Code quality improvements: modernize string formatting and fix linting issues

.pre-commit-config.yaml

@@ -68,7 +68,7 @@ repos:
       - id: rst-inline-touching-normal
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.15.22
+    rev: v0.16.1
     hooks:
       - id: ruff-check
         types_or: [python, jupyter]

docs/source/conf.py

@@ -23,7 +23,7 @@
 HERE = osp.abspath(osp.dirname(__file__))
 ROOT = osp.dirname(osp.dirname(HERE))
 
-from traitlets import __version__, version_info  # noqa: E402
+from traitlets import __version__, version_info
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the

pyproject.toml

@@ -232,6 +232,7 @@ ignore = [
   "E501",   # Line too long
   "S105", "S106",   # Possible hardcoded password
   "S110",   # S110 `try`-`except`-`pass` detected
+  "BLE001", # Do not catch blind exception: `Exception` (used deliberately for defensive fallbacks)
   "RUF012", # Mutable class attributes should be annotated with `typing.ClassVar`
   "ARG001", "ARG002",  # Unused function argument
   "RET503",  # Missing explicit `return` at the end of function

tests/config/test_application.py

@@ -488,23 +488,23 @@ def test_warn_autocorrect(self):
 
     def test_flatten_flags(self):
         cfg = Config()
-        cfg.MyApp.log_level = logging.WARN
+        cfg.MyApp.log_level = logging.WARNING
         app = MyApp()
         app.update_config(cfg)
-        self.assertEqual(app.log_level, logging.WARN)
-        self.assertEqual(app.config.MyApp.log_level, logging.WARN)
+        self.assertEqual(app.log_level, logging.WARNING)
+        self.assertEqual(app.config.MyApp.log_level, logging.WARNING)
         app.initialize(["--crit"])
         self.assertEqual(app.log_level, logging.CRITICAL)
         # this would be app.config.Application.log_level if it failed:
         self.assertEqual(app.config.MyApp.log_level, logging.CRITICAL)
 
     def test_flatten_aliases(self):
         cfg = Config()
-        cfg.MyApp.log_level = logging.WARN
+        cfg.MyApp.log_level = logging.WARNING
         app = MyApp()
         app.update_config(cfg)
-        self.assertEqual(app.log_level, logging.WARN)
-        self.assertEqual(app.config.MyApp.log_level, logging.WARN)
+        self.assertEqual(app.log_level, logging.WARNING)
+        self.assertEqual(app.config.MyApp.log_level, logging.WARNING)
         app.initialize(["--log-level", "CRITICAL"])
         self.assertEqual(app.log_level, logging.CRITICAL)
         # this would be app.config.Application.log_level if it failed:

tests/config/test_loader.py

@@ -536,7 +536,7 @@ def test_deepcopy(self):
         c1.Foo.bam = 30
         c1.a = "asdf"
         c1.b = range(10)
-        c1.Test.logger = logging.Logger("test")
+        c1.Test.logger = logging.Logger("test")  # noqa: LOG001
         c1.Test.get_logger = logging.getLogger("test")
         c2 = copy.deepcopy(c1)
         self.assertEqual(c1, c2)

tests/test_traitlets.py

@@ -2190,7 +2190,7 @@ def another_update(self, change):
                 self.i = change.new * 2
 
         mc = MyClass()
-        l = link((mc, "i"), (mc, "j"))  # noqa: E741
+        l = link((mc, "i"), (mc, "j"))
         self.assertRaises(TraitError, setattr, mc, "i", 2)
 
     def test_link_broken_at_target(self):
@@ -2203,7 +2203,7 @@ def another_update(self, change):
                 self.j = change.new * 2
 
         mc = MyClass()
-        l = link((mc, "i"), (mc, "j"))  # noqa: E741
+        l = link((mc, "i"), (mc, "j"))
         self.assertRaises(TraitError, setattr, mc, "j", 2)
 
 
@@ -2433,7 +2433,7 @@ class OrderTraits(HasTraits):
     i = Unicode()
     j = Unicode()
     k = Unicode()
-    l = Unicode()  # noqa: E741
+    l = Unicode()
 
     def _notify(self, name, old, new):
         """check the value of all traits when each trait change is triggered

tests/test_typing.py

@@ -215,7 +215,7 @@ def mypy_enum_typing() -> None:
     class T(HasTraits):
         log_level = Enum(
             (0, 10, 20, 30, 40, 50),
-            default_value=logging.WARN,
+            default_value=logging.WARNING,
             help="Set the log level by value or name.",
         ).tag(config=True)
 

traitlets/config/__init__.py

@@ -6,7 +6,7 @@
 from .configurable import *
 from .loader import Config
 
-__all__ = [  # noqa: F405
+__all__ = [
     "Application",
     "ApplicationError",
     "Config",

traitlets/config/application.py

@@ -134,7 +134,7 @@ class LevelFormatter(logging.Formatter):
     without adding 'INFO' to info, etc.
     """
 
-    highlevel_limit = logging.WARN
+    highlevel_limit = logging.WARNING
     highlevel_format = " %(levelname)s |"
 
     def format(self, record: logging.LogRecord) -> str:
@@ -204,7 +204,7 @@ def _classes_inc_parents(
     # The log level for the application
     log_level = Enum(
         (0, 10, 20, 30, 40, 50, "DEBUG", "INFO", "WARN", "ERROR", "CRITICAL"),
-        default_value=logging.WARN,
+        default_value=logging.WARNING,
         help="Set the log level by value or name.",
     ).tag(config=True)
 
@@ -717,7 +717,7 @@ def initialize_subcommand(self, subc: str, argv: ArgvType = None) -> None:
             # or ask factory to create it...
             self.subapp = subapp(self)
         else:
-            raise AssertionError(f"Invalid mappings for subcommand '{subc}'!")
+            raise TypeError(f"Invalid mappings for subcommand '{subc}'!")
 
         # ... and finally initialize subapp.
         self.subapp.initialize(argv)
@@ -757,7 +757,7 @@ def flatten_flags(self) -> tuple[dict[str, t.Any], dict[str, t.Any]]:
             if not isinstance(alias, tuple):  # type:ignore[unreachable]
                 alias = (alias,)  # type:ignore[assignment]
             for al in alias:
-                aliases[al] = ".".join([cls, trait])
+                aliases[al] = f"{cls}.{trait}"
 
         # flatten flags, which are of the form:
         # { 'key' : ({'Cls' : {'trait' : value}}, 'help')}
@@ -881,7 +881,7 @@ def parse_command_line(self, argv: ArgvType = None) -> None:
         loader = self._create_loader(argv, aliases, flags, classes=classes)
         try:
             self.cli_config = deepcopy(loader.load_config())
-        except SystemExit:
+        except SystemExit:  # noqa: TRY203
             # traitlets 5: no longer print help output on error
             # help output is huge, and comes after the error
             raise

traitlets/traitlets.py

@@ -1494,7 +1494,7 @@ def hold(change: Bunch) -> None:
                     trait = getattr(self.__class__, name)
                     value = trait._cross_validate(self, getattr(self, name))
                     self.set_trait(name, value)
-            except TraitError as e:
+            except TraitError:
                 # Roll back in case of TraitError during final cross validation.
                 self.notify_change = lambda x: None  # type:ignore[method-assign, assignment]  # noqa: ARG005
                 for name, changes in cache.items():
@@ -1506,7 +1506,7 @@ def hold(change: Bunch) -> None:
                             else:
                                 self._trait_values.pop(name)
                 cache = {}
-                raise e
+                raise
             finally:
                 self._cross_validation_lock = False
                 # Restore method retrieval from class
@@ -2024,8 +2024,8 @@ class Type(ClassBasedTraitType[G, S]):
         @t.overload
         def __init__(
             self: Type[type, type],
-            default_value: Sentinel | None | str = ...,
-            klass: None | str = ...,
+            default_value: Sentinel | str | None = ...,
+            klass: str | None = ...,
             allow_none: Literal[False] = ...,
             read_only: bool | None = ...,
             help: str | None = ...,
@@ -2036,8 +2036,8 @@ def __init__(
         @t.overload
         def __init__(
             self: Type[type | None, type | None],
-            default_value: Sentinel | None | str = ...,
-            klass: None | str = ...,
+            default_value: Sentinel | str | None = ...,
+            klass: str | None = ...,
             allow_none: Literal[True] = ...,
             read_only: bool | None = ...,
             help: str | None = ...,
@@ -2345,7 +2345,7 @@ def _resolve_string(self, string: str) -> t.Any:
         our this_class attribute was defined.
         """
         modname = self.this_class.__module__  # type:ignore[attr-defined]
-        return import_item(".".join([modname, string]))
+        return import_item(f"{modname}.{string}")
 
 
 class ForwardDeclaredType(ForwardDeclaredMixin, Type[G, S]):
@@ -4138,7 +4138,7 @@ def __init__(
         @t.overload
         def __init__(
             self: TCPAddress[tuple[str, int] | None, tuple[str, int] | None],
-            default_value: bool | None | Sentinel = ...,
+            default_value: bool | Sentinel | None = ...,
             allow_none: Literal[True] = ...,
             read_only: bool | None = ...,
             help: str | None = ...,
@@ -4149,7 +4149,7 @@ def __init__(
         def __init__(
             self: TCPAddress[tuple[str, int] | None, tuple[str, int] | None]
             | TCPAddress[tuple[str, int], tuple[str, int]],
-            default_value: bool | None | Sentinel = Undefined,
+            default_value: bool | Sentinel | None = Undefined,
             allow_none: Literal[True, False] = False,
             read_only: bool | None = None,
             help: str | None = None,

traitlets/utils/text.py

@@ -29,7 +29,7 @@ def _dedent(text: str) -> str:
     first, rest = splits
     # dedent everything but the first line
     rest = textwrap.dedent(rest)
-    return "\n".join([first, rest])
+    return f"{first}\n{rest}"
 
 
 def wrap_paragraphs(text: str, ncols: int = 80) -> list[str]: