def get_prep_value(self, value, instance=None):
try:
value = self.prepare(value)
if not value and self.null and self.default is not None:
value = self.default
else:
value = self.to_python(value)
if value not in self.choices:
if not self.null:
raise exceptions.ChoiceError(
"Value \'%s\' does not belong to %s" %
(value, self.choices))
value = None
transform = self.get_transform_method(instance)
value = transform(value)
if not self.validator().validate(value):
raise exceptions.FieldError(self.validator.validation_message)
return value
except exceptions.ChoiceError:
raise
except exceptions.FieldError:
raise
except ValueError:
self.raise_type_error(value)
def __init__(self, **kwargs):
super(Field, self).__init__(kwargs)
self.null = kwargs.pop("null", False)
self.default = kwargs.pop("default", None)
if self.default and not self.null:
raise exceptions.FieldError(
"You cannot provide a default without setting the field as nullable"
)
if 'row_num' in kwargs:
self.position = kwargs.pop('row_num')
else:
self.position = Field.position
Field.position += 1
if 'match' in kwargs:
self.match = kwargs.pop('match')
self.validator = kwargs.pop('validator', AlwaysValidValidator)
if 'multiple' in kwargs:
self.has_multiple = kwargs.pop('multiple')
self.prepare = kwargs.pop('prepare', lambda val: val)
if 'keys' in kwargs and isinstance(self, ComposedKeyField):
self.keys = kwargs.pop('keys')
self.choices = kwargs.pop('choices', AllChoices())
if len(kwargs) > 0:
raise ValueError("Arguments %s unexpected" % kwargs.keys())
