diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 4760fdcc3..0efe3cb54 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -15,26 +15,29 @@ repos:
       - id: check-json
       - id: check-merge-conflict
       - id: debug-statements
+      - id: check-yaml
+        files: .*\.(yaml|yml)$
   - repo: https://github.com/PyCQA/bandit
     rev: 1.8.3
     hooks:
       - id: bandit
         # B104: Possible binding to all interfaces
+        # B110: Try, Except, Pass detected
         # B303: Blacklist use of insecure MD2, MD4, MD5, or SHA1 hash functions
         # B311: Standard pseudo-random generators are not suitable for security/cryptographic purpose
-        args: ['-n5', '-sB104,B303,B311']
+        args: ['-n5', '-sB104,B110,B303,B311']
         files: 'neutron_lib/'
         exclude: 'neutron_lib/tests'
-  - repo: https://github.com/Lucas-C/pre-commit-hooks
+  - repo: https://github.com/lucas-c/pre-commit-hooks
     rev: v1.5.5
     hooks:
       - id: remove-tabs
         exclude: '.*\.(svg)$'
-  - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v1.15.0
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.12.1
     hooks:
-      - id: mypy
-        pass_filenames: false
+      - id: ruff-check
+        args: ['--fix', '--unsafe-fixes']
   - repo: https://opendev.org/openstack/hacking
     rev: 7.0.0
     hooks:
@@ -43,6 +46,16 @@ repos:
           - flake8-import-order~=0.18.2
           - neutron
         exclude: '^(doc|releasenotes|tools)/.*$'
+  - repo: https://github.com/hhatto/autopep8
+    rev: v2.3.2
+    hooks:
+      - id: autopep8
+        files: '^.*\.py$'
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v1.16.1
+    hooks:
+      - id: mypy
+        pass_filenames: false
   - repo: local
     hooks:
       - id: check-unit-test-structure
diff --git a/api-ref/source/v2/parameters.yaml b/api-ref/source/v2/parameters.yaml
index b9c1631b9..e2e82f792 100644
--- a/api-ref/source/v2/parameters.yaml
+++ b/api-ref/source/v2/parameters.yaml
@@ -1971,7 +1971,6 @@ agent:
   in: body
   required: true
   type: object
-  type: string
 agent_resources_synced:
   description: |
     The value ``null`` means no resource view synchronization to Placement
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 86d7707c8..e9cf8b065 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -52,7 +52,7 @@ templates_path = []
 source_suffix = '.rst'
 
 # The encoding of source files.
-#source_encoding = 'utf-8'
+# source_encoding = 'utf-8'
 
 # The master doctree document.
 master_doc = 'index'
@@ -63,13 +63,13 @@ copyright = '2015-present, OpenStack Foundation.'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
-#language = None
+# language = None
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
-#today = ''
+# today = ''
 # Else, today_fmt is used as the format for a strftime call.
-#today_fmt = '%B %d, %Y'
+# today_fmt = '%B %d, %Y'
 
 # List of documents that shouldn't be included in the build.
 # unused_docs = []
@@ -79,14 +79,14 @@ copyright = '2015-present, OpenStack Foundation.'
 exclude_trees = []
 
 # The reST default role (for this markup: `text`) to use for all documents.
-#default_role = None
+# default_role = None
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
-#add_function_parentheses = True
+# add_function_parentheses = True
 
 # If true, the current module name will be prepended to all description
 # unit titles (such as .. function::).
-#add_module_names = True
+# add_module_names = True
 
 # If true, sectionauthor and moduleauthor directives will be shown in the
 # output. They are ignored by default.
@@ -120,26 +120,26 @@ html_theme = 'openstackdocs'
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
-#html_theme_options = {}
+# html_theme_options = {}
 
 # Add any paths that contain custom themes here, relative to this directory.
-#html_theme_path = ['_theme']
+# html_theme_path = ['_theme']
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
-#html_title = None
+# html_title = None
 
 # A shorter title for the navigation bar.  Default is the same as html_title.
-#html_short_title = None
+# html_short_title = None
 
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
-#html_logo = None
+# html_logo = None
 
 # The name of an image file (within the static path) to use as favicon of the
 # docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
 # pixels large.
-#html_favicon = None
+# html_favicon = None
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
@@ -148,46 +148,46 @@ html_theme = 'openstackdocs'
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
-#html_use_smartypants = True
+# html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
-#html_sidebars = {}
+# html_sidebars = {}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
-#html_additional_pages = {}
+# html_additional_pages = {}
 
 # If false, no module index is generated.
-#html_use_modindex = True
+# html_use_modindex = True
 
 # If false, no index is generated.
-#html_use_index = True
+# html_use_index = True
 
 # If true, the index is split into individual pages for each letter.
-#html_split_index = False
+# html_split_index = False
 
 # If true, links to the reST sources are added to the pages.
-#html_show_sourcelink = True
+# html_show_sourcelink = True
 
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
-#html_use_opensearch = ''
+# html_use_opensearch = ''
 
 # If nonempty, this is the file name suffix for HTML files (e.g. ".xhtml").
-#html_file_suffix = ''
+# html_file_suffix = ''
 
 # Output file base name for HTML help builder.
-#htmlhelp_basename = 'neutronlibdoc'
+# htmlhelp_basename = 'neutronlibdoc'
 
 
 # -- Options for LaTeX output ------------------------------------------------
 
 # The paper size ('letter' or 'a4').
-#latex_paper_size = 'letter'
+# latex_paper_size = 'letter'
 
 # The font size ('10pt', '11pt' or '12pt').
-#latex_font_size = '10pt'
+# latex_font_size = '10pt'
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author,
@@ -199,20 +199,20 @@ latex_documents = [
 
 # The name of an image file (relative to this directory) to place at the top of
 # the title page.
-#latex_logo = None
+# latex_logo = None
 
 # For "manual" documents, if this is true, then toplevel headings are parts,
 # not chapters.
-#latex_use_parts = False
+# latex_use_parts = False
 
 # Additional stuff for the LaTeX preamble.
-#latex_preamble = ''
+# latex_preamble = ''
 
 # Documents to append as an appendix to all manuals.
-#latex_appendices = []
+# latex_appendices = []
 
 # If false, no module index is generated.
-#latex_use_modindex = True
+# latex_use_modindex = True
 
 latex_elements = {
     'makeindex': '',
diff --git a/neutron_lib/agent/topics.py b/neutron_lib/agent/topics.py
index 83e843456..bea7b9bab 100644
--- a/neutron_lib/agent/topics.py
+++ b/neutron_lib/agent/topics.py
@@ -65,5 +65,5 @@ def get_topic_name(prefix, table, operation, host=None):
     :returns: The topic name.
     """
     if host:
-        return '{}-{}-{}.{}'.format(prefix, table, operation, host)
-    return '{}-{}-{}'.format(prefix, table, operation)
+        return f'{prefix}-{table}-{operation}.{host}'
+    return f'{prefix}-{table}-{operation}'
diff --git a/neutron_lib/api/converters.py b/neutron_lib/api/converters.py
index ec809d80a..6633b67be 100644
--- a/neutron_lib/api/converters.py
+++ b/neutron_lib/api/converters.py
@@ -218,7 +218,7 @@ def convert_ip_to_canonical_format(value):
         ip = netaddr.IPAddress(value)
         if ip.version == constants.IP_VERSION_6:
             return str(ip.format(dialect=netaddr.ipv6_compact))
-    except Exception:  # nosec B110
+    except Exception:  # noqa: S110
         # netaddr may raise all kinds of exceptions (ValueError,
         # AttributeError...) if the input is not a valid IP address. Instead of
         # catching them one by one, just catch all exceptions at once.
diff --git a/neutron_lib/api/definitions/address_scope.py b/neutron_lib/api/definitions/address_scope.py
index c9a104bc9..2973e39d1 100644
--- a/neutron_lib/api/definitions/address_scope.py
+++ b/neutron_lib/api/definitions/address_scope.py
@@ -19,8 +19,8 @@ from neutron_lib.db import constants as db_constants
 
 ADDRESS_SCOPE = 'address_scope'
 ADDRESS_SCOPE_ID = 'address_scope_id'
-IPV4_ADDRESS_SCOPE = 'ipv4_%s' % ADDRESS_SCOPE
-IPV6_ADDRESS_SCOPE = 'ipv6_%s' % ADDRESS_SCOPE
+IPV4_ADDRESS_SCOPE = f'ipv4_{ADDRESS_SCOPE}'
+IPV6_ADDRESS_SCOPE = f'ipv6_{ADDRESS_SCOPE}'
 
 ALIAS = 'address-scope'
 IS_SHIM_EXTENSION = False
diff --git a/neutron_lib/api/definitions/bgp.py b/neutron_lib/api/definitions/bgp.py
index 8307ca06b..c99eecab0 100644
--- a/neutron_lib/api/definitions/bgp.py
+++ b/neutron_lib/api/definitions/bgp.py
@@ -28,7 +28,7 @@ DESCRIPTION = ("Discover and advertise routes for Neutron prefixes "
 UPDATED_TIMESTAMP = '2016-05-10T15:37:00-00:00'
 BGP_SPEAKER_RESOURCE_NAME = 'bgp-speaker'
 BGP_SPEAKER_BODY_KEY_NAME = 'bgp_speaker'
-BGP_SPEAKERS = '%ss' % BGP_SPEAKER_BODY_KEY_NAME
+BGP_SPEAKERS = f'{BGP_SPEAKER_BODY_KEY_NAME}s'
 BGP_PEER_BODY_KEY_NAME = 'bgp_peer'
 
 
diff --git a/neutron_lib/api/definitions/bgpvpn.py b/neutron_lib/api/definitions/bgpvpn.py
index fecd9234a..7908ee0a5 100644
--- a/neutron_lib/api/definitions/bgpvpn.py
+++ b/neutron_lib/api/definitions/bgpvpn.py
@@ -27,14 +27,13 @@ UINT16_REGEX = (r'(0|[1-9]\d{0,3}|[1-5]\d{4}|6[0-4]\d{3}|65[0-4]\d{2}'
 # Regular expression to validate 8 bits unsigned int
 UINT8_REGEX = (r'(0|[1-9]\d{0,1}|1\d{2}|2[0-4]\d|25[0-5])')
 # Regular expression to validate IPv4 address
-IP4_REGEX = (r'(%s\.%s\.%s\.%s)') % (UINT8_REGEX, UINT8_REGEX, UINT8_REGEX,
-                                     UINT8_REGEX)
+IP4_REGEX = (rf'({UINT8_REGEX}\.{UINT8_REGEX}\.{UINT8_REGEX}\.{UINT8_REGEX})')
 # Regular expression to validate Route Target list format
 # Support of the Type 0, Type 1 and Type 2, cf. chapter 4.2 in RFC 4364
 # Also validates Route Distinguisher list format
-RTRD_REGEX = (r'^(%s:%s|%s:%s|%s:%s)$') % (UINT16_REGEX, UINT32_REGEX,
-                                           IP4_REGEX, UINT16_REGEX,
-                                           UINT32_REGEX, UINT16_REGEX)
+RTRD_REGEX = (
+    rf'^({UINT16_REGEX}:{UINT32_REGEX}|{IP4_REGEX}:'
+    rf'{UINT16_REGEX}|{UINT32_REGEX}:{UINT16_REGEX})$')
 
 # The alias of the extension.
 ALIAS = 'bgpvpn'
diff --git a/neutron_lib/api/definitions/l3_ext_gw_mode.py b/neutron_lib/api/definitions/l3_ext_gw_mode.py
index 7dbc11be1..b7bf64e27 100644
--- a/neutron_lib/api/definitions/l3_ext_gw_mode.py
+++ b/neutron_lib/api/definitions/l3_ext_gw_mode.py
@@ -31,7 +31,7 @@ UPDATED_TIMESTAMP = '2013-03-28T10:00:00-00:00'
 RESOURCE_NAME = l3.ROUTER
 COLLECTION_NAME = l3.ROUTERS
 
-routers: typing.Dict[str, typing.Any] = copy.deepcopy(
+routers: dict[str, typing.Any] = copy.deepcopy(
     l3.RESOURCE_ATTRIBUTE_MAP[COLLECTION_NAME]
 )
 routers[l3.EXTERNAL_GW_INFO]['validate']['type:dict_or_nodata'][
diff --git a/neutron_lib/api/definitions/l3_ext_gw_multihoming.py b/neutron_lib/api/definitions/l3_ext_gw_multihoming.py
index dbede7e51..7f5855c9a 100644
--- a/neutron_lib/api/definitions/l3_ext_gw_multihoming.py
+++ b/neutron_lib/api/definitions/l3_ext_gw_multihoming.py
@@ -30,7 +30,7 @@ UPDATED_TIMESTAMP = '2023-01-18T00:00:00-00:00'
 RESOURCE_NAME = l3.ROUTER
 COLLECTION_NAME = l3.ROUTERS
 
-external_gw_info_validate: typing.Dict[str, typing.Any] = copy.deepcopy(
+external_gw_info_validate: dict[str, typing.Any] = copy.deepcopy(
     l3_ext_gw_mode.RESOURCE_ATTRIBUTE_MAP[COLLECTION_NAME][l3.EXTERNAL_GW_INFO]
     ['validate']['type:dict_or_nodata']
 )
diff --git a/neutron_lib/api/definitions/qos_gateway_ip.py b/neutron_lib/api/definitions/qos_gateway_ip.py
index 70943ccc1..e50199390 100644
--- a/neutron_lib/api/definitions/qos_gateway_ip.py
+++ b/neutron_lib/api/definitions/qos_gateway_ip.py
@@ -30,7 +30,7 @@ UPDATED_TIMESTAMP = '2018-02-24T00:00:00-00:00'
 RESOURCE_NAME = l3.ROUTER
 COLLECTION_NAME = l3.ROUTERS
 
-routers: typing.Dict[str, typing.Any] = copy.deepcopy(
+routers: dict[str, typing.Any] = copy.deepcopy(
     l3_ext_gw_mode.RESOURCE_ATTRIBUTE_MAP[COLLECTION_NAME]
 )
 routers[l3.EXTERNAL_GW_INFO]['validate']['type:dict_or_nodata'][
diff --git a/neutron_lib/api/extensions.py b/neutron_lib/api/extensions.py
index cf90f7d2d..77172dee6 100644
--- a/neutron_lib/api/extensions.py
+++ b/neutron_lib/api/extensions.py
@@ -14,7 +14,6 @@
 #    under the License.
 
 import abc
-import typing
 
 from neutron_lib._i18n import _
 from neutron_lib import constants
@@ -184,7 +183,7 @@ class APIExtensionDescriptor(ExtensionDescriptor):
     If extension implementations need to override the default behavior of
     this class they can override the respective method directly.
     """
-    api_definition: typing.Union[constants.Sentinel, object] = _UNSET
+    api_definition: constants.Sentinel | object = _UNSET
 
     @classmethod
     def _assert_api_definition(cls, attr=None):
diff --git a/neutron_lib/api/validators/__init__.py b/neutron_lib/api/validators/__init__.py
index 1ca6e7414..9edb932c0 100644
--- a/neutron_lib/api/validators/__init__.py
+++ b/neutron_lib/api/validators/__init__.py
@@ -37,8 +37,8 @@ UNLIMITED = None
 
 # Note: In order to ensure that the MAC address is unicast the first byte
 # must be even.
-MAC_PATTERN = "^{}[aceACE02468](:{}{{2}}){{5}}$".format(constants.HEX_ELEM,
-                                                        constants.HEX_ELEM)
+_HEX_ELEM = constants.HEX_ELEM
+MAC_PATTERN = f"^{_HEX_ELEM}[aceACE02468](:{_HEX_ELEM}{{2}}){{5}}$"
 
 
 def _verify_dict_keys(expected_keys, target_dict, strict=True):
diff --git a/neutron_lib/api/validators/dns.py b/neutron_lib/api/validators/dns.py
index db22c0f13..e93343cdb 100644
--- a/neutron_lib/api/validators/dns.py
+++ b/neutron_lib/api/validators/dns.py
@@ -61,7 +61,7 @@ def _validate_dns_name_with_dns_domain(request_dns_name, dns_domain):
     # legal size
     higher_labels = dns_domain
     if dns_domain:
-        higher_labels = '.%s' % dns_domain
+        higher_labels = f'.{dns_domain}'
     higher_labels_len = len(higher_labels)
     dns_name_len = len(request_dns_name)
     if not request_dns_name.endswith('.'):
@@ -97,7 +97,7 @@ def _get_dns_domain_config():
         return ''
     if cfg.CONF.dns_domain.endswith('.'):
         return cfg.CONF.dns_domain
-    return '%s.' % cfg.CONF.dns_domain
+    return f'{cfg.CONF.dns_domain}.'
 
 
 def _get_request_dns_name(dns_name):
diff --git a/neutron_lib/callbacks/exceptions.py b/neutron_lib/callbacks/exceptions.py
index bcbf8e6ee..ec96a4b9a 100644
--- a/neutron_lib/callbacks/exceptions.py
+++ b/neutron_lib/callbacks/exceptions.py
@@ -56,8 +56,7 @@ class NotificationError:
         self._cancellable = cancellable
 
     def __str__(self):
-        return 'Callback {} failed with "{}"'.format(
-            self.callback_id, self.error)
+        return f'Callback {self.callback_id} failed with "{self.error}"'
 
     @property
     def is_cancellable(self):
diff --git a/neutron_lib/callbacks/manager.py b/neutron_lib/callbacks/manager.py
index 0940a678b..93df91631 100644
--- a/neutron_lib/callbacks/manager.py
+++ b/neutron_lib/callbacks/manager.py
@@ -102,7 +102,7 @@ class CallbacksManager:
                 if not self._index[callback_id]:
                     del self._index[callback_id]
         else:
-            value = '{},{}'.format(resource, event)
+            value = f'{resource},{event}'
             raise exceptions.Invalid(element='resource,event', value=value)
 
     def unsubscribe_by_resource(self, callback, resource):
diff --git a/neutron_lib/callbacks/registry.py b/neutron_lib/callbacks/registry.py
index a618a124c..9701529a6 100644
--- a/neutron_lib/callbacks/registry.py
+++ b/neutron_lib/callbacks/registry.py
@@ -67,7 +67,7 @@ def receives(resource, events, priority=priority_group.PRIORITY_DEFAULT):
     @has_registry_receivers decorator to setup the __new__ method to
     actually register the instance methods after initialization.
     """
-    if not isinstance(events, (list, tuple, set)):
+    if not isinstance(events, list | tuple | set):
         msg = _("'events' must be a collection (list, tuple, set)")
         raise AssertionError(msg)
 
diff --git a/neutron_lib/constants.py b/neutron_lib/constants.py
index 802df1542..dd829472e 100644
--- a/neutron_lib/constants.py
+++ b/neutron_lib/constants.py
@@ -421,6 +421,7 @@ TC_QDISC_PARENTS = {'root': 0xffffffff,
 
 class Sentinel:
     """A constant object that does not change even when copied."""
+
     def __deepcopy__(self, memo):
         # Always return the same object because this is essentially a constant.
         return self
diff --git a/neutron_lib/db/api.py b/neutron_lib/db/api.py
index 114a60a67..f72bb3917 100644
--- a/neutron_lib/db/api.py
+++ b/neutron_lib/db/api.py
@@ -142,7 +142,7 @@ def _tag_retriables_as_unretriable(f):
 
 def _copy_if_lds(item):
     """Deepcopy lists/dicts/sets, leave everything else alone."""
-    return copy.deepcopy(item) if isinstance(item, (list, dict, set)) else item
+    return copy.deepcopy(item) if isinstance(item, list | dict | set) else item
 
 
 _retry_db_errors = oslo_db_api.wrap_db_retry(
@@ -338,8 +338,8 @@ def _load_one_to_manys(session):
             if relationship_attr.key not in state.dict:
                 getattr(new_object, relationship_attr.key)
                 if relationship_attr.key not in state.dict:
-                    msg = ("Relationship %s attributes must be loaded in db "
-                           "object %s" % (relationship_attr.key, state.dict))
+                    msg = (f"Relationship {relationship_attr.key} attributes "
+                           f"must be loaded in db object {state.dict}")
                     raise AssertionError(msg)
 
 
@@ -448,7 +448,7 @@ def _listen_for_changes(cls, key, inst):
         # can look up the parent.  so here we make one if it doesn't
         # have it already, as is the case in this example
         if not prop.back_populates:
-            name = "_%s_backref" % prop.key
+            name = f"_{prop.key}_backref"
             backref_prop = orm.relationship(
                 prop.parent, back_populates=prop.key)
 
diff --git a/neutron_lib/db/model_base.py b/neutron_lib/db/model_base.py
index 3846f129c..f1cc1757f 100644
--- a/neutron_lib/db/model_base.py
+++ b/neutron_lib/db/model_base.py
@@ -94,7 +94,7 @@ class _NeutronBase(models.ModelBase):
 
     def __repr__(self):
         """sqlalchemy based automatic __repr__ method."""
-        items = ['{}={!r}'.format(col.name, getattr(self, col.name))
+        items = [f'{col.name}={getattr(self, col.name)!r}'
                  for col in self.__table__.columns]
         return "<{}.{}[object at {:x}] {{{}}}>".format(
             self.__class__.__module__, self.__class__.__name__,
diff --git a/neutron_lib/db/model_query.py b/neutron_lib/db/model_query.py
index b8fe6f89c..60d33c040 100644
--- a/neutron_lib/db/model_query.py
+++ b/neutron_lib/db/model_query.py
@@ -90,7 +90,7 @@ def register_hook(model, name, query_hook, filter_hook,
     if callable(result_filters):
         result_filters = helpers.make_weak_ref(result_filters)
     if rbac_actions is not None:
-        if isinstance(rbac_actions, (set, list, tuple)):
+        if isinstance(rbac_actions, set | list | tuple):
             rbac_actions = set(rbac_actions)
         else:
             rbac_actions = {rbac_actions}
diff --git a/neutron_lib/db/utils.py b/neutron_lib/db/utils.py
index 70a4be33d..d8d9ee005 100644
--- a/neutron_lib/db/utils.py
+++ b/neutron_lib/db/utils.py
@@ -125,7 +125,7 @@ def get_marker_obj(plugin, context, resource, limit, marker):
         are given.
     """
     if limit and marker:
-        return getattr(plugin, '_get_%s' % resource)(context, marker)
+        return getattr(plugin, f'_get_{resource}')(context, marker)
 
 
 def resource_fields(resource, fields):
diff --git a/neutron_lib/exceptions/__init__.py b/neutron_lib/exceptions/__init__.py
index b598d7d21..a1a1f8e9f 100644
--- a/neutron_lib/exceptions/__init__.py
+++ b/neutron_lib/exceptions/__init__.py
@@ -396,6 +396,7 @@ class SubnetMismatchForPort(BadRequest):
 
 class Invalid(NeutronException):
     """A generic base class for invalid errors."""
+
     def __init__(self, message=None):
         self.message = message
         super().__init__()
diff --git a/neutron_lib/hacking/checks.py b/neutron_lib/hacking/checks.py
index 8b3d63359..febb6a35e 100644
--- a/neutron_lib/hacking/checks.py
+++ b/neutron_lib/hacking/checks.py
@@ -71,7 +71,7 @@ def use_jsonutils(logical_line, filename):
     if "json." in logical_line:
         json_funcs = ['dumps(', 'dump(', 'loads(', 'load(']
         for f in json_funcs:
-            pos = logical_line.find('json.%s' % f)
+            pos = logical_line.find(f'json.{f}')
             if pos != -1:
                 yield (pos, msg % {'fun': f[:-1]})
 
@@ -85,25 +85,25 @@ def _check_imports(regex, submatch, logical_line):
 def _check_namespace_imports(failure_code, namespace, new_ns, logical_line,
                              message_override=None):
     if message_override is not None:
-        msg_o = "{}: {}".format(failure_code, message_override)
+        msg_o = f"{failure_code}: {message_override}"
     else:
         msg_o = None
 
     if _check_imports(namespace_imports_from_dot, namespace, logical_line):
-        msg = ("%s: '%s' must be used instead of '%s'.") % (
+        msg = ("{}: '{}' must be used instead of '{}'.").format(
             failure_code,
-            logical_line.replace('%s.' % namespace, new_ns),
+            logical_line.replace(f'{namespace}.', new_ns),
             logical_line)
         return (0, msg_o or msg)
     elif _check_imports(namespace_imports_from_root, namespace, logical_line):
-        msg = ("%s: '%s' must be used instead of '%s'.") % (
+        msg = ("{}: '{}' must be used instead of '{}'.").format(
             failure_code,
             logical_line.replace(
-                'from %s import ' % namespace, 'import %s' % new_ns),
+                f'from {namespace} import ', f'import {new_ns}'),
             logical_line)
         return (0, msg_o or msg)
     elif _check_imports(namespace_imports_dot, namespace, logical_line):
-        msg = ("%s: '%s' must be used instead of '%s'.") % (
+        msg = ("{}: '{}' must be used instead of '{}'.").format(
             failure_code,
             logical_line.replace('import', 'from').replace('.', ' import '),
             logical_line)
diff --git a/neutron_lib/objects/common_types.py b/neutron_lib/objects/common_types.py
index 1252065ed..c8d76d94a 100644
--- a/neutron_lib/objects/common_types.py
+++ b/neutron_lib/objects/common_types.py
@@ -55,6 +55,7 @@ class RangeConstrainedInteger(obj_fields.Integer):
 
 class IPNetworkPrefixLen(RangeConstrainedInteger):
     """IP network (CIDR) prefix length custom Enum"""
+
     def __init__(self, **kwargs):
         super().__init__(start=0, end=lib_constants.IPv6_BITS, **kwargs)
 
@@ -205,6 +206,7 @@ class IntegerEnum(obj_fields.Integer):
 
 class IPVersionEnum(IntegerEnum):
     """IP version integer Enum"""
+
     def __init__(self, **kwargs):
         super().__init__(
             valid_values=lib_constants.IP_ALLOWED_VERSIONS, **kwargs)
@@ -243,6 +245,7 @@ class EtherTypeEnumField(obj_fields.AutoTypedField):
 
 class IpProtocolEnum(obj_fields.Enum):
     """IP protocol number Enum"""
+
     def __init__(self, **kwargs):
         super().__init__(
             valid_values=list(
@@ -269,6 +272,7 @@ class MACAddress(obj_fields.FieldType):
     This custom field is different from the one provided by
     oslo.versionedobjects library: it uses netaddr.EUI type instead of strings.
     """
+
     def coerce(self, obj, attr, value):
         if not isinstance(value, netaddr.EUI):
             msg = _("Field value %s is not a netaddr.EUI") % value
@@ -340,6 +344,7 @@ class IPNetwork(obj_fields.FieldType):
     oslo.versionedobjects library: it does not reset string representation for
     the field.
     """
+
     def coerce(self, obj, attr, value):
         if not isinstance(value, netaddr.IPNetwork):
             msg = _("Field value %s is not a netaddr.IPNetwork") % value
diff --git a/neutron_lib/placement/client.py b/neutron_lib/placement/client.py
index 0fc2a3be6..52d0963fc 100644
--- a/neutron_lib/placement/client.py
+++ b/neutron_lib/placement/client.py
@@ -127,19 +127,19 @@ class NoAuthClient:
         raise ks_exc.HttpError
 
     def get(self, url, endpoint_filter, **kwargs):
-        return self.request('{}{}'.format(self.url, url), 'GET', **kwargs)
+        return self.request(f'{self.url}{url}', 'GET', **kwargs)
 
     def post(self, url, json, endpoint_filter, **kwargs):
-        return self.request('{}{}'.format(self.url, url), 'POST', body=json,
+        return self.request(f'{self.url}{url}', 'POST', body=json,
                             **kwargs)
 
     def put(self, url, json, endpoint_filter, **kwargs):
-        resp = self.request('{}{}'.format(self.url, url), 'PUT', body=json,
+        resp = self.request(f'{self.url}{url}', 'PUT', body=json,
                             **kwargs)
         return resp
 
     def delete(self, url, endpoint_filter, **kwargs):
-        return self.request('{}{}'.format(self.url, url), 'DELETE', **kwargs)
+        return self.request(f'{self.url}{url}', 'DELETE', **kwargs)
 
 
 class PlacementAPIClient:
@@ -277,7 +277,7 @@ class PlacementAPIClient:
         :returns: The updated resource provider.
         """
         # pylint: disable=raise-missing-from
-        url = '/resource_providers/%s' % resource_provider['uuid']
+        url = '/resource_providers/{}'.format(resource_provider['uuid'])
         # update does not tolerate if the uuid is repeated in the body
         update_body = resource_provider.copy()
         update_body.pop('uuid')
@@ -314,7 +314,7 @@ class PlacementAPIClient:
 
         :param resource_provider_uuid: UUID of the resource provider.
         """
-        url = '/resource_providers/%s' % resource_provider_uuid
+        url = f'/resource_providers/{resource_provider_uuid}'
         self._delete(url)
 
     @_check_placement_api_available
@@ -326,7 +326,7 @@ class PlacementAPIClient:
         :returns: The Resource Provider matching the UUID.
         """
         # pylint: disable=raise-missing-from
-        url = '/resource_providers/%s' % resource_provider_uuid
+        url = f'/resource_providers/{resource_provider_uuid}'
         try:
             return self._get(url).json()
         except ks_exc.NotFound:
@@ -377,7 +377,7 @@ class PlacementAPIClient:
             filters['in_tree'] = in_tree
         if uuid:
             filters['uuid'] = uuid
-        url = '{}?{}'.format(url, parse.urlencode(filters))
+        url = f'{url}?{parse.urlencode(filters)}'
         return self._get(url).json()
 
     @_check_placement_api_available
@@ -409,7 +409,7 @@ class PlacementAPIClient:
         :returns: The updated set of inventory records.
         """
         # pylint: disable=raise-missing-from
-        url = '/resource_providers/%s/inventories' % resource_provider_uuid
+        url = f'/resource_providers/{resource_provider_uuid}/inventories'
         body = {
             'resource_provider_generation': resource_provider_generation,
             'inventories': inventories
@@ -432,8 +432,7 @@ class PlacementAPIClient:
                                                    is not found.
         :returns: None.
         """
-        url = '/resource_providers/%s/inventories' % (
-            resource_provider_uuid)
+        url = f'/resource_providers/{resource_provider_uuid}/inventories'
         try:
             self._delete(url)
         except ks_exc.NotFound as e:
@@ -454,8 +453,8 @@ class PlacementAPIClient:
         :raises PlacementInventoryNotFound: No inventory of class.
         :returns: None.
         """
-        url = '/resource_providers/{}/inventories/{}'.format(
-            resource_provider_uuid, resource_class)
+        url = (f'/resource_providers/{resource_provider_uuid}'
+               f'/inventories/{resource_class}')
         try:
             self._delete(url)
         except ks_exc.NotFound as e:
@@ -481,8 +480,8 @@ class PlacementAPIClient:
                                             for a resource provider.
         :returns: The inventory of the resource class as a dict.
         """
-        url = '/resource_providers/{}/inventories/{}'.format(
-            resource_provider_uuid, resource_class)
+        url = (f'/resource_providers/{resource_provider_uuid}/'
+               f'inventories/{resource_class}')
         try:
             return self._get(url).json()
         except ks_exc.NotFound as e:
@@ -515,8 +514,8 @@ class PlacementAPIClient:
                                                              server side.
         :returns: The updated inventory of the resource class as a dict.
         """
-        url = '/resource_providers/{}/inventories/{}'.format(
-            resource_provider_uuid, resource_class)
+        url = (f'/resource_providers/{resource_provider_uuid}/'
+               f'inventories/{resource_class}')
         body = inventory
 
         try:
@@ -535,7 +534,7 @@ class PlacementAPIClient:
                            provider.
         :returns: All aggregates associated with the resource provider.
         """
-        url = '/resource_providers/%s/aggregates' % resource_provider_uuid
+        url = f'/resource_providers/{resource_provider_uuid}/aggregates'
         return self._put(url, aggregates).json()
 
     @_check_placement_api_available
@@ -549,7 +548,7 @@ class PlacementAPIClient:
                   generation.
         """
         # pylint: disable=raise-missing-from
-        url = '/resource_providers/%s/aggregates' % resource_provider_uuid
+        url = f'/resource_providers/{resource_provider_uuid}/aggregates'
         try:
             return self._get(url).json()
         except ks_exc.NotFound:
@@ -571,7 +570,7 @@ class PlacementAPIClient:
         :returns: Evaluates to True if the trait exists.
         """
         # pylint: disable=raise-missing-from
-        url = '/traits/%s' % name
+        url = f'/traits/{name}'
         try:
             return self._get(url)
         except ks_exc.NotFound:
@@ -584,7 +583,7 @@ class PlacementAPIClient:
         :param name: name of the trait to create.
         :returns: The Response object so you may access response headers.
         """
-        url = '/traits/%s' % (name)
+        url = f'/traits/{name}'
         return self._put(url, None)
 
     @_check_placement_api_available
@@ -596,7 +595,7 @@ class PlacementAPIClient:
         :returns: None.
         """
         # pylint: disable=raise-missing-from
-        url = '/traits/%s' % (name)
+        url = f'/traits/{name}'
         try:
             self._delete(url)
         except ks_exc.NotFound:
@@ -629,7 +628,7 @@ class PlacementAPIClient:
                   resource provider generation.
         """
         # pylint: disable=raise-missing-from
-        url = '/resource_providers/%s/traits' % (resource_provider_uuid)
+        url = f'/resource_providers/{resource_provider_uuid}/traits'
         body = {
             'resource_provider_generation': resource_provider_generation,
             'traits': traits
@@ -657,7 +656,7 @@ class PlacementAPIClient:
                   with the resource provider generation.
         """
         # pylint: disable=raise-missing-from
-        url = '/resource_providers/%s/traits' % (resource_provider_uuid)
+        url = f'/resource_providers/{resource_provider_uuid}/traits'
         try:
             return self._get(url).json()
         except ks_exc.NotFound:
@@ -675,7 +674,7 @@ class PlacementAPIClient:
         :returns: None.
         """
         # pylint: disable=raise-missing-from
-        url = '/resource_providers/%s/traits' % (resource_provider_uuid)
+        url = f'/resource_providers/{resource_provider_uuid}/traits'
         try:
             self._delete(url)
         except ks_exc.NotFound:
@@ -698,7 +697,7 @@ class PlacementAPIClient:
         :returns: The name of resource class and its set of links.
         """
         # pylint: disable=raise-missing-from
-        url = '/resource_classes/%s' % (name)
+        url = f'/resource_classes/{name}'
         try:
             return self._get(url).json()
         except ks_exc.NotFound:
@@ -722,7 +721,7 @@ class PlacementAPIClient:
         :param name: the name of the resource class to be updated or validated
         :returns: None.
         """
-        url = '/resource_classes/%s' % name
+        url = f'/resource_classes/{name}'
         self._put(url, None)
 
     @_check_placement_api_available
@@ -735,7 +734,7 @@ class PlacementAPIClient:
         :returns: None.
         """
         # pylint: disable=raise-missing-from
-        url = '/resource_classes/%s' % (name)
+        url = f'/resource_classes/{name}'
         try:
             self._delete(url)
         except ks_exc.NotFound:
@@ -749,7 +748,7 @@ class PlacementAPIClient:
                               owned by a VM, the VM uuid.
         :returns: All allocation records for the consumer.
         """
-        url = '/allocations/%s' % consumer_uuid
+        url = f'/allocations/{consumer_uuid}'
         return self._get(url).json()
 
     def update_qos_allocation(self, consumer_uuid, alloc_diff):
@@ -804,5 +803,5 @@ class PlacementAPIClient:
         :param allocations: Dict in the form described in placement API ref:
                             https://tinyurl.com/yxeuzn6l
         """
-        url = '/allocations/%s' % consumer_uuid
+        url = f'/allocations/{consumer_uuid}'
         self._put(url, allocations)
diff --git a/neutron_lib/placement/utils.py b/neutron_lib/placement/utils.py
index 7a12c9f38..3ee1b7b35 100644
--- a/neutron_lib/placement/utils.py
+++ b/neutron_lib/placement/utils.py
@@ -27,8 +27,8 @@ def physnet_trait(physnet):
     :param physnet: The physnet name.
     :returns: The trait name representing the physnet.
     """
-    return os_traits.normalize_name('{}{}'.format(
-        place_const.TRAIT_PREFIX_PHYSNET, physnet))
+    return os_traits.normalize_name(
+        f'{place_const.TRAIT_PREFIX_PHYSNET}{physnet}')
 
 
 def vnic_type_trait(vnic_type):
@@ -37,8 +37,8 @@ def vnic_type_trait(vnic_type):
     :param physnet: The vnic_type.
     :returns: The trait name representing the vnic_type.
     """
-    return os_traits.normalize_name('{}{}'.format(
-        place_const.TRAIT_PREFIX_VNIC_TYPE, vnic_type))
+    return os_traits.normalize_name(
+        f'{place_const.TRAIT_PREFIX_VNIC_TYPE}{vnic_type}')
 
 
 def six_uuid5(namespace, name):
diff --git a/neutron_lib/plugins/utils.py b/neutron_lib/plugins/utils.py
index 515ff847e..5401a15af 100644
--- a/neutron_lib/plugins/utils.py
+++ b/neutron_lib/plugins/utils.py
@@ -288,9 +288,9 @@ def get_interface_name(name, prefix='', max_len=constants.DEVICE_NAME_MAX_LEN):
     namelen = max_len - len(prefix) - INTERFACE_HASH_LEN
     hashed_name = hashlib.new('sha1', usedforsecurity=False)
     hashed_name.update(encodeutils.to_utf8(name))
-    new_name = ('%(prefix)s%(truncated)s%(hash)s' %
-                {'prefix': prefix, 'truncated': name[0:namelen],
-                 'hash': hashed_name.hexdigest()[0:INTERFACE_HASH_LEN]})
+    new_name = (
+        f'{prefix}{name[0:namelen]}'
+        f'{hashed_name.hexdigest()[0:INTERFACE_HASH_LEN]}')
     LOG.info("The requested interface name %(requested_name)s exceeds the "
              "%(limit)d character limitation. It was shortened to "
              "%(new_name)s to fit.",
diff --git a/neutron_lib/rpc.py b/neutron_lib/rpc.py
index 507739946..316df0b89 100644
--- a/neutron_lib/rpc.py
+++ b/neutron_lib/rpc.py
@@ -139,8 +139,8 @@ class _BackingOffContextWrapper(_ContextWrapper):
         # two methods with the same name in different namespaces should
         # be tracked independently
         if self._original_context.target.namespace:
-            scoped_method = '{}.{}'.format(
-                self._original_context.target.namespace, method)
+            scoped_method = (
+                f'{self._original_context.target.namespace}.{method}')
         else:
             scoped_method = method
         # set the timeout from the global method timeout tracker for this
@@ -181,6 +181,7 @@ class BackingOffClient(oslo_messaging.RPCClient):
     returned will track when call timeout exceptions occur and exponentially
     increase the timeout for the given call method.
     """
+
     def prepare(self, *args, **kwargs):
         ctx = super().prepare(*args, **kwargs)
         # don't back off contexts that explicitly set a timeout
@@ -245,7 +246,7 @@ def get_notifier(service=None, host=None, publisher_id=None):
                         "None. This is deprecated since 2025.1 release and "
                         "will be removed in one of the future releases. "
                         "Please always pass the 'service' argument.")
-        publisher_id = "{}.{}".format(service, host or cfg.CONF.host)
+        publisher_id = f"{service}.{host or cfg.CONF.host}"
     serializer = RequestContextSerializer()
     return oslo_messaging.Notifier(NOTIFICATION_TRANSPORT,
                                    serializer=serializer,
@@ -254,6 +255,7 @@ def get_notifier(service=None, host=None, publisher_id=None):
 
 class RequestContextSerializer(om_serializer.Serializer):
     """Convert RPC common context into Neutron Context."""
+
     def __init__(self, base=None):
         super().__init__()
         self._base = base
@@ -294,6 +296,7 @@ class Service(os_service.Service):
 
     A service enables rpc by listening to queues based on topic and host.
     """
+
     def __init__(self, host, topic, manager=None, serializer=None):
         super().__init__()
         self.host = host
@@ -328,7 +331,8 @@ class Service(os_service.Service):
         # errors, go ahead and ignore them.. as we're shutting down anyway
         try:
             self.conn.close()
-        except Exception:  # nosec
+        except Exception as e:
+            LOG.debug("Ignored exception during stop: %s", str(e))
             pass
         super().stop()
 
diff --git a/neutron_lib/tests/_base.py b/neutron_lib/tests/_base.py
index a0b46a853..2f79c13f2 100644
--- a/neutron_lib/tests/_base.py
+++ b/neutron_lib/tests/_base.py
@@ -110,7 +110,7 @@ class BaseTestCase(testtools.TestCase):
         if conf is None:
             version_info = pbr.version.VersionInfo('neutron-lib')
             cfg.CONF(args=args, project='neutron_lib',
-                     version='%%(prog)s %s' % version_info.release_string())
+                     version=f'%(prog)s {version_info.release_string()}')
         else:
             conf(args)
 
@@ -224,16 +224,18 @@ class BaseTestCase(testtools.TestCase):
         be reported upon failure.
         """
         if not isinstance(expected_subset, dict):
-            self.fail("expected_subset (%s) is not an instance of dict" %
-                      type(expected_subset))
+            self.fail(
+                f"expected_subset ({type(expected_subset)}) is not "
+                "an instance of dict")
         if not isinstance(actual_superset, dict):
-            self.fail("actual_superset (%s) is not an instance of dict" %
-                      type(actual_superset))
+            self.fail(
+                f"actual_superset ({type(actual_superset)}) is not "
+                "an instance of dict")
         for k, v in expected_subset.items():
             self.assertIn(k, actual_superset)
             self.assertEqual(v, actual_superset[k],
-                             "Key %(key)s expected: %(exp)r, actual %(act)r" %
-                             {'key': k, 'exp': v, 'act': actual_superset[k]})
+                             f"Key {k} expected: {v!r}, actual "
+                             f"{actual_superset[k]!r}")
 
     def setup_config(self, args=None):
         """Tests that need a non-default config can override this method."""
diff --git a/neutron_lib/tests/_post_mortem_debug.py b/neutron_lib/tests/_post_mortem_debug.py
index 6736d3ba0..f4658987c 100644
--- a/neutron_lib/tests/_post_mortem_debug.py
+++ b/neutron_lib/tests/_post_mortem_debug.py
@@ -26,13 +26,14 @@ def _get_debugger(debugger_name):
     try:
         debugger = __import__(debugger_name)
     except ImportError as exc:
-        raise ValueError("can't import %s module as a post mortem debugger" %
-                         debugger_name) from exc
+        raise ValueError(
+            f"can't import {debugger_name} module as a "
+            "post mortem debugger") from exc
     if 'post_mortem' in dir(debugger):
         return debugger
     else:
-        raise ValueError("%s is not a supported post mortem debugger" %
-                         debugger_name)
+        raise ValueError(
+            f"{debugger_name} is not a supported post mortem debugger")
 
 
 def _exception_handler(debugger, exc_info):
diff --git a/neutron_lib/tests/unit/api/definitions/base.py b/neutron_lib/tests/unit/api/definitions/base.py
index 41cc0d453..49d195d1f 100644
--- a/neutron_lib/tests/unit/api/definitions/base.py
+++ b/neutron_lib/tests/unit/api/definitions/base.py
@@ -13,7 +13,6 @@
 import importlib.util
 import os
 import types
-import typing
 
 from neutron_lib.api import definitions
 from neutron_lib.api.definitions import base
@@ -25,7 +24,7 @@ from neutron_lib.tests import _base as test_base
 def assert_bool(tester, attribute, attribute_dict, keyword, value):
     tester.assertIsInstance(
         value, bool,
-        '{} must be a boolean for {}.'.format(keyword, attribute))
+        f'{keyword} must be a boolean for {attribute}.')
 
 
 def assert_converter(tester, attribute, attribute_dict, keyword, value):
@@ -40,20 +39,19 @@ def assert_converter(tester, attribute, attribute_dict, keyword, value):
             attribute_dict['convert_list_to'](attribute_dict['default'])
         except KeyError:
             if validators.is_attr_set(value) and not isinstance(
-                    value, (str, list)):
-                tester.fail("Default value '%s' cannot be converted for "
-                            "attribute %s." % (value, attribute))
+                    value, str | list):
+                tester.fail(f"Default value '{value}' cannot be converted for "
+                            f"attribute {attribute}.")
 
 
 def assert_true(tester, attribute, attribute_dict, keyword, value):
     tester.assertTrue(
-        value, '{} must be True for {}.'.format(keyword, attribute))
+        value, f'{keyword} must be True for {attribute}.')
 
 
 def assert_validator(tester, attribute, attribute_dict, keyword, value):
     tester.assertIn(list(value)[0], validators.validators,
-                    '{} is not a known validator for {}.'.format(
-                        value, attribute))
+                    f'{value} is not a known validator for {attribute}.')
 
 
 ASSERT_FUNCTIONS = {
@@ -76,7 +74,7 @@ ASSERT_FUNCTIONS = {
 
 class DefinitionBaseTestCase(test_base.BaseTestCase):
 
-    extension_module: typing.Optional[types.ModuleType] = None
+    extension_module: types.ModuleType | None = None
     extension_resources: tuple[str, ...] = ()
     extension_subresources: tuple[str, ...] = ()
     extension_attributes: tuple[str, ...] = ()
diff --git a/neutron_lib/tests/unit/api/validators/test_dns.py b/neutron_lib/tests/unit/api/validators/test_dns.py
index 048997cd2..fac3e29d9 100644
--- a/neutron_lib/tests/unit/api/validators/test_dns.py
+++ b/neutron_lib/tests/unit/api/validators/test_dns.py
@@ -32,38 +32,37 @@ class TestDnsValidators(base.BaseTestCase):
 
         invalid_data = 'A' * 256
         max_len = 255
-        expected = ("'%(data)s' not a valid PQDN or FQDN. Reason: "
-                    "'%(data)s' exceeds the %(maxlen)s character FQDN "
-                    "limit") % {'data': invalid_data, 'maxlen': max_len}
+        expected = (f"'{invalid_data}' not a valid PQDN or FQDN. Reason: "
+                    f"'{invalid_data}' exceeds the {max_len} character FQDN "
+                    "limit")
         msg = dns.validate_dns_name(invalid_data, max_len)
         self.assertEqual(expected, msg)
 
         invalid_data = '.hostname'
-        expected = ("'%(data)s' not a valid PQDN or FQDN. Reason: "
-                    "Encountered an empty component") % {'data': invalid_data}
+        expected = (f"'{invalid_data}' not a valid PQDN or FQDN. Reason: "
+                    "Encountered an empty component")
         msg = dns.validate_dns_name(invalid_data)
         self.assertEqual(expected, msg)
 
         invalid_data = 'hostname-'
-        expected = ("'%(data)s' not a valid PQDN or FQDN. Reason: "
-                    "Name '%(data)s' must not start or end with a "
-                    "hyphen") % {'data': invalid_data}
+        expected = (f"'{invalid_data}' not a valid PQDN or FQDN. Reason: "
+                    f"Name '{invalid_data}' must not start or end with a "
+                    "hyphen")
         msg = dns.validate_dns_name(invalid_data)
         self.assertEqual(expected, msg)
 
         invalid_data = 'hostname@host'
-        expected = ("'%(data)s' not a valid PQDN or FQDN. Reason: "
-                    "Name '%(data)s' must be 1-63 characters long, each of "
-                    "which can only be alphanumeric or a "
-                    "hyphen") % {'data': invalid_data}
+        expected = (f"'{invalid_data}' not a valid PQDN or FQDN. Reason: "
+                    f"Name '{invalid_data}' must be 1-63 characters long, "
+                    "each of which can only be alphanumeric or a "
+                    "hyphen")
         msg = dns.validate_dns_name(invalid_data)
         self.assertEqual(expected, msg)
         invalid_suffix = '1234'
         invalid_data = 'hostname.' + invalid_suffix
-        expected = ("'%(data)s' not a valid PQDN or FQDN. Reason: "
-                    "TLD '%(suffix)s' must not be all "
-                    "numeric") % {'data': invalid_data,
-                                  'suffix': invalid_suffix}
+        expected = (f"'{invalid_data}' not a valid PQDN or FQDN. Reason: "
+                    f"TLD '{invalid_suffix}' must not be all "
+                    "numeric")
         msg = dns.validate_dns_name(invalid_data)
         self.assertEqual(expected, msg)
 
@@ -72,16 +71,13 @@ class TestDnsValidators(base.BaseTestCase):
         CONF.dns_domain = invalid_domain
         dns_name = 'hostname'
         expected = ("The dns_name passed is a PQDN and its size is "
-                    "'%(dns_name_len)s'. The dns_domain option in "
-                    "neutron.conf is set to %(dns_domain)s, with a "
-                    "length of '%(higher_labels_len)s'. When the two are "
+                    f"'{len(dns_name)}'. The dns_domain option in "
+                    f"neutron.conf is set to {invalid_domain}, with a "
+                    f"length of '{len(invalid_domain) + 1}'. When the two are "
                     "concatenated to form a FQDN (with a '.' at the end), "
                     "the resulting length exceeds the maximum size "
-                    "of '%(fqdn_max_len)s'"
-                    ) % {'dns_name_len': len(dns_name),
-                         'dns_domain': invalid_domain,
-                         'higher_labels_len': len(invalid_domain) + 1,
-                         'fqdn_max_len': db_constants.FQDN_FIELD_SIZE}
+                    f"of '{db_constants.FQDN_FIELD_SIZE}'"
+                    )
         msg = dns.validate_dns_name(dns_name)
         self.assertEqual(expected, msg)
 
@@ -90,9 +86,9 @@ class TestDnsValidators(base.BaseTestCase):
         CONF.dns_domain = dns_domain
         expected = ("The dns_name passed is a FQDN. Its higher level labels "
                     "must be equal to the dns_domain option in neutron.conf, "
-                    "that has been set to '%(dns_domain)s'. It must also "
+                    f"that has been set to '{dns_domain}'. It must also "
                     "include one or more valid DNS labels to the left "
-                    "of '%(dns_domain)s'") % {'dns_domain': dns_domain}
+                    f"of '{dns_domain}'")
         msg = dns.validate_dns_name(dns_name)
         self.assertEqual(expected, msg)
 
@@ -106,24 +102,22 @@ class TestDnsValidators(base.BaseTestCase):
         self.assertIsNone(msg)
 
         invalid_data = 1234
-        expected = "'%s' is not a valid string" % invalid_data
+        expected = f"'{invalid_data}' is not a valid string"
         msg = dns.validate_fip_dns_name(invalid_data)
         self.assertEqual(expected, msg)
 
         invalid_data = 'host.'
-        expected = ("'%s' is a FQDN. It should be a relative domain "
-                    "name") % invalid_data
+        expected = (f"'{invalid_data}' is a FQDN. It should be a relative "
+                    "domain name")
         msg = dns.validate_fip_dns_name(invalid_data)
         self.assertEqual(expected, msg)
 
         length = 10
         invalid_data = 'a' * length
         max_len = 12
-        expected = ("'%(data)s' contains %(length)s characters. Adding a "
+        expected = (f"'{invalid_data}' contains {length} characters. Adding a "
                     "domain name will cause it to exceed the maximum length "
-                    "of a FQDN of '%(max_len)s'") % {"data": invalid_data,
-                                                     "length": length,
-                                                     "max_len": max_len}
+                    f"of a FQDN of '{max_len}'")
         msg = dns.validate_fip_dns_name(invalid_data, max_len)
         self.assertEqual(expected, msg)
 
@@ -137,22 +131,20 @@ class TestDnsValidators(base.BaseTestCase):
         self.assertIsNone(msg)
 
         invalid_data = 1234
-        expected = "'%s' is not a valid string" % invalid_data
+        expected = f"'{invalid_data}' is not a valid string"
         msg = dns.validate_dns_domain(invalid_data)
         self.assertEqual(expected, msg)
 
         invalid_data = 'example.com'
-        expected = "'%s' is not a FQDN" % invalid_data
+        expected = f"'{invalid_data}' is not a FQDN"
         msg = dns.validate_dns_domain(invalid_data)
         self.assertEqual(expected, msg)
 
         length = 9
         invalid_data = 'a' * length + '.'
         max_len = 11
-        expected = ("'%(data)s' contains %(length)s characters. Adding a "
-                    "sub-domain will cause it to exceed the maximum length "
-                    "of a FQDN of '%(max_len)s'") % {"data": invalid_data,
-                                                     "length": length + 1,
-                                                     "max_len": max_len}
+        expected = (f"'{invalid_data}' contains {length + 1} characters. "
+                    "Adding a sub-domain will cause it to exceed the maximum "
+                    f"length of a FQDN of '{max_len}'")
         msg = dns.validate_dns_domain(invalid_data, max_len)
         self.assertEqual(expected, msg)
diff --git a/neutron_lib/tests/unit/api/validators/test_validators.py b/neutron_lib/tests/unit/api/validators/test_validators.py
index b2b5e45ae..9982273c9 100644
--- a/neutron_lib/tests/unit/api/validators/test_validators.py
+++ b/neutron_lib/tests/unit/api/validators/test_validators.py
@@ -149,9 +149,9 @@ class TestAttributeValidation(base.BaseTestCase):
         # Check that value is not comparable to valid_values and got Exception
         data = 1
         valid_values = '[2, 3, 4, 5]'
-        response = "'data' of type '%s' and 'valid_values' of type" \
-                   " '%s' are not compatible for comparison" % (
-                       type(data), type(valid_values))
+        response = (f"'data' of type '{type(data)}' and 'valid_values' of "
+                    f"type '{type(valid_values)}' are not compatible for "
+                    "comparison")
         self.assertRaisesRegex(TypeError, response,
                                validators.validate_values, data,
                                valid_values,
@@ -231,19 +231,19 @@ class TestAttributeValidation(base.BaseTestCase):
         max_len = 4
         msg = validators.validate_oneline_not_empty_string(data, max_len)
         self.assertEqual(
-            "'{}' exceeds maximum length of {}".format(data, max_len),
+            f"'{data}' exceeds maximum length of {max_len}",
             msg)
 
         data = "First line\nsecond line"
         msg = validators.validate_oneline_not_empty_string(data, None)
         self.assertEqual(
-            "Multi-line string is not allowed: '%s'" % data,
+            f"Multi-line string is not allowed: '{data}'",
             msg)
 
         data = ""
         msg = validators.validate_oneline_not_empty_string(data, None)
         self.assertEqual(
-            "'%s' Blank strings are not permitted" % data,
+            f"'{data}' Blank strings are not permitted",
             msg)
 
     def test_validate_oneline_not_empty_string_or_none(self):
@@ -260,19 +260,19 @@ class TestAttributeValidation(base.BaseTestCase):
         msg = validators.validate_oneline_not_empty_string_or_none(
             data, max_len)
         self.assertEqual(
-            "'{}' exceeds maximum length of {}".format(data, max_len),
+            f"'{data}' exceeds maximum length of {max_len}",
             msg)
 
         data = "First line\nsecond line"
         msg = validators.validate_oneline_not_empty_string_or_none(data, None)
         self.assertEqual(
-            "Multi-line string is not allowed: '%s'" % data,
+            f"Multi-line string is not allowed: '{data}'",
             msg)
 
         data = ""
         msg = validators.validate_oneline_not_empty_string(data, None)
         self.assertEqual(
-            "'%s' Blank strings are not permitted" % data,
+            f"'{data}' Blank strings are not permitted",
             msg)
 
     def test_validate_boolean(self):
@@ -325,10 +325,10 @@ class TestAttributeValidation(base.BaseTestCase):
         for ws in string.whitespace:
             self.assertRaises(n_exc.InvalidInput,
                               validators.validate_no_whitespace,
-                              '%swhitespace-at-head' % ws)
+                              f'{ws}whitespace-at-head')
             self.assertRaises(n_exc.InvalidInput,
                               validators.validate_no_whitespace,
-                              'whitespace-at-tail%s' % ws)
+                              f'whitespace-at-tail{ws}')
 
     def test_validate_range(self):
         msg = validators.validate_range(1, [1, 9])
@@ -426,35 +426,35 @@ class TestAttributeValidation(base.BaseTestCase):
 
         ip_addr = '1111.1.1.1'
         msg = validators.validate_ip_address(ip_addr)
-        self.assertEqual("'%s' is not a valid IP address" % ip_addr, msg)
+        self.assertEqual(f"'{ip_addr}' is not a valid IP address", msg)
 
         # Depending on platform to run UTs, this case might or might not be
         # an equivalent to test_validate_ip_address_bsd.
         ip_addr = '1' * 59
         msg = validators.validate_ip_address(ip_addr)
-        self.assertEqual("'%s' is not a valid IP address" % ip_addr, msg)
+        self.assertEqual(f"'{ip_addr}' is not a valid IP address", msg)
 
         ip_addr = '1.1.1.1 has whitespace'
         msg = validators.validate_ip_address(ip_addr)
-        self.assertEqual("'%s' is not a valid IP address" % ip_addr, msg)
+        self.assertEqual(f"'{ip_addr}' is not a valid IP address", msg)
 
         ip_addr = '111.1.1.1\twhitespace'
         msg = validators.validate_ip_address(ip_addr)
-        self.assertEqual("'%s' is not a valid IP address" % ip_addr, msg)
+        self.assertEqual(f"'{ip_addr}' is not a valid IP address", msg)
 
         ip_addr = '111.1.1.1\nwhitespace'
         msg = validators.validate_ip_address(ip_addr)
-        self.assertEqual("'%s' is not a valid IP address" % ip_addr, msg)
+        self.assertEqual(f"'{ip_addr}' is not a valid IP address", msg)
 
         for ws in string.whitespace:
-            ip_addr = '%s111.1.1.1' % ws
+            ip_addr = f'{ws}111.1.1.1'
             msg = validators.validate_ip_address(ip_addr)
-            self.assertEqual("'%s' is not a valid IP address" % ip_addr, msg)
+            self.assertEqual(f"'{ip_addr}' is not a valid IP address", msg)
 
         for ws in string.whitespace:
-            ip_addr = '111.1.1.1%s' % ws
+            ip_addr = f'111.1.1.1{ws}'
             msg = validators.validate_ip_address(ip_addr)
-            self.assertEqual("'%s' is not a valid IP address" % ip_addr, msg)
+            self.assertEqual(f"'{ip_addr}' is not a valid IP address", msg)
 
     def test_validate_ip_address_with_leading_zero(self):
         ip_addr = '1.1.1.01'
@@ -489,7 +489,7 @@ class TestAttributeValidation(base.BaseTestCase):
             msg = validators.validate_ip_address(ip_addr)
         ip_address_cls.assert_called_once_with(ip_addr,
                                                flags=netaddr.core.ZEROFILL)
-        self.assertEqual("'%s' is not a valid IP address" % ip_addr, msg)
+        self.assertEqual(f"'{ip_addr}' is not a valid IP address", msg)
 
     def test_validate_ip_pools(self):
         pools = [[{'end': '10.0.0.254'}],
@@ -517,7 +517,7 @@ class TestAttributeValidation(base.BaseTestCase):
         pools = [[{'end': '10.0.0.254', 'start': invalid_ip}]]
         for pool in pools:
             msg = validators.validate_ip_pools(pool)
-            self.assertEqual("'%s' is not a valid IP address" % invalid_ip,
+            self.assertEqual(f"'{invalid_ip}' is not a valid IP address",
                              msg)
 
     def test_validate_fixed_ips(self):
@@ -622,7 +622,7 @@ class TestAttributeValidation(base.BaseTestCase):
 
         ip_addr = '1111.1.1.1'
         msg = validators.validate_ip_address_or_none(ip_addr)
-        self.assertEqual("'%s' is not a valid IP address" % ip_addr, msg)
+        self.assertEqual(f"'{ip_addr}' is not a valid IP address", msg)
 
     def test_uuid_pattern(self):
         data = 'garbage'
@@ -718,37 +718,37 @@ class TestAttributeValidation(base.BaseTestCase):
         # Invalid - abbreviated ipv4 address
         cidr = "10/24"
         msg = validator(cidr, None)
-        error = "'%s' is not a valid IP subnet" % cidr
+        error = f"'{cidr}' is not a valid IP subnet"
         self.assertEqual(error, msg)
 
         # Invalid - IPv4 missing mask
         cidr = "10.0.2.0"
         msg = validator(cidr, None)
-        error = "'%s' is not a valid IP subnet" % cidr
+        error = f"'{cidr}' is not a valid IP subnet"
         self.assertEqual(error, msg)
 
         # Valid - IPv4 with non-zero masked bits is ok
         for i in range(1, 255):
-            cidr = "192.168.1.%s/24" % i
+            cidr = f"192.168.1.{i}/24"
             msg = validator(cidr, None)
             self.assertIsNone(msg)
 
         # Invalid - IPv6 without final octets, missing mask
         cidr = "fe80::"
         msg = validator(cidr, None)
-        error = "'%s' is not a valid IP subnet" % cidr
+        error = f"'{cidr}' is not a valid IP subnet"
         self.assertEqual(error, msg)
 
         # Invalid - IPv6 with final octets, missing mask
         cidr = "fe80::0"
         msg = validator(cidr, None)
-        error = "'%s' is not a valid IP subnet" % cidr
+        error = f"'{cidr}' is not a valid IP subnet"
         self.assertEqual(error, msg)
 
         # Invalid - Address format error
         cidr = 'invalid'
         msg = validator(cidr, None)
-        error = "'%s' is not a valid IP subnet" % cidr
+        error = f"'{cidr}' is not a valid IP subnet"
         self.assertEqual(error, msg)
 
         cidr = None
@@ -756,13 +756,13 @@ class TestAttributeValidation(base.BaseTestCase):
         if allow_none:
             self.assertIsNone(msg)
         else:
-            error = "'%s' is not a valid IP subnet" % cidr
+            error = f"'{cidr}' is not a valid IP subnet"
             self.assertEqual(error, msg)
 
         # Invalid - IPv4 with trailing CR
         cidr = "10.0.2.0/24\r"
         msg = validator(cidr, None)
-        error = "'%s' is not a valid IP subnet" % cidr
+        error = f"'{cidr}' is not a valid IP subnet"
         self.assertEqual(error, msg)
 
     def test_validate_subnet(self):
@@ -782,7 +782,7 @@ class TestAttributeValidation(base.BaseTestCase):
         # Invalid - CIDR
         cidr = "192.168.1.1/8"
         msg = validators.validate_route_cidr(cidr, None)
-        error = "'%s' is not a valid CIDR" % cidr
+        error = f"'{cidr}' is not a valid CIDR"
         self.assertEqual(error, msg)
 
         # Invalid - loopback CIDR
@@ -794,7 +794,7 @@ class TestAttributeValidation(base.BaseTestCase):
         # Invalid - CIDR format error
         cidr = 'invalid'
         msg = validators.validate_route_cidr(cidr, None)
-        error = "'%s' is not a valid CIDR" % cidr
+        error = f"'{cidr}' is not a valid CIDR"
         self.assertEqual(error, msg)
 
     def test_validate_subnet_or_none(self):
@@ -811,7 +811,7 @@ class TestAttributeValidation(base.BaseTestCase):
 
         cidrs = ['10.1.0.0/24', '10.2.0.0']
         msg = validators.validate_subnet_list(cidrs)
-        error = "'%s' is not a valid IP subnet" % cidrs[1]
+        error = f"'{cidrs[1]}' is not a valid IP subnet"
         self.assertEqual(error, msg)
 
     def _test_validate_regex(self, validator, allow_none=False):
@@ -826,7 +826,7 @@ class TestAttributeValidation(base.BaseTestCase):
 
         data = 'bat'
         msg = validator(data, pattern)
-        self.assertEqual("'%s' is not a valid input" % data, msg)
+        self.assertEqual(f"'{data}' is not a valid input", msg)
 
         data = 'hat'
         msg = validator(data, pattern)
@@ -881,7 +881,7 @@ class TestAttributeValidation(base.BaseTestCase):
                          'e5069610-744bb-42a7-8bd8-ceac1a229cd4']
         for uuid in invalid_uuids:
             msg = validators.validate_uuid(uuid)
-            error = "'%s' is not a valid UUID" % uuid
+            error = f"'{uuid}' is not a valid UUID"
             self.assertEqual(error, msg)
 
         msg = validators.validate_uuid('00000000-ffff-ffff-ffff-000000000000')
@@ -893,7 +893,7 @@ class TestAttributeValidation(base.BaseTestCase):
                          '123']
         msg = validators.validate_uuid_list(bad_uuid_list,
                                             valid_values='parameter not used')
-        error = "'%s' is not a valid UUID" % bad_uuid_list[2]
+        error = f"'{bad_uuid_list[2]}' is not a valid UUID"
         self.assertEqual(error, msg)
 
         good_uuid_list = ['00000000-ffff-ffff-ffff-000000000000',
@@ -911,7 +911,7 @@ class TestAttributeValidation(base.BaseTestCase):
                  {'uuid': 'e5069610-744b-42a7-8bd8-ceac1a229cd4'}]
         for item in items:
             msg = validators._validate_list_of_items(mock.Mock(), item)
-            error = "'%s' is not a list" % item
+            error = f"'{item}' is not a list"
             self.assertEqual(error, msg)
 
         # check duplicate items in a list
@@ -935,7 +935,7 @@ class TestAttributeValidation(base.BaseTestCase):
     def test__test__validate_list_of_items_non_empty(self):
         items = None
         msg = validators._validate_list_of_items_non_empty(mock.Mock(), items)
-        error = "'%s' is not a list" % items
+        error = f"'{items}' is not a list"
         self.assertEqual(error, msg)
 
         items = []
@@ -946,23 +946,23 @@ class TestAttributeValidation(base.BaseTestCase):
         items = ['a', 'b', 'duplicate_1', 'duplicate_2', 'duplicate_1',
                  'duplicate_2', 'duplicate_2', 'c']
         msg = validators._validate_list_of_items(mock.Mock(), items)
-        error = ("Duplicate items in the list: '%s'"
-                 % 'duplicate_1, duplicate_2')
+        error = ("Duplicate items in the list: '{}'".format(
+            'duplicate_1, duplicate_2'))
         self.assertEqual(error, msg)
 
         items = [['a', 'b'], ['c', 'd'], ['a', 'b']]
         msg = validators._validate_list_of_items(mock.Mock(), items)
-        error = "Duplicate items in the list: '%s'" % str(['a', 'b'])
+        error = "Duplicate items in the list: '{}'".format(str(['a', 'b']))
         self.assertEqual(error, msg)
 
         items = [{'a': 'b'}, {'c': 'd'}, {'a': 'b'}]
         msg = validators._validate_list_of_items(mock.Mock(), items)
-        error = "Duplicate items in the list: '%s'" % str({'a': 'b'})
+        error = "Duplicate items in the list: '{}'".format(str({'a': 'b'}))
         self.assertEqual(error, msg)
 
     def test_validate_dict_type(self):
         for value in (None, True, '1', []):
-            self.assertEqual("'%s' is not a dictionary" % value,
+            self.assertEqual(f"'{value}' is not a dictionary",
                              validators.validate_dict(value))
 
     def test_validate_dict_without_constraints(self):
@@ -1077,7 +1077,7 @@ class TestAttributeValidation(base.BaseTestCase):
         self.assertEqual("'abc' is not an integer", msg)
 
         for value in (-1, '-2'):
-            self.assertEqual("'%s' should be non-negative" % value,
+            self.assertEqual(f"'{value}' should be non-negative",
                              validators.validate_non_negative(value))
 
         for value in (0, 1, '2', True, False):
diff --git a/neutron_lib/tests/unit/callbacks/test_manager.py b/neutron_lib/tests/unit/callbacks/test_manager.py
index f0289192f..e77f0950f 100644
--- a/neutron_lib/tests/unit/callbacks/test_manager.py
+++ b/neutron_lib/tests/unit/callbacks/test_manager.py
@@ -95,8 +95,8 @@ class CallBacksManagerTestCase(base.BaseTestCase):
         self.assertIsNotNone(
             self.manager._callbacks[resources.PORT][events.BEFORE_CREATE])
         self.assertIn(callback_id_1, self.manager._index)
-        self.assertEqual(self.__module__ + '.callback_1-%s' %
-                         hash(callback_1), callback_id_1)
+        self.assertEqual(self.__module__ +
+                         f'.callback_1-{hash(callback_1)}', callback_id_1)
         self.assertEqual(cancellable,
                          self.manager._callbacks[resources.PORT]
                          [events.BEFORE_CREATE][0][2])
diff --git a/neutron_lib/tests/unit/db/test_api.py b/neutron_lib/tests/unit/db/test_api.py
index a106d5fb2..e224b4b77 100644
--- a/neutron_lib/tests/unit/db/test_api.py
+++ b/neutron_lib/tests/unit/db/test_api.py
@@ -172,26 +172,26 @@ class TestDeadLockDecorator(_base.BaseTestCase):
         context.session.is_active = False
         list_arg = [1, 2, 3, 4]
         dict_arg = {1: 'a', 2: 'b'}
-        l, d = self._context_function(context, list_arg, dict_arg,
-                                      5, db_exc.DBDeadlock())
+        la, da = self._context_function(context, list_arg, dict_arg,
+                                        5, db_exc.DBDeadlock())
         # even though we had 5 failures the list and dict should only
         # be mutated once
-        self.assertEqual(5, len(l))
-        self.assertEqual(3, len(d))
+        self.assertEqual(5, len(la))
+        self.assertEqual(3, len(da))
 
     def test_retry_if_session_inactive_kwargs_not_mutated_after_retries(self):
         context = mock.Mock()
         context.session.is_active = False
         list_arg = [1, 2, 3, 4]
         dict_arg = {1: 'a', 2: 'b'}
-        l, d = self._context_function(context, list_arg=list_arg,
-                                      dict_arg=dict_arg,
-                                      fail_count=5,
-                                      exc_to_raise=db_exc.DBDeadlock())
+        la, da = self._context_function(context, list_arg=list_arg,
+                                        dict_arg=dict_arg,
+                                        fail_count=5,
+                                        exc_to_raise=db_exc.DBDeadlock())
         # even though we had 5 failures the list and dict should only
         # be mutated once
-        self.assertEqual(5, len(l))
-        self.assertEqual(3, len(d))
+        self.assertEqual(5, len(la))
+        self.assertEqual(3, len(da))
 
     def test_retry_if_session_inactive_no_retry_in_active_session(self):
         context = mock.Mock()
diff --git a/neutron_lib/tests/unit/exceptions/test_l3_ext_ha_mode.py b/neutron_lib/tests/unit/exceptions/test_l3_ext_ha_mode.py
index 56eaa66c3..2150fcd9d 100644
--- a/neutron_lib/tests/unit/exceptions/test_l3_ext_ha_mode.py
+++ b/neutron_lib/tests/unit/exceptions/test_l3_ext_ha_mode.py
@@ -12,6 +12,7 @@
 
 from unittest import mock
 
+from neutron_lib._i18n import _
 import neutron_lib.exceptions.l3_ext_ha_mode as lehm
 from neutron_lib.tests.unit.exceptions import test_exceptions
 
diff --git a/neutron_lib/tests/unit/hacking/test_checks.py b/neutron_lib/tests/unit/hacking/test_checks.py
index f64c86a25..92a698aef 100644
--- a/neutron_lib/tests/unit/hacking/test_checks.py
+++ b/neutron_lib/tests/unit/hacking/test_checks.py
@@ -42,30 +42,30 @@ class HackingTestCase(base.BaseTestCase):
 
     def test_use_jsonutils(self):
         def __get_msg(fun):
-            msg = ("N521: jsonutils.%(fun)s must be used instead of "
-                   "json.%(fun)s" % {'fun': fun})
+            msg = (f"N521: jsonutils.{fun} must be used instead of "
+                   f"json.{fun}")
             return [(0, msg)]
 
         for method in ('dump', 'dumps', 'load', 'loads'):
             self.assertEqual(
                 __get_msg(method),
-                list(checks.use_jsonutils("json.%s(" % method,
+                list(checks.use_jsonutils(f"json.{method}(",
                                           "./neutron/common/rpc.py")))
 
             self.assertEqual(
                 0,
-                len(list(checks.use_jsonutils("jsonx.%s(" % method,
+                len(list(checks.use_jsonutils(f"jsonx.{method}(",
                                               "./neutron/common/rpc.py"))))
 
             self.assertEqual(
                 0,
-                len(list(checks.use_jsonutils("json.%sx(" % method,
+                len(list(checks.use_jsonutils(f"json.{method}x(",
                                               "./neutron/common/rpc.py"))))
 
             self.assertEqual(
                 0,
                 len(list(checks.use_jsonutils(
-                    "json.%s" % method,
+                    f"json.{method}",
                     "./neutron/plugins/ml2/drivers/openvswitch/agent/xenapi/"
                     "etc/xapi.d/plugins/netwrap"))))
 
@@ -100,15 +100,15 @@ class HackingTestCase(base.BaseTestCase):
     def test_no_log_translations(self):
         for log in tc._all_log_levels:
             for hint in tc._all_hints:
-                bad = 'LOG.{}({}("Bad"))'.format(log, hint)
+                bad = f'LOG.{log}({hint}("Bad"))'
                 self.assertEqual(
                     1, len(list(tc.no_translate_logs(bad, 'f'))))
                 # Catch abuses when used with a variable and not a literal
-                bad = 'LOG.{}({}(msg))'.format(log, hint)
+                bad = f'LOG.{log}({hint}(msg))'
                 self.assertEqual(
                     1, len(list(tc.no_translate_logs(bad, 'f'))))
                 # Do not do validations in tests
-                ok = 'LOG.%s(_("OK - unit tests"))' % log
+                ok = f'LOG.{log}(_("OK - unit tests"))'
                 self.assertEqual(
                     0, len(list(tc.no_translate_logs(ok, 'f/tests/f'))))
 
diff --git a/neutron_lib/tests/unit/objects/test_common_types.py b/neutron_lib/tests/unit/objects/test_common_types.py
index a29ea3300..ee9039329 100644
--- a/neutron_lib/tests/unit/objects/test_common_types.py
+++ b/neutron_lib/tests/unit/objects/test_common_types.py
@@ -74,7 +74,7 @@ class IPV6ModeEnumFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("'%s'" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"'{in_val}'", self.field.stringify(in_val))
 
 
 class DscpMarkFieldTest(test_base.BaseTestCase, TestField):
@@ -89,7 +89,7 @@ class DscpMarkFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("%s" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"{in_val}", self.field.stringify(in_val))
 
 
 class IPNetworkPrefixLenFieldTest(test_base.BaseTestCase, TestField):
@@ -103,7 +103,7 @@ class IPNetworkPrefixLenFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("%s" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"{in_val}", self.field.stringify(in_val))
 
 
 class MACAddressFieldTest(test_base.BaseTestCase, TestField):
@@ -126,7 +126,7 @@ class MACAddressFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual('%s' % in_val, self.field.stringify(in_val))
+            self.assertEqual(f'{in_val}', self.field.stringify(in_val))
 
 
 class IPNetworkFieldTest(test_base.BaseTestCase, TestField):
@@ -151,7 +151,7 @@ class IPNetworkFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual('%s' % in_val, self.field.stringify(in_val))
+            self.assertEqual(f'{in_val}', self.field.stringify(in_val))
 
 
 class IPVersionEnumFieldTest(test_base.BaseTestCase, TestField):
@@ -166,7 +166,7 @@ class IPVersionEnumFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("%s" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"{in_val}", self.field.stringify(in_val))
 
 
 class FlowDirectionEnumFieldTest(test_base.BaseTestCase, TestField):
@@ -181,7 +181,7 @@ class FlowDirectionEnumFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("'%s'" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"'{in_val}'", self.field.stringify(in_val))
 
 
 class FlowDirectionAndAnyEnumFieldTest(test_base.BaseTestCase, TestField):
@@ -196,7 +196,7 @@ class FlowDirectionAndAnyEnumFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("'%s'" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"'{in_val}'", self.field.stringify(in_val))
 
 
 class PortRangesFieldTest(test_base.BaseTestCase, TestField):
@@ -226,7 +226,7 @@ class DomainNameFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("'%s'" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"'{in_val}'", self.field.stringify(in_val))
 
 
 class EtherTypeEnumFieldTest(test_base.BaseTestCase, TestField):
@@ -241,7 +241,7 @@ class EtherTypeEnumFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("'%s'" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"'{in_val}'", self.field.stringify(in_val))
 
 
 class IpProtocolEnumFieldTest(test_base.BaseTestCase, TestField):
@@ -261,7 +261,7 @@ class IpProtocolEnumFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("'%s'" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"'{in_val}'", self.field.stringify(in_val))
 
 
 class UUIDFieldTest(test_base.BaseTestCase, TestField):
@@ -281,7 +281,7 @@ class UUIDFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual('%s' % in_val, self.field.stringify(in_val))
+            self.assertEqual(f'{in_val}', self.field.stringify(in_val))
 
 
 class DictOfMiscValuesFieldTest(test_base.BaseTestCase, TestField):
@@ -328,7 +328,7 @@ class NetworkSegmentRangeNetworkTypeEnumFieldTest(test_base.BaseTestCase,
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("'%s'" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"'{in_val}'", self.field.stringify(in_val))
 
 
 class NumaAffinityPoliciesEnumFieldTest(test_base.BaseTestCase, TestField):
@@ -346,7 +346,7 @@ class NumaAffinityPoliciesEnumFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("'%s'" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"'{in_val}'", self.field.stringify(in_val))
 
 
 class PortHardwareOffloadTypeEnumFieldTest(test_base.BaseTestCase, TestField):
@@ -361,4 +361,4 @@ class PortHardwareOffloadTypeEnumFieldTest(test_base.BaseTestCase, TestField):
 
     def test_stringify(self):
         for in_val, out_val in self.coerce_good_values:
-            self.assertEqual("'%s'" % in_val, self.field.stringify(in_val))
+            self.assertEqual(f"'{in_val}'", self.field.stringify(in_val))
diff --git a/neutron_lib/tests/unit/placement/test_client.py b/neutron_lib/tests/unit/placement/test_client.py
index 3064f2015..d61676147 100644
--- a/neutron_lib/tests/unit/placement/test_client.py
+++ b/neutron_lib/tests/unit/placement/test_client.py
@@ -64,17 +64,17 @@ class TestNoAuthClient(base.BaseTestCase):
 
     @mock.patch.object(place_client.NoAuthClient, 'request')
     def test_put(self, mock_request):
-        self.noauth_client.put('resource_providers/%s' % self.uuid,
+        self.noauth_client.put(f'resource_providers/{self.uuid}',
                                self.body_json, '')
         mock_request.assert_called_with(
-            'placement/resource_providers/%s' % self.uuid, 'PUT',
+            f'placement/resource_providers/{self.uuid}', 'PUT',
             body=self.body_json)
 
     @mock.patch.object(place_client.NoAuthClient, 'request')
     def test_delete(self, mock_request):
-        self.noauth_client.delete('resource_providers/%s' % self.uuid, '')
+        self.noauth_client.delete(f'resource_providers/{self.uuid}', '')
         mock_request.assert_called_with(
-            'placement/resource_providers/%s' % self.uuid, 'DELETE')
+            f'placement/resource_providers/{self.uuid}', 'DELETE')
 
 
 class TestPlacementAPIClientNoAuth(base.BaseTestCase):
@@ -127,7 +127,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
         self.placement_api_client.update_resource_provider(
             RESOURCE_PROVIDER)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_providers/%s' % RESOURCE_PROVIDER_UUID,
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}',
             {'name': RESOURCE_PROVIDER_NAME}
         )
 
@@ -135,7 +135,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
         self.placement_api_client.ensure_resource_provider(
             RESOURCE_PROVIDER)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_providers/%s' % RESOURCE_PROVIDER_UUID,
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}',
             {'name': RESOURCE_PROVIDER_NAME}
         )
         self.placement_fixture.mock_post.assert_not_called()
@@ -155,12 +155,12 @@ class TestPlacementAPIClient(base.BaseTestCase):
         self.placement_api_client.delete_resource_provider(
             RESOURCE_PROVIDER_UUID)
         self.placement_fixture.mock_delete.assert_called_once_with(
-            '/resource_providers/%s' % RESOURCE_PROVIDER_UUID)
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}')
 
     def test_get_resource_provider(self):
         self.placement_api_client.get_resource_provider(RESOURCE_PROVIDER_UUID)
         self.placement_fixture.mock_get.assert_called_once_with(
-            '/resource_providers/%s' % RESOURCE_PROVIDER_UUID)
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}')
 
     def test_get_resource_provider_no_resource_provider(self):
         self.placement_fixture.mock_get.side_effect = ks_exc.NotFound()
@@ -213,7 +213,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
         self.placement_api_client.update_resource_provider_inventories(
             RESOURCE_PROVIDER_UUID, INVENTORY, RESOURCE_PROVIDER_GENERATION)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_providers/%s/inventories' % RESOURCE_PROVIDER_UUID,
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/inventories',
             expected_body)
 
     def test_update_resource_provider_inventories_no_generation(self):
@@ -227,7 +227,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
             self.placement_api_client.update_resource_provider_inventories(
                 RESOURCE_PROVIDER_UUID, INVENTORY)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_providers/%s/inventories' % RESOURCE_PROVIDER_UUID,
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/inventories',
             expected_body)
 
     def test_update_resource_provider_inventories_no_rp(self):
@@ -243,9 +243,8 @@ class TestPlacementAPIClient(base.BaseTestCase):
             RESOURCE_PROVIDER_UUID, RESOURCE_CLASS_NAME
         )
         self.placement_fixture.mock_delete.assert_called_once_with(
-            '/resource_providers/%(rp_uuid)s/inventories/%(rc_name)s' %
-            {'rp_uuid': RESOURCE_PROVIDER_UUID,
-             'rc_name': RESOURCE_CLASS_NAME}
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/inventories/'
+            f'{RESOURCE_CLASS_NAME}'
         )
 
     def test_delete_resource_provider_inventory_no_rp(self):
@@ -263,9 +262,8 @@ class TestPlacementAPIClient(base.BaseTestCase):
         self.placement_api_client.get_inventory(RESOURCE_PROVIDER_UUID,
                                                 RESOURCE_CLASS_NAME)
         self.placement_fixture.mock_get.assert_called_once_with(
-            '/resource_providers/%(rp_uuid)s/inventories/%(rc_name)s' %
-            {'rp_uuid': RESOURCE_PROVIDER_UUID,
-             'rc_name': RESOURCE_CLASS_NAME})
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/inventories/'
+            f'{RESOURCE_CLASS_NAME}')
 
     def test_get_inventory_no_resource_provider(self):
         _exception = ks_exc.NotFound()
@@ -301,9 +299,8 @@ class TestPlacementAPIClient(base.BaseTestCase):
             RESOURCE_PROVIDER_UUID, INVENTORY, RESOURCE_CLASS_NAME,
             resource_provider_generation=1)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_providers/%(rp_uuid)s/inventories/%(rc_name)s' %
-            {'rp_uuid': RESOURCE_PROVIDER_UUID,
-             'rc_name': RESOURCE_CLASS_NAME},
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/inventories/'
+            f'{RESOURCE_CLASS_NAME}',
             expected_body)
 
     def test_update_resource_provider_inventory_no_generation(self):
@@ -317,9 +314,8 @@ class TestPlacementAPIClient(base.BaseTestCase):
             self.placement_api_client.update_resource_provider_inventory(
                 RESOURCE_PROVIDER_UUID, INVENTORY, RESOURCE_CLASS_NAME)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_providers/%(rp_uuid)s/inventories/%(rc_name)s' %
-            {'rp_uuid': RESOURCE_PROVIDER_UUID,
-             'rc_name': RESOURCE_CLASS_NAME},
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/inventories/'
+            f'{RESOURCE_CLASS_NAME}',
             expected_body)
 
     def test_update_resource_provider_inventory_not_found(self):
@@ -336,13 +332,13 @@ class TestPlacementAPIClient(base.BaseTestCase):
         self.placement_api_client.associate_aggregates(RESOURCE_PROVIDER_UUID,
                                                        mock.ANY)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_providers/%s/aggregates' % RESOURCE_PROVIDER_UUID,
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/aggregates',
             mock.ANY)
 
     def test_list_aggregates(self):
         self.placement_api_client.list_aggregates(RESOURCE_PROVIDER_UUID)
         self.placement_fixture.mock_get.assert_called_once_with(
-            '/resource_providers/%s/aggregates' % RESOURCE_PROVIDER_UUID)
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/aggregates')
 
     def test_list_aggregates_no_resource_provider(self):
         self.placement_fixture.mock_get.side_effect = ks_exc.NotFound()
@@ -358,7 +354,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
     def test_get_trait(self):
         self.placement_api_client.get_trait(TRAIT_NAME)
         self.placement_fixture.mock_get.assert_called_once_with(
-            '/traits/%s' % TRAIT_NAME)
+            f'/traits/{TRAIT_NAME}')
 
     def test_get_trait_no_trait(self):
         self.placement_fixture.mock_get.side_effect = ks_exc.NotFound()
@@ -370,7 +366,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
     def test_create_trait(self):
         self.placement_api_client.update_trait(TRAIT_NAME)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/traits/%s' % TRAIT_NAME, None)
+            f'/traits/{TRAIT_NAME}', None)
 
     def test_update_resource_provider_traits_generation(self):
         traits = [TRAIT_NAME]
@@ -378,8 +374,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
             RESOURCE_PROVIDER_UUID, traits,
             resource_provider_generation=RESOURCE_PROVIDER_GENERATION)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_providers/%(rp_uuid)s/traits' %
-            {'rp_uuid': RESOURCE_PROVIDER_UUID},
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/traits',
             {'resource_provider_generation': RESOURCE_PROVIDER_GENERATION,
              'traits': traits})
 
@@ -391,8 +386,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
             self.placement_api_client.update_resource_provider_traits(
                 RESOURCE_PROVIDER_UUID, traits)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_providers/%(rp_uuid)s/traits' %
-            {'rp_uuid': RESOURCE_PROVIDER_UUID},
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/traits',
             {'resource_provider_generation': RESOURCE_PROVIDER_GENERATION,
              'traits': traits})
 
@@ -416,7 +410,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
         self.placement_api_client.list_resource_provider_traits(
             RESOURCE_PROVIDER_UUID)
         self.placement_fixture.mock_get.assert_called_once_with(
-            '/resource_providers/%s/traits' % RESOURCE_PROVIDER_UUID)
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/traits')
 
     def test_list_resource_provider_traits_no_rp(self):
         self.placement_fixture.mock_get.side_effect = ks_exc.NotFound()
@@ -428,7 +422,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
     def test_delete_trait(self):
         self.placement_api_client.delete_trait(TRAIT_NAME)
         self.placement_fixture.mock_delete.assert_called_once_with(
-            '/traits/%s' % TRAIT_NAME)
+            f'/traits/{TRAIT_NAME}')
 
     def test_delete_trait_no_trait(self):
         self.placement_fixture.mock_delete.side_effect = ks_exc.NotFound()
@@ -441,7 +435,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
         self.placement_api_client.delete_resource_provider_traits(
             RESOURCE_PROVIDER_UUID)
         self.placement_fixture.mock_delete.assert_called_once_with(
-            '/resource_providers/%s/traits' % RESOURCE_PROVIDER_UUID)
+            f'/resource_providers/{RESOURCE_PROVIDER_UUID}/traits')
 
     def test_delete_resource_provider_traits_no_rp(self):
         self.placement_fixture.mock_delete.side_effect = ks_exc.NotFound()
@@ -459,7 +453,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
     def test_get_resource_class(self):
         self.placement_api_client.get_resource_class(RESOURCE_CLASS_NAME)
         self.placement_fixture.mock_get.assert_called_once_with(
-            '/resource_classes/%s' % RESOURCE_CLASS_NAME
+            f'/resource_classes/{RESOURCE_CLASS_NAME}'
         )
 
     def test_get_resource_class_no_resource_class(self):
@@ -480,12 +474,12 @@ class TestPlacementAPIClient(base.BaseTestCase):
     def test_update_resource_class(self):
         self.placement_api_client.update_resource_class(RESOURCE_CLASS_NAME)
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/resource_classes/%s' % RESOURCE_CLASS_NAME, None)
+            f'/resource_classes/{RESOURCE_CLASS_NAME}', None)
 
     def test_delete_resource_class(self):
         self.placement_api_client.delete_resource_class(RESOURCE_CLASS_NAME)
         self.placement_fixture.mock_delete.assert_called_once_with(
-            '/resource_classes/%s' % RESOURCE_CLASS_NAME
+            f'/resource_classes/{RESOURCE_CLASS_NAME}'
         )
 
     def test_delete_resource_class_no_resource_class(self):
@@ -704,7 +698,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
     def test_list_allocations(self):
         self.placement_api_client.list_allocations(CONSUMER_UUID)
         self.placement_fixture.mock_get.assert_called_once_with(
-            '/allocations/%s' % CONSUMER_UUID)
+            f'/allocations/{CONSUMER_UUID}')
 
     def test_update_allocation(self):
         mock_rsp = mock.Mock()
@@ -721,7 +715,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
                     'resources': {'a': 20}}
             }})
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/allocations/%s' % CONSUMER_UUID,
+            f'/allocations/{CONSUMER_UUID}',
             {'allocations': {
                 RESOURCE_PROVIDER_UUID: {
                     'resources': {'a': 20}}
@@ -744,7 +738,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
             alloc_diff={RESOURCE_PROVIDER_UUID: {'a': 2, 'b': 2}},
         )
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/allocations/%s' % CONSUMER_UUID,
+            f'/allocations/{CONSUMER_UUID}',
             {'allocations': {
                 RESOURCE_PROVIDER_UUID: {
                     'resources': {'a': 5, 'b': 4}}
@@ -834,7 +828,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
             alloc_diff={RESOURCE_PROVIDER_UUID: {'a': -3, 'b': -2}},
         )
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/allocations/%s' % CONSUMER_UUID,
+            f'/allocations/{CONSUMER_UUID}',
             {'allocations': {}})
 
     def test_update_qos_allocation_one_class_to_zero(self):
@@ -846,7 +840,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
             alloc_diff={RESOURCE_PROVIDER_UUID: {'a': -3, 'b': 1}},
         )
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/allocations/%s' % CONSUMER_UUID,
+            f'/allocations/{CONSUMER_UUID}',
             {'allocations': {
                 RESOURCE_PROVIDER_UUID: {
                     'resources': {'b': 3}}
@@ -861,7 +855,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
             alloc_diff={RESOURCE_PROVIDER_UUID: {'a': -3, 'b': 1}},
         )
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/allocations/%s' % CONSUMER_UUID,
+            f'/allocations/{CONSUMER_UUID}',
             {'allocations': {
                 RESOURCE_PROVIDER_UUID: {
                     'resources': {'b': 1}}
@@ -881,7 +875,7 @@ class TestPlacementAPIClient(base.BaseTestCase):
                 },
         )
         self.placement_fixture.mock_put.assert_called_once_with(
-            '/allocations/%s' % CONSUMER_UUID,
+            f'/allocations/{CONSUMER_UUID}',
             {'allocations': {
                 RESOURCE_PROVIDER_UUID: {
                     'resources': {'b': 4}},
diff --git a/neutron_lib/utils/helpers.py b/neutron_lib/utils/helpers.py
index 702bbcbd1..301b5fd31 100644
--- a/neutron_lib/utils/helpers.py
+++ b/neutron_lib/utils/helpers.py
@@ -97,7 +97,7 @@ def dict2str(dic):
     :returns: The dict in str representation that is a k=v command list for
         each item in dic.
     """
-    return ','.join("{}={}".format(key, val)
+    return ','.join(f"{key}={val}"
                     for key, val in sorted(dic.items()))
 
 
@@ -209,8 +209,7 @@ def resolve_ref(ref):
 
 def timecost(f):
     call_id = uuidutils.generate_uuid()
-    message_base = ("Time-cost: call %(call_id)s function %(fname)s ") % {
-                    "call_id": call_id, "fname": f.__name__}
+    message_base = (f"Time-cost: call {call_id} function {f.__name__} ")
     end_message = (message_base + "took %(seconds).3fs seconds to run")
 
     @timeutils.time_it(LOG, message=end_message, min_duration=None)
diff --git a/neutron_lib/utils/net.py b/neutron_lib/utils/net.py
index 85f6c8769..a39018bf0 100644
--- a/neutron_lib/utils/net.py
+++ b/neutron_lib/utils/net.py
@@ -42,7 +42,7 @@ def get_random_mac(base_mac):
            random.getrandbits(8), random.getrandbits(8)]
     if base_mac[3] != '00':
         mac[3] = int(base_mac[3], 16)
-    return ':'.join(["%02x" % x for x in mac])
+    return ':'.join([f"{x:02x}" for x in mac])
 
 
 def random_mac_generator(base_mac):
diff --git a/neutron_lib/utils/test.py b/neutron_lib/utils/test.py
index b6a7a92b4..2c7ac151a 100644
--- a/neutron_lib/utils/test.py
+++ b/neutron_lib/utils/test.py
@@ -27,8 +27,8 @@ def unstable_test(reason):
             try:
                 return f(self, *args, **kwargs)
             except Exception as e:
-                msg = ("%s was marked as unstable because of %s, "
-                       "failure was: %s") % (self.id(), reason, e)
+                msg = (f"{self.id()} was marked as unstable because of "
+                       f"{reason}, failure was: {e}")
                 raise self.skipTest(msg)
         return inner
     return decor
diff --git a/neutron_lib/worker.py b/neutron_lib/worker.py
index 5e8840779..1854475e0 100644
--- a/neutron_lib/worker.py
+++ b/neutron_lib/worker.py
@@ -93,9 +93,9 @@ class BaseWorker(service.ServiceBase):
         if not desc:
             desc = self.__class__.__name__
 
-        proctitle = "{}: {}".format(name, desc)
+        proctitle = f"{name}: {desc}"
         if self._set_proctitle == "on":
-            proctitle += " (%s)" % self._parent_proctitle
+            proctitle += f" ({self._parent_proctitle})"
 
         setproctitle.setproctitle(proctitle)
 
diff --git a/pyproject.toml b/pyproject.toml
index 7426e6ad0..cd82b157d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,3 +13,17 @@ disable_error_code = "import-untyped,var-annotated,import-not-found"
 # honor excludes by not following there through imports
 follow_imports = "silent"
 files = "neutron_lib"
+
+[tool.ruff]
+line-length = 79
+
+[tool.ruff.lint]
+select = ["E4", "E5", "E7", "E9", "F", "S", "UP"]
+ignore = [
+    "S104",  # Possible binding to all interfaces
+    "S311",  # Suspicious non-cryptographic random usage
+    "UP031", # Use format specifiers instead of percent format
+]
+
+[tool.ruff.lint.per-file-ignores]
+"neutron_lib/tests/*" = ["S"]