Data Types

Mapping

Below you can find the mapping of data types between python and xml schema.

Python	XML Type
str	anyAtomicType	anyURI	base	base64Binary	date
	dateTime	dateTimeStamp	dayTimeDuration	yearMonthDuration	derivationControl
	duration	ENTITIES	ENTITY	gDay	gMonth
	gMonthDay	gYear	gYearMonth	hexBinary	ID
	IDREF	IDREFS	lang	language	Name
	NCName	NMTOKEN	NMTOKENS	normalizedString	NOTATION
	simpleDerivationSet	string	time	token
object	anySimpleType	anyType
bool	boolean
int	byte	int	integer	long	negativeInteger
	nonNegativeInteger	nonPositiveInteger	positiveInteger	short	unsignedByte
	unsignedInt	unsignedLong	unsignedShort
decimal.Decimal	decimal	double
float	float
xml.etree.ElementTree	QName
enum.Enum	enumeration

Converters

The build-in converters are used to bind data from and to xml documents. They are also used partially for json data binding when the typing information is lost in the literal representation like enumerations.

The converter will attempt to convert values according to the provided list of possible types but in case of an error it will fall back to str, even if that means violating the field typing definition.

A warning will also be raised in that case.

ConverterWarning: Failed to convert value `a` to one of [<class 'float'>]

You can register your custom type converters if you are working with user defined models with types not supported from the default ones.

@dataclass
class Root:
    updated_at: datetime = field(metadata={"type": "Attribute"})


class DatetimeConverter(Converter):
    def from_string(self, value: str, **kwargs: Any) -> datetime:
        return datetime.fromisoformat(value)

    def to_string(self, value: datetime, **kwargs: Any) -> str:
        return value.isoformat(sep=" ")


converter.register_converter(datetime, DatetimeConverter())
root = XmlParser().from_string('<root updated_at="2011-11-04T00:05:23">', Root)

assert root == Root(updated_at=datetime(2011, 11, 4, 0, 5, 23))