👨‍💻 Explicitly (re-)export in the package __init__.py (including marshmallow exports)

.gitignore

@@ -21,5 +21,5 @@ __pycache__/
 # Testing:
 /.coverage
 
-# mypy:
-.mypy_cache/
+# Miscellaneous cache:
+.cache/

docs/index.md

@@ -10,19 +10,18 @@
 
 ---
 
-Extension for <a href="https://github.com/marshmallow-code/marshmallow" target="_blank">`marshmallow`</a> to make <a href="https://marshmallow.readthedocs.io/en/stable/quickstart.html#deserializing-to-objects" target="_blank">deserialization to objects</a> easier and improve type safety.
+Extension for <a href="https://github.com/marshmallow-code/marshmallow" target="_blank">**`marshmallow`**</a> to make <a href="https://marshmallow.readthedocs.io/en/stable/quickstart.html#deserializing-to-objects" target="_blank">deserialization to objects</a> easier and improve type safety.
 
 The main `GenericSchema` class extends <a href="https://marshmallow.readthedocs.io/en/stable/marshmallow.schema.html#marshmallow.schema.Schema" target="_blank">`marshmallow.Schema`</a> making it **generic** in terms of the class that data should be deserialized to, when calling <a href="https://marshmallow.readthedocs.io/en/stable/marshmallow.schema.html#marshmallow.schema.Schema.load" target="_blank">`load`/`loads`</a>.
 
 With `GenericSchema` there is no need to explicitly write `post_load` hooks to initialize the object anymore. 🎉
 
-If the "model" class is (for example) `User`, it just needs to be passed as the type argument, when subclassing `GenericSchema`. Depending on whether `many` is `True` or not, the output of the `load`/`loads` method will then be automatically inferred as either `User` or `list[User]` by any competent type checker. ✨
+If the "model" class is (for example) `User`, it just needs to be passed as the type argument, when subclassing `GenericSchema`. The output of the `load`/`loads` method will then be automatically inferred as either `User` or `list[User]` (depending on whether `many` is `True` or not) by any competent type checker. ✨
 
 ## Usage Example
 
 ```python
-from marshmallow import fields
-from marshmallow_generic import GenericSchema
+from marshmallow_generic import GenericSchema, fields
 
 
 class User:

pyproject.toml

@@ -65,6 +65,7 @@ version = {attr = "marshmallow_generic.__version__"}
 # Static type checking: #
 
 [tool.mypy]
+cache_dir = ".cache/mypy"
 files = [
     "src/",
     "tests/",
@@ -80,6 +81,7 @@ plugins = [
 # Unit test coverage: #
 
 [tool.coverage.run]
+data_file = ".cache/coverage"
 source = [
     "src/",
 ]
@@ -105,6 +107,7 @@ omit = [
 # Linting and style checking: #
 
 [tool.ruff]
+cache-dir = ".cache/ruff"
 select = [
     "E",   # pycodestyle errors
     "W",   # pycodestyle warnings

src/marshmallow_generic/__init__.py

@@ -19,5 +19,41 @@ __doc__ = """
 Generic schema with full typing support and minimal boilerplate.
 """
 
-from .decorators import post_load
-from .schema import GenericSchema
+__all__ = [
+    # Custom:
+    "GenericSchema",
+    "post_load",
+    # Re-exports from marshmallow:
+    "EXCLUDE",
+    "INCLUDE",
+    "RAISE",
+    "Schema",
+    "SchemaOpts",
+    "fields",
+    "validates",
+    "validates_schema",
+    "pre_dump",
+    "post_dump",
+    "pre_load",
+    # "post_load",
+    "pprint",
+    "ValidationError",
+    "missing",
+]
+
+from marshmallow import fields
+
+from marshmallow.decorators import (
+    post_dump,
+    # post_load,  # overloaded
+    pre_dump,
+    pre_load,
+    validates,
+    validates_schema,
+)
+from marshmallow.exceptions import ValidationError
+from marshmallow.schema import Schema, SchemaOpts
+from marshmallow.utils import EXCLUDE, INCLUDE, RAISE, missing, pprint
+
+from marshmallow_generic.decorators import post_load
+from marshmallow_generic.schema import GenericSchema

src/marshmallow_generic/schema.py

@@ -54,10 +54,10 @@ class GenericSchema(GenericInsightMixin1[Model], Schema):
         dump_only: Union[Sequence[str], set[str]] = (),
         partial: Union[bool, Sequence[str], set[str]] = False,
         unknown: Optional[str] = None,
-        many: Optional[bool] = None,
+        many: bool = False,  # usage discouraged
     ) -> None:
         """
-        Emits a warning, if the `many` argument is not `None`.
+        Emits a warning, if the `many` argument is not `False`.
 
         Otherwise the same as in [`marshmallow.Schema`][marshmallow.Schema].
 
@@ -72,40 +72,34 @@ class GenericSchema(GenericInsightMixin1[Model], Schema):
                 it is not used. Nested fields can be represented with dot
                 delimiters.
             context:
-                Optional context passed to [`Method`]
-                [marshmallow.fields.Method] and [`Function`]
-                [marshmallow.fields.Function] fields.
+                Optional context passed to
+                [`Method`][marshmallow.fields.Method] and
+                [`Function`][marshmallow.fields.Function] fields.
             load_only:
                 Fields to skip during serialization (write-only fields)
             dump_only:
                 Fields to skip during deserialization (read-only fields)
             partial:
                 Whether to ignore missing fields and not require any fields
-                declared. Propagates down to [`Nested`]
-                [marshmallow.fields.Nested] fields as well. If its value is an
-                iterable, only missing fields listed in that iterable will be
-                ignored. Use dot delimiters to specify nested fields.
+                declared. Propagates down to
+                [`Nested`][marshmallow.fields.Nested] fields as well. If its
+                value is an iterable, only missing fields listed in that
+                iterable will be ignored. Use dot delimiters to specify nested
+                fields.
             unknown:
                 Whether to exclude, include, or raise an error for unknown
                 fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.
             many:
                 !!! warning
-                    Specifying this option schema-wide undermines the type
-                    safety that this class aims to provide and passing any
-                    value other than `None` will trigger a warning. Use the
-                    method-specific `many` parameter, when calling
+                    Changing this option schema-wide undermines the type
+                    safety that this class aims to provide. Passing `True`
+                    will therefore trigger a warning. You should instead use
+                    the method-specific `many` parameter, when calling
                     [`dump`][marshmallow_generic.GenericSchema.dump]/
                     [`dumps`][marshmallow_generic.GenericSchema.dumps] or
                     [`load`][marshmallow_generic.GenericSchema.load]/
-                    [`loads`][marshmallow_generic.GenericSchema.loads] instead.
+                    [`loads`][marshmallow_generic.GenericSchema.loads].
         """
-        if many is not None:
-            warn(
-                "Setting `many` schema-wide breaks type safety. Use the the "
-                "`many` parameter of specific methods (like `load`) instead."
-            )
-        else:
-            many = bool(many)
         super().__init__(
             only=only,
             exclude=exclude,
@@ -117,13 +111,28 @@ class GenericSchema(GenericInsightMixin1[Model], Schema):
             unknown=unknown,
         )
 
+    def __setattr__(self, name: str, value: Any) -> None:
+        """
+        Warns, when trying to set `many` to anything other than `False`.
+
+        Otherwise the same the normal
+        [`object.__setattr__`](https://docs.python.org/3/reference/datamodel.html#object.__setattr__).
+        """
+        if name == "many" and value is not False:
+            warn(
+                "Changing `many` schema-wide breaks type safety. Use the the "
+                "`many` parameter of specific methods (like `load`) instead."
+            )
+        super().__setattr__(name, value)
+
     @post_load
     def instantiate(self, data: dict[str, Any], **_kwargs: Any) -> Model:
         """
         Unpacks `data` into the constructor of the specified **`Model`**.
 
-        Registered as a [`@post_load`]
-        [marshmallow_generic.decorators.post_load] hook for the schema.
+        Registered as a
+        [`@post_load`][marshmallow_generic.decorators.post_load]
+        hook for the schema.
 
         !!! warning
             You should probably not use this method directly. No parsing,
@@ -169,8 +178,9 @@ class GenericSchema(GenericInsightMixin1[Model], Schema):
             """
             Serializes **`Model`** objects to native Python data types.
 
-            Same as [`marshmallow.Schema.dump`]
-            [marshmallow.schema.Schema.dump] at runtime.
+            Same as
+            [`marshmallow.Schema.dump`][marshmallow.schema.Schema.dump]
+            at runtime.
 
             Annotations ensure that type checkers will infer the return type
             correctly based on the `many` argument, and also enforce the `obj`
@@ -254,10 +264,10 @@ class GenericSchema(GenericInsightMixin1[Model], Schema):
             """
             Deserializes data to objects of the specified **`Model`** class.
 
-            Same as [`marshmallow.Schema.load`]
-            [marshmallow.schema.Schema.load] at runtime, but data will always
-            pass through the [`instantiate`]
-            [marshmallow_generic.schema.GenericSchema.instantiate]
+            Same as
+            [`marshmallow.Schema.load`][marshmallow.schema.Schema.load] at
+            runtime, but data will always pass through the
+            [`instantiate`][marshmallow_generic.schema.GenericSchema.instantiate]
             hook after deserialization.
 
             Annotations ensure that type checkers will infer the return type
@@ -271,11 +281,11 @@ class GenericSchema(GenericInsightMixin1[Model], Schema):
                     the value for `self.many` is used.
                 partial:
                     Whether to ignore missing fields and not require any
-                    fields declared. Propagates down to [`Nested`]
-                    [marshmallow.fields.Nested] fields as well. If its value
-                    is an iterable, only missing fields listed in that
-                    iterable will be ignored. Use dot delimiters to specify
-                    nested fields.
+                    fields declared. Propagates down to
+                    [`Nested`][marshmallow.fields.Nested] fields as well. If
+                    its value is an iterable, only missing fields listed in
+                    that iterable will be ignored. Use dot delimiters to
+                    specify nested fields.
                 unknown:
                     Whether to exclude, include, or raise an error for unknown
                     fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.
@@ -323,10 +333,10 @@ class GenericSchema(GenericInsightMixin1[Model], Schema):
             """
             Deserializes data to objects of the specified **`Model`** class.
 
-            Same as [`marshmallow.Schema.loads`]
-            [marshmallow.schema.Schema.loads] at runtime, but data will always
-            pass through the [`instantiate`]
-            [marshmallow_generic.schema.GenericSchema.instantiate]
+            Same as
+            [`marshmallow.Schema.loads`][marshmallow.schema.Schema.loads] at
+            runtime, but data will always pass through the
+            [`instantiate`][marshmallow_generic.schema.GenericSchema.instantiate]
             hook after deserialization.
 
             Annotations ensure that type checkers will infer the return type
@@ -340,11 +350,11 @@ class GenericSchema(GenericInsightMixin1[Model], Schema):
                     the value for `self.many` is used.
                 partial:
                     Whether to ignore missing fields and not require any
-                    fields declared. Propagates down to [`Nested`]
-                    [marshmallow.fields.Nested] fields as well. If its value
-                    is an iterable, only missing fields listed in that
-                    iterable will be ignored. Use dot delimiters to specify
-                    nested fields.
+                    fields declared. Propagates down to
+                    [`Nested`][marshmallow.fields.Nested] fields as well. If
+                    its value is an iterable, only missing fields listed in
+                    that iterable will be ignored. Use dot delimiters to
+                    specify nested fields.
                 unknown:
                     Whether to exclude, include, or raise an error for unknown
                     fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.

tests/test_schema.py

@@ -19,16 +19,20 @@ class GenericSchemaTestCase(TestCase):
             "dump_only": object(),
             "partial": object(),
             "unknown": object(),
-            "many": None,
+            "many": object(),
         }
         schema.GenericSchema[Foo](**kwargs)
-        mock_super_init.assert_called_once_with(**kwargs | {"many": False})
-        mock_super_init.reset_mock()
-        kwargs["many"] = True
-        with self.assertWarns(UserWarning):
-            schema.GenericSchema[Foo](**kwargs)
         mock_super_init.assert_called_once_with(**kwargs)
 
+    def test___setattr__(self) -> None:
+        class Foo:
+            pass
+
+        obj = schema.GenericSchema[Foo]()
+        with self.assertWarns(UserWarning):
+            obj.many = new = MagicMock()
+        self.assertIs(new, obj.many)
+
     @patch.object(_util.GenericInsightMixin, "_get_type_arg")
     def test_instantiate(self, mock__get_type_arg: MagicMock) -> None:
         mock__get_type_arg.return_value = mock_cls = MagicMock()