dservercore.schemas

marshmallow schema for (de-) serialization and validation

Classes

`AnnotationSchema`(*[, only, exclude, many, ...])
`ConfigSchema`(*[, only, exclude, many, ...])
`ItemSchema`(*[, only, exclude, many, ...])
`ManifestSchema`(*[, only, exclude, many, ...])
`ReadmeSchema`(*[, only, exclude, many, ...])
`RegisterDatasetSchema`(*[, only, exclude, ...])
`SearchDatasetSchema`(*[, only, exclude, ...])
`SummarySchema`(*[, only, exclude, many, ...])
`TagSchema`(*[, only, exclude, many, context, ...])
`VersionSchema`(*[, only, exclude, many, ...])

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects

Bases: Schema

class Meta

Bases: object

Options object for a Schema.

Example usage:

class Meta:
    fields = ("id", "email", "date_created")
    exclude = ("password", "secret_attribute")

Available options:

fields: Tuple or list of fields to include in the serialized result.
additional: Tuple or list of fields to include in addition to the
explicitly declared fields. additional and fields are mutually-exclusive options.
include: Dictionary of additional fields to include in the schema. It is
usually better to define fields as class variables, but you may need to use this option, e.g., if your fields are Python keywords. May be an OrderedDict.
exclude: Tuple or list of fields to exclude in the serialized result.
Nested fields can be represented with dot delimiters.
dateformat: Default format for Date <fields.Date> fields.
datetimeformat: Default format for DateTime <fields.DateTime> fields.
timeformat: Default format for Time <fields.Time> fields.
render_module: Module to use for loads <Schema.loads> and dumps <Schema.dumps>.
Defaults to json from the standard library.
ordered: If True, output of Schema.dump will be a collections.OrderedDict.
index_errors: If True, errors dictionaries will include the index
of invalid items in a collection.
load_only: Tuple or list of fields to exclude from serialized results.
dump_only: Tuple or list of fields to exclude from deserialization
unknown: Whether to exclude, include, or raise an error for unknown
fields in the data. Use EXCLUDE, INCLUDE or RAISE.
register: Whether to register the Schema with marshmallow’s internal
class registry. Must be True if you intend to refer to this Schema by class name in Nested fields. Only set this to False when memory usage is critical. Defaults to True.

sqla_session = <flask_marshmallow.sqla.DummySession object>

OPTIONS_CLASS: alias of SchemaOpts

TYPE_MAPPING: Dict[type, Type[ma_fields.Field]] = {<class 'bool'>: <class 'marshmallow.fields.Boolean'>, <class 'bytes'>: <class 'marshmallow.fields.String'>, <class 'datetime.date'>: <class 'marshmallow.fields.Date'>, <class 'datetime.datetime'>: <class 'marshmallow.fields.DateTime'>, <class 'datetime.time'>: <class 'marshmallow.fields.Time'>, <class 'datetime.timedelta'>: <class 'marshmallow.fields.TimeDelta'>, <class 'decimal.Decimal'>: <class 'marshmallow.fields.Decimal'>, <class 'float'>: <class 'marshmallow.fields.Float'>, <class 'int'>: <class 'marshmallow.fields.Integer'>, <class 'list'>: <class 'marshmallow.fields.Raw'>, <class 'set'>: <class 'marshmallow.fields.Raw'>, <class 'str'>: <class 'marshmallow.fields.String'>, <class 'tuple'>: <class 'marshmallow.fields.Raw'>, <class 'uuid.UUID'>: <class 'marshmallow.fields.UUID'>}

__init__(*, only: Sequence[str] | AbstractSet[str] | None = None, exclude: Sequence[str] | AbstractSet[str] = (), many: bool = False, context: dict | None = None, load_only: Sequence[str] | AbstractSet[str] = (), dump_only: Sequence[str] | AbstractSet[str] = (), partial: bool | Sequence[str] | AbstractSet[str] | None = None, unknown: str | None = None)

property dict_class: type

dump(obj: Any, *, many: bool | None = None)

Serialize an object to native Python data types according to this Schema’s fields.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

Serialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

Changed in version 3.0.0rc9: Validation no longer occurs upon serialization.

dumps(obj: Any, *args, many: bool | None = None, **kwargs)

Same as dump(), except return a JSON-encoded string.

Parameters:

obj – The object to serialize.
many – Whether to serialize obj as a collection. If None, the value for self.many is used.

Returns:

A json string

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the serialized data rather than a (data, errors) duple. A ValidationError is raised if obj is invalid.

error_messages: Dict[str, str] = {}: Overrides for default schema-level error messages

classmethod from_dict(fields: dict[str, Field | type], *, name: str = 'GeneratedSchema') → type

Generate a Schema class given a dictionary of fields.

from marshmallow import Schema, fields

PersonSchema = Schema.from_dict({"name": fields.Str()})
print(PersonSchema().load({"name": "David"}))  # => {'name': 'David'}

Generated schemas are not added to the class registry and therefore cannot be referred to by name in Nested fields.

Parameters:

fields (dict) – Dictionary mapping field names to field instances.
name (str) – Optional name for the class, which will appear in the repr for the class.

Added in version 3.0.0.

get_attribute(obj: Any, attr: str, default: Any): Defines how to pull values from an object to serialize.

Added in version 2.0.0.

Changed in version 3.0.0a1: Changed position of obj and attr.

handle_error(error: ValidationError, data: Any, *, many: bool, **kwargs)

Custom error handler function for the schema.

Parameters:

error – The ValidationError raised during (de)serialization.
data – The original input data.
many – Value of many on dump or load.
partial – Value of partial on load.

Added in version 2.0.0.

Changed in version 3.0.0rc9: Receives many and partial (on deserialization) as keyword arguments.

Deserialize a data structure to an object defined by this Schema’s fields.

Parameters:

data – The data to deserialize.
many – Whether to deserialize data as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

Same as load(), except it takes a JSON string as input.

Parameters:

json_data – A JSON string of the data to deserialize.
many – Whether to deserialize obj as a collection. If None, the value for self.many is used.
partial – 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.
unknown – 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.

Returns:

Deserialized data

Added in version 1.0.0.

Changed in version 3.0.0b7: This method returns the deserialized data rather than a (data, errors) duple. A ValidationError is raised if invalid data are passed.

on_bind_field(field_name: str, field_obj: Field) → None

Hook to modify a field when it is bound to the Schema.

No-op by default.

opts: SchemaOpts = <marshmallow.schema.SchemaOpts object>

set_class: alias of OrderedSet

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

data – The data to validate.
many – Whether to validate data as a collection. If None, the value for self.many is used.
partial – 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.

Returns:

A dictionary of validation errors.

Added in version 1.1.0.

fields: Dict[str, ma_fields.Field]: Dictionary mapping field_names -> Field objects