Run tox -e lint

.gitignore

@@ -79,3 +79,6 @@ venv
 .mypy_cache/
 .dmypy.json
 dmypy.json
+
+# ruff
+.ruff_cache

docs/conf.py

@@ -1,7 +1,7 @@
-import sys
+import datetime as dt
 import os
+import sys
 import time
-import datetime as dt
 
 import alabaster
 

examples/flask_example.py

@@ -3,7 +3,8 @@
 from flask import Flask, request
 from flask_sqlalchemy import SQLAlchemy
 from sqlalchemy.exc import NoResultFound
-from marshmallow import Schema, fields, ValidationError, pre_load
+
+from marshmallow import Schema, ValidationError, fields, pre_load
 
 app = Flask(__name__)
 app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:////tmp/quotes.db"

examples/package_json_example.py

@@ -1,9 +1,10 @@
-import sys
 import json
-from packaging import version
+import sys
 from pprint import pprint
 
-from marshmallow import Schema, fields, INCLUDE, ValidationError
+from packaging import version
+
+from marshmallow import INCLUDE, Schema, ValidationError, fields
 
 
 class Version(fields.Field):

examples/peewee_example.py

@@ -1,16 +1,17 @@
 import datetime as dt
 from functools import wraps
 
-from flask import Flask, request, g, jsonify
 import peewee as pw
+from flask import Flask, g, jsonify, request
+
 from marshmallow import (
     Schema,
+    ValidationError,
     fields,
-    validate,
-    pre_load,
     post_dump,
     post_load,
-    ValidationError,
+    pre_load,
+    validate,
 )
 
 app = Flask(__name__)

examples/textblob_example.py

@@ -1,5 +1,6 @@
-from bottle import route, request, run
+from bottle import request, route, run
 from textblob import TextBlob
+
 from marshmallow import Schema, fields
 
 

performance/benchmark.py

@@ -4,11 +4,11 @@
 """
 import argparse
 import cProfile
+import datetime
 import gc
 import timeit
-import datetime
 
-from marshmallow import Schema, fields, ValidationError, post_dump
+from marshmallow import Schema, ValidationError, fields, post_dump
 
 
 # Custom validator

pyproject.toml

@@ -65,6 +65,7 @@ show-fixes = true
 show-source = true
 
 [tool.ruff.lint]
+ignore = ["E203", "E266", "E501", "E731"]
 select = [
   "B",  # flake8-bugbear
   "E",  # pycodestyle error
@@ -74,6 +75,9 @@ select = [
   "W",  # pycodestyle warning
 ]
 
+[tool.ruff.per-file-ignores]
+"tests/*" = ["E721"]
+
 [tool.mypy]
 ignore_missing_imports = true
 warn_unreachable = true

src/marshmallow/__init__.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import importlib.metadata
+
 from packaging.version import Version
 
 from marshmallow.decorators import (

src/marshmallow/base.py

@@ -8,6 +8,7 @@
     Users should not need to use this module directly.
 """
 from __future__ import annotations
+
 from abc import ABC, abstractmethod
 
 

src/marshmallow/class_registry.py

@@ -10,6 +10,7 @@
 from __future__ import annotations
 
 import typing
+
 from marshmallow.exceptions import RegistryError
 
 if typing.TYPE_CHECKING:
@@ -76,16 +77,16 @@ def get_class(classname: str, all: bool = False) -> list[SchemaType] | SchemaTyp
         classes = _registry[classname]
     except KeyError as error:
         raise RegistryError(
-            "Class with name {!r} was not found. You may need "
-            "to import the class.".format(classname)
+            f"Class with name {classname!r} was not found. You may need "
+            "to import the class."
         ) from error
     if len(classes) > 1:
         if all:
             return _registry[classname]
         raise RegistryError(
-            "Multiple classes with name {!r} "
+            f"Multiple classes with name {classname!r} "
             "were found. Please use the full, "
-            "module-qualified path.".format(classname)
+            "module-qualified path."
         )
     else:
         return _registry[classname][0]

src/marshmallow/exceptions.py

@@ -3,7 +3,6 @@
 
 import typing
 
-
 # Key used for schema-level validation errors
 SCHEMA = "_schema"
 

src/marshmallow/fields.py

@@ -4,28 +4,30 @@
 import collections
 import copy
 import datetime as dt
-import numbers
-import uuid
-import ipaddress
 import decimal
+import ipaddress
 import math
+import numbers
 import typing
+import uuid
 import warnings
-from enum import Enum as EnumType
 from collections.abc import Mapping as _Mapping
+from enum import Enum as EnumType
 
-from marshmallow import validate, utils, class_registry, types
+from marshmallow import class_registry, types, utils, validate
 from marshmallow.base import FieldABC, SchemaABC
+from marshmallow.exceptions import (
+    FieldInstanceResolutionError,
+    StringNotCollectionError,
+    ValidationError,
+)
 from marshmallow.utils import (
+    is_aware,
     is_collection,
-    missing as missing_,
     resolve_field_instance,
-    is_aware,
 )
-from marshmallow.exceptions import (
-    ValidationError,
-    StringNotCollectionError,
-    FieldInstanceResolutionError,
+from marshmallow.utils import (
+    missing as missing_,
 )
 from marshmallow.validate import And, Length
 from marshmallow.warnings import RemovedInMarshmallow4Warning
@@ -237,14 +239,12 @@ def __init__(
 
     def __repr__(self) -> str:
         return (
-            "<fields.{ClassName}(dump_default={self.dump_default!r}, "
-            "attribute={self.attribute!r}, "
-            "validate={self.validate}, required={self.required}, "
-            "load_only={self.load_only}, dump_only={self.dump_only}, "
-            "load_default={self.load_default}, allow_none={self.allow_none}, "
-            "error_messages={self.error_messages})>".format(
-                ClassName=self.__class__.__name__, self=self
-            )
+            f"<fields.{self.__class__.__name__}(dump_default={self.dump_default!r}, "
+            f"attribute={self.attribute!r}, "
+            f"validate={self.validate}, required={self.required}, "
+            f"load_only={self.load_only}, dump_only={self.dump_only}, "
+            f"load_default={self.load_default}, allow_none={self.allow_none}, "
+            f"error_messages={self.error_messages})>"
         )
 
     def __deepcopy__(self, memo):
@@ -281,9 +281,9 @@ def make_error(self, key: str, **kwargs) -> ValidationError:
         except KeyError as error:
             class_name = self.__class__.__name__
             message = (
-                "ValidationError raised by `{class_name}`, but error key `{key}` does "
+                f"ValidationError raised by `{class_name}`, but error key `{key}` does "
                 "not exist in the `error_messages` dictionary."
-            ).format(class_name=class_name, key=key)
+            )
             raise AssertionError(message) from error
         if isinstance(msg, (str, bytes)):
             msg = msg.format(**kwargs)
@@ -297,9 +297,7 @@ def fail(self, key: str, **kwargs):
             Use `make_error <marshmallow.fields.Field.make_error>` instead.
         """
         warnings.warn(
-            '`Field.fail` is deprecated. Use `raise self.make_error("{}", ...)` instead.'.format(
-                key
-            ),
+            f'`Field.fail` is deprecated. Use `raise self.make_error("{key}", ...)` instead.',
             RemovedInMarshmallow4Warning,
             stacklevel=2,
         )
@@ -611,7 +609,7 @@ def schema(self):
                 elif not isinstance(nested, (str, bytes)):
                     raise ValueError(
                         "`Nested` fields must be passed a "
-                        "`Schema`, not {}.".format(nested.__class__)
+                        f"`Schema`, not {nested.__class__}."
                     )
                 elif nested == "self":
                     schema_class = self.root.__class__
@@ -1827,9 +1825,9 @@ def _serialize(self, value, attr, obj, **kwargs) -> str | None:
             return value.exploded
         return value.compressed
 
-    def _deserialize(
-        self, value, attr, data, **kwargs
-    ) -> None | (ipaddress.IPv4Interface | ipaddress.IPv6Interface):
+    def _deserialize(self, value, attr, data, **kwargs) -> None | (
+        ipaddress.IPv4Interface | ipaddress.IPv6Interface
+    ):
         if value is None:
             return None
         try:

src/marshmallow/schema.py

@@ -1,23 +1,21 @@
 """The :class:`Schema` class, including its metaclass and options (class Meta)."""
 from __future__ import annotations
-from abc import ABCMeta
 
-from collections import defaultdict, OrderedDict
-from collections.abc import Mapping
-from functools import lru_cache
+import copy
 import datetime as dt
-import uuid
 import decimal
-import copy
 import inspect
 import json
 import typing
+import uuid
 import warnings
+from abc import ABCMeta
+from collections import OrderedDict, defaultdict
+from collections.abc import Mapping
+from functools import lru_cache
 
-from marshmallow import base, fields as ma_fields, class_registry, types
-from marshmallow.error_store import ErrorStore
-from marshmallow.exceptions import ValidationError, StringNotCollectionError
-from marshmallow.orderedset import OrderedSet
+from marshmallow import base, class_registry, types
+from marshmallow import fields as ma_fields
 from marshmallow.decorators import (
     POST_DUMP,
     POST_LOAD,
@@ -26,15 +24,18 @@
     VALIDATES,
     VALIDATES_SCHEMA,
 )
+from marshmallow.error_store import ErrorStore
+from marshmallow.exceptions import StringNotCollectionError, ValidationError
+from marshmallow.orderedset import OrderedSet
 from marshmallow.utils import (
-    RAISE,
     EXCLUDE,
     INCLUDE,
-    missing,
-    set_value,
+    RAISE,
     get_value,
     is_collection,
     is_instance_or_subclass,
+    missing,
+    set_value,
     validate_unknown_parameter_value,
 )
 from marshmallow.warnings import RemovedInMarshmallow4Warning
@@ -407,9 +408,7 @@ def __init__(
         self.error_messages = messages
 
     def __repr__(self) -> str:
-        return "<{ClassName}(many={self.many})>".format(
-            ClassName=self.__class__.__name__, self=self
-        )
+        return f"<{self.__class__.__name__}(many={self.many})>"
 
     @property
     def dict_class(self) -> type:
@@ -1004,7 +1003,7 @@ def _init_fields(self) -> None:
                 "The data_key argument for one or more fields collides "
                 "with another field's name or data_key argument. "
                 "Check the following field names and "
-                "data_key arguments: {}".format(list(data_keys_duplicates))
+                f"data_key arguments: {list(data_keys_duplicates)}"
             )
         load_attributes = [obj.attribute or name for name, obj in load_fields.items()]
         if len(load_attributes) != len(set(load_attributes)):
@@ -1015,7 +1014,7 @@ def _init_fields(self) -> None:
                 "The attribute argument for one or more fields collides "
                 "with another field's name or attribute argument. "
                 "Check the following field names and "
-                "attribute arguments: {}".format(list(attributes_duplicates))
+                f"attribute arguments: {list(attributes_duplicates)}"
             )
 
         self.fields = fields_dict

src/marshmallow/utils.py

@@ -2,8 +2,8 @@
 from __future__ import annotations
 
 import collections
-import functools
 import datetime as dt
+import functools
 import inspect
 import json
 import re
@@ -311,10 +311,7 @@ def set_value(dct: dict[str, typing.Any], key: str, value: typing.Any):
         target = dct.setdefault(head, {})
         if not isinstance(target, dict):
             raise ValueError(
-                "Cannot set {key} in {head} "
-                "due to existing value: {target}".format(
-                    key=key, head=head, target=target
-                )
+                f"Cannot set {key} in {head} " f"due to existing value: {target}"
             )
         set_value(target, rest, value)
     else:

src/marshmallow/validate.py

@@ -27,9 +27,7 @@ def __repr__(self) -> str:
         args = self._repr_args()
         args = f"{args}, " if args else ""
 
-        return "<{self.__class__.__name__}({args}error={self.error!r})>".format(
-            self=self, args=args
-        )
+        return f"<{self.__class__.__name__}({args}error={self.error!r})>"
 
     def _repr_args(self) -> str:
         """A string representation of the args passed to this validator. Used by
@@ -237,7 +235,8 @@ class Email(Validator):
 
     DOMAIN_REGEX = re.compile(
         # domain
-        r"(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+" r"(?:[A-Z]{2,6}|[A-Z0-9-]{2,})\Z"
+        r"(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+"
+        r"(?:[A-Z]{2,6}|[A-Z0-9-]{2,})\Z"
         # literal form, ipv4 address (SMTP 4.1.3)
         r"|^\[(25[0-5]|2[0-4]\d|[0-1]?\d?\d)"
         r"(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\]\Z",