ModelTypeValidator
class ModelTypeValidator(*, load_default=<marshmallow.missing>, missing=<marshmallow.missing>, dump_default=<marshmallow.missing>, default=<marshmallow.missing>, data_key=None, attribute=None, validate=None, required=False, allow_none=None, load_only=False, dump_only=False, error_messages=None, metadata=None, **additional_metadata)
A field able to validate the correct type of a value.
Attributes
context
The context dictionary for the parent Schema.
default
default_error_messages
Default value: {'null': 'Field may not be null.', 'required': 'Missing data for required field.', 'validator_failed': 'Invalid value.'}
Default error messages for various kinds of errors. The keys in this dictionary are passed to Field.make_error. The values are error messages passed to marshmallow.exceptions.ValidationError.
missing
name
Default value: None
parent
Default value: None
root
Default value: None
valid_types
Default value: (<class 'object'>,)
Methods
check_type
ModelTypeValidator.check_type(value, attr, data, **_)
Validates a value against the correct type of the field.
It calls _expected_types to get a list of valid types.
Subclasses can do one of the following:
- Override the
valid_typesproperty with a tuple with the expected types for this field. - Override the
_expected_typesmethod to return a tuple of expected types for the field. - Change
check_typecompletely to customize validation.
This method or the overrides must return the value parameter untouched.
deserialize
ModelTypeValidator.deserialize(value, attr=None, data=None, **kwargs)
Deserialize value.
Parameters
- value (
Any) – The value to deserialize. - attr (
Optional[str]) – The attribute/key in data to deserialize. - data (
Optional[Mapping[str,Any]]) – The raw input data passed to Schema.load. - kwargs – Field-specific keyword arguments.
Raises
ValidationError – If an invalid value is passed or if a required value is missing.
fail
ModelTypeValidator.fail(key, **kwargs)
Helper method that raises a ValidationError with an error message from self.error_messages.
Use make_error <marshmallow.fields.Field.make_error> instead.
get_value
ModelTypeValidator.get_value(obj, attr, accessor=None, default=<marshmallow.missing>)
Return the value for a given key from an object.
Parameters
- obj (object) – The object to get the value from.
- attr (str) – The attribute/key in obj to get the value from.
- accessor (callable) – A callable used to retrieve the value of attr from the object obj. Defaults to marshmallow.utils.get_value.
make_error
ModelTypeValidator.make_error(key, **kwargs)
Helper method to make a ValidationError with an error message from self.error_messages.
Return type
ValidationError
make_error_serialize
ModelTypeValidator.make_error_serialize(key, **kwargs)
Helper method to return a ValidationError from _serialize.
This method wraps the result of make_error(), adding contextual information in order to provide more informative information to users.
Parameters
- key (str) – error key index.
- **kwargs – additional arguments to
make_error().
Returns
an exception with the field name.
Return type
ValidationError
serialize
ModelTypeValidator.serialize(attr, obj, accessor=None, **kwargs)
Pulls the value for the given key from the object, applies the field’s formatting and returns the result.
Parameters
- attr (
str) – The attribute/key to get from the object. - obj (
Any) – The object to access the attribute/key from. - accessor (
Optional[Callable[[Any,str,Any],Any]]) – Function used to access values fromobj. - kwargs – Field-specific keyword arguments.