Replace remaining percent formatting with f-strings.

keyring/backends/SecretService.py

@@ -45,7 +45,7 @@ def priority(cls) -> float:
                         "activatable through D-Bus"
                     )
         except exceptions.SecretStorageException as e:
-            raise RuntimeError("Unable to initialize SecretService: %s" % e) from e
+            raise RuntimeError(f"Unable to initialize SecretService: {e}") from e
         return 5
 
     def get_preferred_collection(self):
@@ -60,7 +60,7 @@ def get_preferred_collection(self):
             else:
                 collection = secretstorage.get_default_collection(bus)
         except exceptions.SecretStorageException as e:
-            raise InitError("Failed to create the collection: %s." % e) from e
+            raise InitError(f"Failed to create the collection: {e}.") from e
         if collection.is_locked():
             collection.unlock()
             if collection.is_locked():  # User dismissed the prompt

keyring/backends/kwallet.py

@@ -96,7 +96,7 @@ def connected(self, service):
             self.iface = dbus.Interface(remote_obj, 'org.kde.KWallet')
             self.handle = self.iface.open(self.iface.networkWallet(), wId, self.appid)
         except dbus.DBusException as e:
-            raise InitError('Failed to open keyring: %s.' % e) from e
+            raise InitError(f'Failed to open keyring: {e}.') from e
 
         if self.handle < 0:
             return False

keyring/credentials.py

@@ -58,7 +58,7 @@ def _get_env(self, env_var):
         """Helper to read an environment variable"""
         value = os.environ.get(env_var)
         if not value:
-            raise ValueError('Missing environment variable:%s' % env_var)
+            raise ValueError(f'Missing environment variable:{env_var}')
         return value
 
     @property