')
-        self.addCleanup(self.openstack, 'port delete %s' % id1)
+        self.addCleanup(self.openstack, f'port delete {id1}')
         self.assertEqual(name, json_output.get('name'))
         self.assertEqual([sg_id1], json_output.get('security_group_ids'))
 
         raw_output = self.openstack(
-            'port set ' '--security-group %s %s' % (sg_name2, name)
+            'port set ' f'--security-group {sg_name2} {name}'
         )
         self.assertOutput('', raw_output)
 
         json_output = self.openstack(
-            'port show %s' % name,
+            f'port show {name}',
             parse_output=True,
         )
         self.assertEqual(name, json_output.get('name'))
@@ -256,15 +252,13 @@ class PortTests(common.NetworkTagTests):
         self.assertOutput('', raw_output)
 
         json_output = self.openstack(
-            'port show %s' % name,
+            f'port show {name}',
             parse_output=True,
         )
         self.assertEqual([sg_id2], json_output.get('security_group_ids'))
 
     def _create_resource_for_tag_test(self, name, args):
         return self.openstack(
-            '{} create --network {} {} {}'.format(
-                self.base_command, self.NETWORK_NAME, args, name
-            ),
+            f'{self.base_command} create --network {self.NETWORK_NAME} {args} {name}',
             parse_output=True,
         )
diff --git a/openstackclient/tests/functional/network/v2/test_router.py b/openstackclient/tests/functional/network/v2/test_router.py
index bd4261ac72..89d0652353 100644
--- a/openstackclient/tests/functional/network/v2/test_router.py
+++ b/openstackclient/tests/functional/network/v2/test_router.py
@@ -275,17 +275,16 @@ class RouterTests(common.NetworkTagTests):
         subnet_name = uuid.uuid4().hex
         router_name = uuid.uuid4().hex
 
-        self.openstack('network create %s' % network_name)
-        self.addCleanup(self.openstack, 'network delete %s' % network_name)
+        self.openstack(f'network create {network_name}')
+        self.addCleanup(self.openstack, f'network delete {network_name}')
 
         self.openstack(
-            'subnet create %s '
-            '--network %s --subnet-range 10.0.0.0/24'
-            % (subnet_name, network_name)
+            f'subnet create {subnet_name} '
+            f'--network {network_name} --subnet-range 10.0.0.0/24'
         )
 
-        self.openstack('router create %s' % router_name)
-        self.addCleanup(self.openstack, 'router delete %s' % router_name)
+        self.openstack(f'router create {router_name}')
+        self.addCleanup(self.openstack, f'router delete {router_name}')
 
         self.openstack(f'router add subnet {router_name} {subnet_name}')
         self.addCleanup(
@@ -295,24 +294,20 @@ class RouterTests(common.NetworkTagTests):
 
         out1 = (
             self.openstack(
-                'router add route %s '
-                '--route destination=10.0.10.0/24,gateway=10.0.0.10'
-                % router_name,
+                f'router add route {router_name} '
+                '--route destination=10.0.10.0/24,gateway=10.0.0.10',
                 parse_output=True,
             ),
         )
         self.assertEqual(1, len(out1[0]['routes']))
 
-        self.addCleanup(
-            self.openstack, 'router set %s --no-route' % router_name
-        )
+        self.addCleanup(self.openstack, f'router set {router_name} --no-route')
 
         out2 = (
             self.openstack(
-                'router add route %s '
+                f'router add route {router_name} '
                 '--route destination=10.0.10.0/24,gateway=10.0.0.10 '
-                '--route destination=10.0.11.0/24,gateway=10.0.0.11'
-                % router_name,
+                '--route destination=10.0.11.0/24,gateway=10.0.0.11',
                 parse_output=True,
             ),
         )
@@ -320,10 +315,9 @@ class RouterTests(common.NetworkTagTests):
 
         out3 = (
             self.openstack(
-                'router remove route %s '
+                f'router remove route {router_name} '
                 '--route destination=10.0.11.0/24,gateway=10.0.0.11 '
-                '--route destination=10.0.12.0/24,gateway=10.0.0.12'
-                % router_name,
+                '--route destination=10.0.12.0/24,gateway=10.0.0.12',
                 parse_output=True,
             ),
         )
diff --git a/openstackclient/tests/functional/object/v1/test_object.py b/openstackclient/tests/functional/object/v1/test_object.py
index 73044de9d1..68ca204337 100644
--- a/openstackclient/tests/functional/object/v1/test_object.py
+++ b/openstackclient/tests/functional/object/v1/test_object.py
@@ -59,7 +59,7 @@ class ObjectTests(common.ObjectStoreTests):
         items = self.parse_listing(raw_output)
         self.assert_show_fields(items, OBJECT_FIELDS)
 
-        raw_output = self.openstack('object list %s' % self.CONTAINER_NAME)
+        raw_output = self.openstack(f'object list {self.CONTAINER_NAME}')
         items = self.parse_listing(raw_output)
         self.assert_table_structure(items, BASIC_LIST_HEADERS)
 
@@ -69,15 +69,12 @@ class ObjectTests(common.ObjectStoreTests):
         tmp_file = 'tmp.txt'
         self.addCleanup(os.remove, tmp_file)
         self.openstack(
-            'object save %s %s --file %s'
-            % (self.CONTAINER_NAME, object_file, tmp_file)
+            f'object save {self.CONTAINER_NAME} {object_file} --file {tmp_file}'
         )
         # TODO(stevemar): Assert returned fields
 
         raw_output = self.openstack(
-            'object save {} {} --file -'.format(
-                self.CONTAINER_NAME, object_file
-            )
+            f'object save {self.CONTAINER_NAME} {object_file} --file -'
         )
         self.assertEqual(raw_output, 'test content')
 
@@ -91,6 +88,6 @@ class ObjectTests(common.ObjectStoreTests):
 
         self.openstack(f'object create {self.CONTAINER_NAME} {object_file}')
         raw_output = self.openstack(
-            'container delete -r %s' % self.CONTAINER_NAME
+            f'container delete -r {self.CONTAINER_NAME}'
         )
         self.assertEqual(0, len(raw_output))
diff --git a/openstackclient/tests/functional/volume/base.py b/openstackclient/tests/functional/volume/base.py
index ab05642eb1..d1d4ffe00e 100644
--- a/openstackclient/tests/functional/volume/base.py
+++ b/openstackclient/tests/functional/volume/base.py
@@ -40,21 +40,15 @@ class BaseVolumeTests(base.TestCase):
             current_status = output['status']
             if current_status == desired_status:
                 print(
-                    '{} {} now has status {}'.format(
-                        check_type, check_name, current_status
-                    )
+                    f'{check_type} {check_name} now has status {current_status}'
                 )
                 return
             print(
-                'Checking {} {} Waiting for {} current status: {}'.format(
-                    check_type, check_name, desired_status, current_status
-                )
+                f'Checking {check_type} {check_name} Waiting for {desired_status} current status: {current_status}'
             )
             if current_status in failures:
                 raise Exception(
-                    'Current status {} of {} {} is one of failures {}'.format(
-                        current_status, check_type, check_name, failures
-                    )
+                    f'Current status {current_status} of {check_type} {check_name} is one of failures {failures}'
                 )
             time.sleep(interval)
             total_sleep += interval
@@ -72,15 +66,9 @@ class BaseVolumeTests(base.TestCase):
             if check_name not in names:
                 print(f'{check_type} {check_name} is now deleted')
                 return
-            print(
-                'Checking {} {} Waiting for deleted'.format(
-                    check_type, check_name
-                )
-            )
+            print(f'Checking {check_type} {check_name} Waiting for deleted')
             time.sleep(interval)
             total_sleep += interval
         raise Exception(
-            'Timeout: {} {} was not deleted in {} seconds'.format(
-                check_type, check_name, wait
-            )
+            f'Timeout: {check_type} {check_name} was not deleted in {wait} seconds'
         )
diff --git a/openstackclient/tests/functional/volume/v1/test_volume_type.py b/openstackclient/tests/functional/volume/v1/test_volume_type.py
index 97c8b66c1c..b48dec642e 100644
--- a/openstackclient/tests/functional/volume/v1/test_volume_type.py
+++ b/openstackclient/tests/functional/volume/v1/test_volume_type.py
@@ -32,7 +32,7 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.assertEqual(name, cmd_output['name'])
 
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual(self.NAME, cmd_output['name'])
@@ -57,19 +57,19 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.assertEqual(name, cmd_output['name'])
 
         raw_output = self.openstack(
-            'volume type set --property a=b --property c=d %s' % name
+            f'volume type set --property a=b --property c=d {name}'
         )
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({'a': 'b', 'c': 'd'}, cmd_output['properties'])
 
-        raw_output = self.openstack('volume type unset --property a %s' % name)
+        raw_output = self.openstack(f'volume type unset --property a {name}')
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({'c': 'd'}, cmd_output['properties'])
@@ -84,21 +84,21 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.assertEqual(name, cmd_output['name'])
 
         raw_output = self.openstack(
-            'volume type set --property a=b --property c=d %s' % name
+            f'volume type set --property a=b --property c=d {name}'
         )
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({'a': 'b', 'c': 'd'}, cmd_output['properties'])
 
         raw_output = self.openstack(
-            'volume type unset --property a --property c %s' % name
+            f'volume type unset --property a --property c {name}'
         )
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({}, cmd_output['properties'])
@@ -106,9 +106,9 @@ class VolumeTypeTests(common.BaseVolumeTests):
     def test_multi_delete(self):
         vol_type1 = uuid.uuid4().hex
         vol_type2 = uuid.uuid4().hex
-        self.openstack('volume type create %s' % vol_type1)
+        self.openstack(f'volume type create {vol_type1}')
         time.sleep(5)
-        self.openstack('volume type create %s' % vol_type2)
+        self.openstack(f'volume type create {vol_type2}')
         time.sleep(5)
         cmd = f'volume type delete {vol_type1} {vol_type2}'
         raw_output = self.openstack(cmd)
diff --git a/openstackclient/tests/functional/volume/v2/test_volume_backup.py b/openstackclient/tests/functional/volume/v2/test_volume_backup.py
index 6bd37f4dc0..7ace71901c 100644
--- a/openstackclient/tests/functional/volume/v2/test_volume_backup.py
+++ b/openstackclient/tests/functional/volume/v2/test_volume_backup.py
@@ -56,4 +56,4 @@ class VolumeBackupTests(common.BaseVolumeTests):
         self.wait_for_status(
             "volume", backup_restored['volume_id'], "available"
         )
-        self.addCleanup(self.openstack, 'volume delete %s' % vol_id)
+        self.addCleanup(self.openstack, f'volume delete {vol_id}')
diff --git a/openstackclient/tests/functional/volume/v2/test_volume_type.py b/openstackclient/tests/functional/volume/v2/test_volume_type.py
index bdbced00f6..80bf85a5bb 100644
--- a/openstackclient/tests/functional/volume/v2/test_volume_type.py
+++ b/openstackclient/tests/functional/volume/v2/test_volume_type.py
@@ -32,7 +32,7 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.assertEqual(name, cmd_output['name'])
 
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual(name, cmd_output['name'])
@@ -57,19 +57,19 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.assertEqual(name, cmd_output['name'])
 
         raw_output = self.openstack(
-            'volume type set --property a=b --property c=d %s' % name
+            f'volume type set --property a=b --property c=d {name}'
         )
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({'a': 'b', 'c': 'd'}, cmd_output['properties'])
 
-        raw_output = self.openstack('volume type unset --property a %s' % name)
+        raw_output = self.openstack(f'volume type unset --property a {name}')
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({'c': 'd'}, cmd_output['properties'])
@@ -84,21 +84,21 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.assertEqual(name, cmd_output['name'])
 
         raw_output = self.openstack(
-            'volume type set --property a=b --property c=d %s' % name
+            f'volume type set --property a=b --property c=d {name}'
         )
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({'a': 'b', 'c': 'd'}, cmd_output['properties'])
 
         raw_output = self.openstack(
-            'volume type unset --property a --property c %s' % name
+            f'volume type unset --property a --property c {name}'
         )
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({}, cmd_output['properties'])
@@ -112,22 +112,20 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.addCleanup(self.openstack, 'volume type delete ' + name)
         self.assertEqual(name, cmd_output['name'])
 
-        raw_output = self.openstack(
-            'volume type set --project admin %s' % name
-        )
+        raw_output = self.openstack(f'volume type set --project admin {name}')
         self.assertEqual("", raw_output)
 
         raw_output = self.openstack(
-            'volume type unset --project admin %s' % name
+            f'volume type unset --project admin {name}'
         )
         self.assertEqual("", raw_output)
 
     def test_multi_delete(self):
         vol_type1 = uuid.uuid4().hex
         vol_type2 = uuid.uuid4().hex
-        self.openstack('volume type create %s' % vol_type1)
+        self.openstack(f'volume type create {vol_type1}')
         time.sleep(5)
-        self.openstack('volume type create %s' % vol_type2)
+        self.openstack(f'volume type create {vol_type2}')
         time.sleep(5)
         cmd = f'volume type delete {vol_type1} {vol_type2}'
         raw_output = self.openstack(cmd)
diff --git a/openstackclient/tests/functional/volume/v3/test_volume_type.py b/openstackclient/tests/functional/volume/v3/test_volume_type.py
index 78f9e4063f..421b3224f6 100644
--- a/openstackclient/tests/functional/volume/v3/test_volume_type.py
+++ b/openstackclient/tests/functional/volume/v3/test_volume_type.py
@@ -32,7 +32,7 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.assertEqual(name, cmd_output['name'])
 
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual(name, cmd_output['name'])
@@ -57,19 +57,19 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.assertEqual(name, cmd_output['name'])
 
         raw_output = self.openstack(
-            'volume type set --property a=b --property c=d %s' % name
+            f'volume type set --property a=b --property c=d {name}'
         )
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({'a': 'b', 'c': 'd'}, cmd_output['properties'])
 
-        raw_output = self.openstack('volume type unset --property a %s' % name)
+        raw_output = self.openstack(f'volume type unset --property a {name}')
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({'c': 'd'}, cmd_output['properties'])
@@ -84,21 +84,21 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.assertEqual(name, cmd_output['name'])
 
         raw_output = self.openstack(
-            'volume type set --property a=b --property c=d %s' % name
+            f'volume type set --property a=b --property c=d {name}'
         )
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({'a': 'b', 'c': 'd'}, cmd_output['properties'])
 
         raw_output = self.openstack(
-            'volume type unset --property a --property c %s' % name
+            f'volume type unset --property a --property c {name}'
         )
         self.assertEqual("", raw_output)
         cmd_output = self.openstack(
-            'volume type show %s' % name,
+            f'volume type show {name}',
             parse_output=True,
         )
         self.assertEqual({}, cmd_output['properties'])
@@ -112,22 +112,20 @@ class VolumeTypeTests(common.BaseVolumeTests):
         self.addCleanup(self.openstack, 'volume type delete ' + name)
         self.assertEqual(name, cmd_output['name'])
 
-        raw_output = self.openstack(
-            'volume type set --project admin %s' % name
-        )
+        raw_output = self.openstack(f'volume type set --project admin {name}')
         self.assertEqual("", raw_output)
 
         raw_output = self.openstack(
-            'volume type unset --project admin %s' % name
+            f'volume type unset --project admin {name}'
         )
         self.assertEqual("", raw_output)
 
     def test_multi_delete(self):
         vol_type1 = uuid.uuid4().hex
         vol_type2 = uuid.uuid4().hex
-        self.openstack('volume type create %s' % vol_type1)
+        self.openstack(f'volume type create {vol_type1}')
         time.sleep(5)
-        self.openstack('volume type create %s' % vol_type2)
+        self.openstack(f'volume type create {vol_type2}')
         time.sleep(5)
         cmd = f'volume type delete {vol_type1} {vol_type2}'
         raw_output = self.openstack(cmd)
diff --git a/openstackclient/tests/unit/api/test_object_store_v1.py b/openstackclient/tests/unit/api/test_object_store_v1.py
index 39bc26a61d..3ff22f5090 100644
--- a/openstackclient/tests/unit/api/test_object_store_v1.py
+++ b/openstackclient/tests/unit/api/test_object_store_v1.py
@@ -135,16 +135,18 @@ class TestContainer(TestObjectAPIv1):
         self.requests_mock.register_uri(
             'GET',
             FAKE_URL
-            + '?marker=%s&limit=1&format=json'
-            % LIST_CONTAINER_RESP[0]['name'],
+            + '?marker={}&limit=1&format=json'.format(
+                LIST_CONTAINER_RESP[0]['name']
+            ),
             json=[LIST_CONTAINER_RESP[1]],
             status_code=200,
         )
         self.requests_mock.register_uri(
             'GET',
             FAKE_URL
-            + '?marker=%s&limit=1&format=json'
-            % LIST_CONTAINER_RESP[1]['name'],
+            + '?marker={}&limit=1&format=json'.format(
+                LIST_CONTAINER_RESP[1]['name']
+            ),
             json=[],
             status_code=200,
         )
diff --git a/openstackclient/tests/unit/identity/v3/test_group.py b/openstackclient/tests/unit/identity/v3/test_group.py
index 04e5a9cf9a..bd983c6180 100644
--- a/openstackclient/tests/unit/identity/v3/test_group.py
+++ b/openstackclient/tests/unit/identity/v3/test_group.py
@@ -109,12 +109,9 @@ class TestGroupAddUser(TestGroup):
             self.cmd.take_action(parsed_args)
             self.fail('CommandError should be raised.')
         except exceptions.CommandError as e:
-            msg = "1 of 2 users not added to group %s." % self._group.name
+            msg = f"1 of 2 users not added to group {self._group.name}."
             self.assertEqual(msg, str(e))
-        msg = ("%(user)s not added to group %(group)s: ") % {
-            'user': self.users[0].name,
-            'group': self._group.name,
-        }
+        msg = f"{self.users[0].name} not added to group {self._group.name}: "
         mock_error.assert_called_once_with(msg)
 
 
@@ -561,12 +558,9 @@ class TestGroupRemoveUser(TestGroup):
             self.cmd.take_action(parsed_args)
             self.fail('CommandError should be raised.')
         except exceptions.CommandError as e:
-            msg = "1 of 2 users not removed from group %s." % self._group.id
+            msg = f"1 of 2 users not removed from group {self._group.id}."
             self.assertEqual(msg, str(e))
-        msg = ("%(user)s not removed from group %(group)s: ") % {
-            'user': self.users[0].id,
-            'group': self._group.id,
-        }
+        msg = f"{self.users[0].id} not removed from group {self._group.id}: "
         mock_error.assert_called_once_with(msg)
 
 
diff --git a/openstackclient/tests/unit/image/v2/test_metadef_objects.py b/openstackclient/tests/unit/image/v2/test_metadef_objects.py
index 323d8ea151..4996060d9d 100644
--- a/openstackclient/tests/unit/image/v2/test_metadef_objects.py
+++ b/openstackclient/tests/unit/image/v2/test_metadef_objects.py
@@ -256,7 +256,6 @@ class TestMetadefObjectPropertyShow(fakes.TestImagev2):
             parsed_args,
         )
         self.assertIn(
-            'Property %s not found in object %s.'
-            % (parsed_args.property, parsed_args.object),
+            f'Property {parsed_args.property} not found in object {parsed_args.object}.',
             str(exc),
         )
diff --git a/openstackclient/tests/unit/integ/base.py b/openstackclient/tests/unit/integ/base.py
index cecf122b2a..e61945a771 100644
--- a/openstackclient/tests/unit/integ/base.py
+++ b/openstackclient/tests/unit/integ/base.py
@@ -18,7 +18,7 @@ from openstackclient.tests.unit import utils
 
 
 HOST = "192.168.5.41"
-URL_BASE = "http://%s/identity" % HOST
+URL_BASE = f"http://{HOST}/identity"
 
 V2_AUTH_URL = URL_BASE + "/v2.0/"
 V2_VERSION_RESP = {
diff --git a/openstackclient/tests/unit/network/v2/test_network_qos_rule.py b/openstackclient/tests/unit/network/v2/test_network_qos_rule.py
index 132902fb31..39e6368735 100644
--- a/openstackclient/tests/unit/network/v2/test_network_qos_rule.py
+++ b/openstackclient/tests/unit/network/v2/test_network_qos_rule.py
@@ -903,9 +903,9 @@ class TestSetNetworkQosRuleMinimumBandwidth(TestNetworkQosRule):
             self.cmd.take_action(parsed_args)
         except exceptions.CommandError as e:
             msg = (
-                'Failed to set Network QoS rule ID "%(rule)s": Rule type '
+                f'Failed to set Network QoS rule ID "{self.new_rule.id}": Rule type '
                 '"minimum-bandwidth" only requires arguments: direction, '
-                'min_kbps' % {'rule': self.new_rule.id}
+                'min_kbps'
             )
             self.assertEqual(msg, str(e))
 
@@ -1007,9 +1007,9 @@ class TestSetNetworkQosRuleMinimumPacketRate(TestNetworkQosRule):
             self.cmd.take_action(parsed_args)
         except exceptions.CommandError as e:
             msg = (
-                'Failed to set Network QoS rule ID "%(rule)s": Rule type '
+                f'Failed to set Network QoS rule ID "{self.new_rule.id}": Rule type '
                 '"minimum-packet-rate" only requires arguments: direction, '
-                'min_kpps' % {'rule': self.new_rule.id}
+                'min_kpps'
             )
             self.assertEqual(msg, str(e))
 
@@ -1111,9 +1111,8 @@ class TestSetNetworkQosRuleDSCPMarking(TestNetworkQosRule):
             self.cmd.take_action(parsed_args)
         except exceptions.CommandError as e:
             msg = (
-                'Failed to set Network QoS rule ID "%(rule)s": Rule type '
+                f'Failed to set Network QoS rule ID "{self.new_rule.id}": Rule type '
                 '"dscp-marking" only requires arguments: dscp_mark'
-                % {'rule': self.new_rule.id}
             )
             self.assertEqual(msg, str(e))
 
@@ -1249,7 +1248,7 @@ class TestSetNetworkQosRuleBandwidthLimit(TestNetworkQosRule):
         self.addCleanup(self._reset_direction, self.new_rule.direction)
 
         arglist = [
-            '--%s' % direction,
+            f'--{direction}',
             self.new_rule.qos_policy_id,
             self.new_rule.id,
         ]
@@ -1288,9 +1287,9 @@ class TestSetNetworkQosRuleBandwidthLimit(TestNetworkQosRule):
             self.cmd.take_action(parsed_args)
         except exceptions.CommandError as e:
             msg = (
-                'Failed to set Network QoS rule ID "%(rule)s": Rule type '
+                f'Failed to set Network QoS rule ID "{self.new_rule.id}": Rule type '
                 '"bandwidth-limit" only requires arguments: direction, '
-                'max_burst_kbps, max_kbps' % {'rule': self.new_rule.id}
+                'max_burst_kbps, max_kbps'
             )
             self.assertEqual(msg, str(e))
 
diff --git a/openstackclient/tests/unit/network/v2/test_network_trunk.py b/openstackclient/tests/unit/network/v2/test_network_trunk.py
index 153d7f9959..064c44f371 100644
--- a/openstackclient/tests/unit/network/v2/test_network_trunk.py
+++ b/openstackclient/tests/unit/network/v2/test_network_trunk.py
@@ -143,13 +143,12 @@ class TestCreateNetworkTrunk(TestNetworkTrunk):
             "--parent-port",
             self.new_trunk.port_id,
             "--subport",
-            'port=%(port)s,segmentation-type=%(seg_type)s,'
-            'segmentation-id=%(seg_id)s'
-            % {
-                'seg_id': subport['segmentation_id'],
-                'seg_type': subport['segmentation_type'],
-                'port': subport['port_id'],
-            },
+            'port={port},segmentation-type={seg_type},'
+            'segmentation-id={seg_id}'.format(
+                seg_id=subport['segmentation_id'],
+                seg_type=subport['segmentation_type'],
+                port=subport['port_id'],
+            ),
             self.new_trunk.name,
         ]
         verifylist = [
@@ -194,12 +193,11 @@ class TestCreateNetworkTrunk(TestNetworkTrunk):
             "--parent-port",
             self.new_trunk.port_id,
             "--subport",
-            "port=%(port)s,segmentation-type=%(seg_type)s,"
-            "segmentation-id=boom"
-            % {
-                'seg_type': subport['segmentation_type'],
-                'port': subport['port_id'],
-            },
+            "port={port},segmentation-type={seg_type},"
+            "segmentation-id=boom".format(
+                seg_type=subport['segmentation_type'],
+                port=subport['port_id'],
+            ),
             self.new_trunk.name,
         ]
         verifylist = [
@@ -265,12 +263,10 @@ class TestCreateNetworkTrunk(TestNetworkTrunk):
             '--parent-port',
             self.new_trunk.port_id,
             '--subport',
-            'segmentation-type=%(seg_type)s,'
-            'segmentation-id=%(seg_id)s'
-            % {
-                'seg_id': subport['segmentation_id'],
-                'seg_type': subport['segmentation_type'],
-            },
+            'segmentation-type={seg_type},' 'segmentation-id={seg_id}'.format(
+                seg_id=subport['segmentation_id'],
+                seg_type=subport['segmentation_type'],
+            ),
             self.new_trunk.name,
         ]
         verifylist = [
@@ -585,7 +581,7 @@ class TestSetNetworkTrunk(TestNetworkTrunk):
 
     def _test_set_network_trunk_attr(self, attr, value):
         arglist = [
-            '--%s' % attr,
+            f'--{attr}',
             value,
             self._trunk[attr],
         ]
@@ -674,13 +670,12 @@ class TestSetNetworkTrunk(TestNetworkTrunk):
         subport = self._trunk['sub_ports'][0]
         arglist = [
             '--subport',
-            'port=%(port)s,segmentation-type=%(seg_type)s,'
-            'segmentation-id=%(seg_id)s'
-            % {
-                'seg_id': subport['segmentation_id'],
-                'seg_type': subport['segmentation_type'],
-                'port': subport['port_id'],
-            },
+            'port={port},segmentation-type={seg_type},'
+            'segmentation-id={seg_id}'.format(
+                seg_id=subport['segmentation_id'],
+                seg_type=subport['segmentation_type'],
+                port=subport['port_id'],
+            ),
             self._trunk['name'],
         ]
         verifylist = [
@@ -732,12 +727,10 @@ class TestSetNetworkTrunk(TestNetworkTrunk):
         subport = self._trunk['sub_ports'][0]
         arglist = [
             '--subport',
-            'segmentation-type=%(seg_type)s,'
-            'segmentation-id=%(seg_id)s'
-            % {
-                'seg_id': subport['segmentation_id'],
-                'seg_type': subport['segmentation_type'],
-            },
+            'segmentation-type={seg_type},' 'segmentation-id={seg_id}'.format(
+                seg_id=subport['segmentation_id'],
+                seg_type=subport['segmentation_type'],
+            ),
             self._trunk['name'],
         ]
         verifylist = [
@@ -776,7 +769,8 @@ class TestSetNetworkTrunk(TestNetworkTrunk):
         with testtools.ExpectedException(exceptions.CommandError) as e:
             self.cmd.take_action(parsed_args)
             self.assertEqual(
-                "Failed to set trunk '%s': " % self._trunk['name'], str(e)
+                "Failed to set trunk '{}': ".format(self._trunk['name']),
+                str(e),
             )
         attrs = {'name': 'reallylongname'}
         self.network_client.update_trunk.assert_called_once_with(
@@ -805,7 +799,9 @@ class TestSetNetworkTrunk(TestNetworkTrunk):
         with testtools.ExpectedException(exceptions.CommandError) as e:
             self.cmd.take_action(parsed_args)
             self.assertEqual(
-                "Failed to add subports to trunk '%s': " % self._trunk['name'],
+                "Failed to add subports to trunk '{}': ".format(
+                    self._trunk['name']
+                ),
                 str(e),
             )
         self.network_client.update_trunk.assert_called_once_with(self._trunk)
diff --git a/openstackclient/tests/unit/network/v2/test_port.py b/openstackclient/tests/unit/network/v2/test_port.py
index 7d19636510..d7592e99be 100644
--- a/openstackclient/tests/unit/network/v2/test_port.py
+++ b/openstackclient/tests/unit/network/v2/test_port.py
@@ -179,7 +179,7 @@ class TestCreatePort(TestPort):
             '--mac-address',
             'aa:aa:aa:aa:aa:aa',
             '--fixed-ip',
-            'subnet=%s,ip-address=10.0.0.2' % self.fake_subnet.id,
+            f'subnet={self.fake_subnet.id},ip-address=10.0.0.2',
             '--description',
             self._port.description,
             '--device',
@@ -866,7 +866,7 @@ class TestCreatePort(TestPort):
             'test-port',
         ]
         if policy:
-            arglist += ['--numa-policy-%s' % policy]
+            arglist += [f'--numa-policy-{policy}']
 
         numa_affinity_policy = None if not policy else policy
         verifylist = [
@@ -877,7 +877,7 @@ class TestCreatePort(TestPort):
             ('name', 'test-port'),
         ]
         if policy:
-            verifylist.append(('numa_policy_%s' % policy, True))
+            verifylist.append((f'numa_policy_{policy}', True))
 
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
@@ -1418,7 +1418,7 @@ class TestListPort(compute_fakes.FakeClientMixin, TestPort):
         ip_address = self._ports[0].fixed_ips[0]['ip_address']
         arglist = [
             '--fixed-ip',
-            "ip-address=%s" % ip_address,
+            f"ip-address={ip_address}",
         ]
         verifylist = [('fixed_ip', [{'ip-address': ip_address}])]
 
@@ -1428,7 +1428,7 @@ class TestListPort(compute_fakes.FakeClientMixin, TestPort):
 
         self.network_client.ports.assert_called_once_with(
             **{
-                'fixed_ips': ['ip_address=%s' % ip_address],
+                'fixed_ips': [f'ip_address={ip_address}'],
                 'fields': LIST_FIELDS_TO_RETRIEVE,
             }
         )
@@ -1439,7 +1439,7 @@ class TestListPort(compute_fakes.FakeClientMixin, TestPort):
         ip_address_ss = self._ports[0].fixed_ips[0]['ip_address'][:-1]
         arglist = [
             '--fixed-ip',
-            "ip-substring=%s" % ip_address_ss,
+            f"ip-substring={ip_address_ss}",
         ]
         verifylist = [('fixed_ip', [{'ip-substring': ip_address_ss}])]
 
@@ -1449,7 +1449,7 @@ class TestListPort(compute_fakes.FakeClientMixin, TestPort):
 
         self.network_client.ports.assert_called_once_with(
             **{
-                'fixed_ips': ['ip_address_substr=%s' % ip_address_ss],
+                'fixed_ips': [f'ip_address_substr={ip_address_ss}'],
                 'fields': LIST_FIELDS_TO_RETRIEVE,
             }
         )
@@ -1460,7 +1460,7 @@ class TestListPort(compute_fakes.FakeClientMixin, TestPort):
         subnet_id = self._ports[0].fixed_ips[0]['subnet_id']
         arglist = [
             '--fixed-ip',
-            "subnet=%s" % subnet_id,
+            f"subnet={subnet_id}",
         ]
         verifylist = [('fixed_ip', [{'subnet': subnet_id}])]
 
@@ -1475,7 +1475,7 @@ class TestListPort(compute_fakes.FakeClientMixin, TestPort):
 
         self.network_client.ports.assert_called_once_with(
             **{
-                'fixed_ips': ['subnet_id=%s' % subnet_id],
+                'fixed_ips': [f'subnet_id={subnet_id}'],
                 'fields': LIST_FIELDS_TO_RETRIEVE,
             }
         )
@@ -1505,8 +1505,8 @@ class TestListPort(compute_fakes.FakeClientMixin, TestPort):
         self.network_client.ports.assert_called_once_with(
             **{
                 'fixed_ips': [
-                    'subnet_id=%s' % subnet_id,
-                    'ip_address=%s' % ip_address,
+                    f'subnet_id={subnet_id}',
+                    f'ip_address={ip_address}',
                 ],
                 'fields': LIST_FIELDS_TO_RETRIEVE,
             }
@@ -1519,9 +1519,9 @@ class TestListPort(compute_fakes.FakeClientMixin, TestPort):
         ip_address = self._ports[0].fixed_ips[0]['ip_address']
         arglist = [
             '--fixed-ip',
-            "subnet=%s" % subnet_id,
+            f"subnet={subnet_id}",
             '--fixed-ip',
-            "ip-address=%s" % ip_address,
+            f"ip-address={ip_address}",
         ]
         verifylist = [
             ('fixed_ip', [{'subnet': subnet_id}, {'ip-address': ip_address}])
@@ -1542,8 +1542,8 @@ class TestListPort(compute_fakes.FakeClientMixin, TestPort):
         self.network_client.ports.assert_called_once_with(
             **{
                 'fixed_ips': [
-                    'subnet_id=%s' % subnet_id,
-                    'ip_address=%s' % ip_address,
+                    f'subnet_id={subnet_id}',
+                    f'ip_address={ip_address}',
                 ],
                 'fields': LIST_FIELDS_TO_RETRIEVE,
             }
@@ -2360,11 +2360,11 @@ class TestSetPort(TestPort):
 
     def _test_create_with_numa_affinity_policy(self, policy):
         arglist = [
-            '--numa-policy-%s' % policy,
+            f'--numa-policy-{policy}',
             self._port.id,
         ]
         verifylist = [
-            ('numa_policy_%s' % policy, True),
+            (f'numa_policy_{policy}', True),
             (
                 'port',
                 self._port.id,
diff --git a/openstackclient/tests/unit/utils.py b/openstackclient/tests/unit/utils.py
index b9f38f950e..2a39ca4831 100644
--- a/openstackclient/tests/unit/utils.py
+++ b/openstackclient/tests/unit/utils.py
@@ -62,7 +62,7 @@ class TestCase(testtools.TestCase):
 
         if m.called:
             if not msg:
-                msg = 'method %s should not have been called' % m
+                msg = f'method {m} should not have been called'
             self.fail(msg)
 
 
@@ -90,7 +90,7 @@ class TestCommand(TestCase):
                 argparse.ArgumentError,
             ):
                 raise ParserException(
-                    "Argument parse failed: %s" % stderr.getvalue()
+                    f"Argument parse failed: {stderr.getvalue()}"
                 )
         for av in verify_args:
             attr, value = av
diff --git a/pyproject.toml b/pyproject.toml
index 6b13ff2461..9a30d5bc50 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,7 @@ quote-style = "preserve"
 docstring-code-format = true
 
 [tool.ruff.lint]
-select = ["E4", "E7", "E9", "F", "S"]
+select = ["E4", "E7", "E9", "F", "S", "U"]
 
 [tool.ruff.lint.per-file-ignores]
 "openstackclient/tests/*" = ["S"]