Schema

Definition of the GenericSchema base class.

For details about the inherited methods and attributes, see the official documentation of marshmallow.Schema.

GenericSchema ¶

Bases: GenericInsightMixin1[Model], Schema

Generic schema parameterized by a Model class.

Data will always be deserialized to instances of that Model class.

Note

The Model referred to throughout the documentation is a type variable, not any concrete class. For more information about type variables, see the "Generics" section in PEP 484.

Registers a post_load hook to pass validated data to the constructor of the specified Model.

Requires a specific (non-generic) class to be passed as the Model type argument for deserialization to work properly:

class Foo:  # Model
    ...

class FooSchema(GenericSchema[Foo]):
    ...

init ¶

__init__(
    *,
    only: Union[Sequence[str], set[str], None] = None,
    exclude: Union[Sequence[str], set[str]] = (),
    context: Union[dict[str, Any], None] = None,
    load_only: Union[Sequence[str], set[str]] = (),
    dump_only: Union[Sequence[str], set[str]] = (),
    partial: Union[bool, Sequence[str], set[str]] = False,
    unknown: Optional[str] = None,
    many: bool = False
) -> None

Emits a warning, if the many argument is not False.

Otherwise the same as in marshmallow.Schema.

Parameters:

Name	Type	Description	Default
`only`	`Union[Sequence[str], set[str], None]`	Whitelist of the declared fields to select when instantiating the Schema. If `None`, all fields are used. Nested fields can be represented with dot delimiters.	`None`
`exclude`	`Union[Sequence[str], set[str]]`	Blacklist of the declared fields to exclude when instantiating the Schema. If a field appears in both `only` and `exclude`, it is not used. Nested fields can be represented with dot delimiters.	`()`
`context`	`Union[dict[str, Any], None]`	Optional context passed to `Method` and `Function` fields.	`None`
`load_only`	`Union[Sequence[str], set[str]]`	Fields to skip during serialization (write-only fields)	`()`
`dump_only`	`Union[Sequence[str], set[str]]`	Fields to skip during deserialization (read-only fields)	`()`
`partial`	`Union[bool, Sequence[str], set[str]]`	Whether to ignore missing fields and not require any fields declared. Propagates down to `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.	`False`
`unknown`	`Optional[str]`	Whether to exclude, include, or raise an error for unknown fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`.	`None`
`many`	`bool`	Warning 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`/ `dumps` or `load`/ `loads`.	`False`

setattr ¶

__setattr__(name: str, value: Any) -> None

Warns, when trying to set many to anything other than False.

Otherwise the same the normal object.__setattr__.

dump ¶

dump(
    obj: Union[Model, Iterable[Model]], *, many: Optional[bool] = None
) -> Union[dict[str, Any], list[dict[str, Any]]]

Serializes Model objects to native Python data types.

Same as marshmallow.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 argument to be an a list of Model instances, if many is set to True or a single instance of it, if many is False (or omitted).

Parameters:

Name	Type	Description	Default
`obj`	`Union[Model, Iterable[Model]]`	The object or iterable of objects to serialize	required
`many`	`Optional[bool]`	Whether to serialize `obj` as a collection. If `None`, the value for `self.many` is used.	`None`

Returns:

Type	Description
`dict[str, Any]`	if `many` is set to `False`
`list[dict[str, Any]]`	if `many` is set to `True`

dumps ¶

dumps(
    obj: Union[Model, Iterable[Model]],
    *args: Any,
    many: Optional[bool] = None,
    **kwargs: Any
) -> str

Same as dump, but returns a JSON-encoded string.

instantiate ¶

instantiate(data: dict[str, Any], **_kwargs: Any) -> Model

Unpacks data into the constructor of the specified Model.

Registered as a @post_load hook for the schema.

Warning

You should probably not use this method directly. No parsing, transformation or validation of any kind is done in this method. The data is passed to the Model constructor "as is".

Parameters:

Name	Type	Description	Default
`data`	`dict[str, Any]`	The validated data after deserialization; will be unpacked into the constructor of the specified `Model` class.	required

Returns:

Type	Description
`Model`	Instance of the schema's `Model` initialized with `**data`

load ¶

load(
    data: Union[Mapping[str, Any], Iterable[Mapping[str, Any]]],
    *,
    many: Optional[bool] = None,
    partial: Union[bool, Sequence[str], set[str], None] = None,
    unknown: Optional[str] = None
) -> Union[list[Model], Model]

Deserializes data to objects of the specified Model class.

Same as marshmallow.Schema.load at runtime, but data will always pass through the instantiate hook after deserialization.

Annotations ensure that type checkers will infer the return type correctly based on the Model type argument of the class.

Parameters:

Name	Type	Description	Default
`data`	`Union[Mapping[str, Any], Iterable[Mapping[str, Any]]]`	The data to deserialize	required
`many`	`Optional[bool]`	Whether to deserialize `data` as a collection. If `None`, the value for `self.many` is used.	`None`
`partial`	`Union[bool, Sequence[str], set[str], None]`	Whether to ignore missing fields and not require any fields declared. Propagates down to `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.	`None`
`unknown`	`Optional[str]`	Whether to exclude, include, or raise an error for unknown fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`. If `None`, the value for `self.unknown` is used.	`None`

Returns:

Type	Description
`Model`	if `many` is set to `False`
`list[Model]`	if `many` is set to `True`

loads ¶

loads(
    json_data: str,
    *,
    many: Optional[bool] = None,
    partial: Union[bool, Sequence[str], set[str], None] = None,
    unknown: Optional[str] = None,
    **kwargs: Any
) -> Union[list[Model], Model]

Deserializes data to objects of the specified Model class.

Same as marshmallow.Schema.loads at runtime, but data will always pass through the instantiate hook after deserialization.

Annotations ensure that type checkers will infer the return type correctly based on the Model type argument of the class.

Parameters:

Name	Type	Description	Default
`json_data`	`str`	A JSON string of the data to deserialize	required
`many`	`Optional[bool]`	Whether to deserialize `data` as a collection. If `None`, the value for `self.many` is used.	`None`
`partial`	`Union[bool, Sequence[str], set[str], None]`	Whether to ignore missing fields and not require any fields declared. Propagates down to `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.	`None`
`unknown`	`Optional[str]`	Whether to exclude, include, or raise an error for unknown fields in the data. Use `EXCLUDE`, `INCLUDE` or `RAISE`. If `None`, the value for `self.unknown` is used.	`None`
`**kwargs`	`Any`	Passed to the JSON decoder	`{}`

Returns:

Type	Description
`Model`	if `many` is set to `False`
`list[Model]`	if `many` is set to `True`

Schema

GenericSchema ¶

__init__ ¶

__setattr__ ¶

dump ¶

dumps ¶

instantiate ¶

load ¶

loads ¶

init ¶

setattr ¶