Package API

Errors and exceptions

exception XMLSchemaException: The base exception that let you catch all the errors generated by the library.

exception XMLResourceError: Raised when an error is found accessing an XML resource.

exception XMLSchemaNamespaceError: Raised when a wrong runtime condition is found with a namespace.

exception XMLSchemaValidatorError(validator, message, elem=None, source=None, namespaces=None)

Base class for XSD validator errors.

Parameters

validator (XsdValidator or function) – the XSD validator.
message (str or unicode) – the error message.
elem (Element) – the element that contains the error.
source (XMLResource) – the XML resource that contains the error.
namespaces (dict) – is an optional mapping from namespace prefix to URI.

Variables

path – the XPath of the element, calculated when the element is set or the XML resource is set.

exception XMLSchemaNotBuiltError(validator, message)

Raised when there is an improper usage attempt of a not built XSD validator.

Parameters

validator (XsdValidator) – the XSD validator.
message (str or unicode) – the error message.

exception XMLSchemaParseError(validator, message, elem=None)

Raised when an error is found during the building of an XSD validator.

Parameters

validator (XsdValidator or function) – the XSD validator.
message (str or unicode) – the error message.
elem (Element) – the element that contains the error.

exception XMLSchemaModelError(group, message)

Raised when a model error is found during the checking of a model group.

Parameters

group (XsdGroup) – the XSD model group.
message (str or unicode) – the error message.

exception XMLSchemaModelDepthError(group): Raised when recursion depth is exceeded while iterating a model group.

exception XMLSchemaValidationError(validator, obj, reason=None, source=None, namespaces=None)

Raised when the XML data is not validated with the XSD component or schema. It’s used by decoding and encoding methods. Encoding validation errors do not include XML data element and source, so the error is limited to a message containing object representation and a reason.

Parameters

validator (XsdValidator or function) – the XSD validator.
obj (Element or tuple or str or list or int or float or bool) – the not validated XML data.
reason (str or unicode) – the detailed reason of failed validation.
source (XMLResource) – the XML resource that contains the error.
namespaces (dict) – is an optional mapping from namespace prefix to URI.

exception XMLSchemaDecodeError(validator, obj, decoder, reason=None, source=None, namespaces=None)

Raised when an XML data string is not decodable to a Python object.

Parameters

validator (XsdValidator or function) – the XSD validator.
obj (Element or tuple or str or list or int or float or bool) – the not validated XML data.
decoder (type or function) – the XML data decoder.
reason (str or unicode) – the detailed reason of failed validation.
source (XMLResource) – the XML resource that contains the error.
namespaces (dict) – is an optional mapping from namespace prefix to URI.

exception XMLSchemaEncodeError(validator, obj, encoder, reason=None, source=None, namespaces=None)

Raised when an object is not encodable to an XML data string.

Parameters

validator (XsdValidator or function) – the XSD validator.
obj (Element or tuple or str or list or int or float or bool) – the not validated XML data.
encoder (type or function) – the XML encoder.
reason (str or unicode) – the detailed reason of failed validation.
source (XMLResource) – the XML resource that contains the error.
namespaces (dict) – is an optional mapping from namespace prefix to URI.

exception XMLSchemaChildrenValidationError(validator, elem, index, particle, occurs=0, expected=None, source=None, namespaces=None)

Raised when a child element is not validated.

Parameters

validator (XsdValidator or function) – the XSD validator.
elem (Element or ElementData) – the not validated XML element.
index (int) – the child index.
particle (ParticleMixin) – the validator particle that generated the error. Maybe the validator itself.
occurs (int) – the particle occurrences.
expected (str or list or tuple) – the expected element tags/object names.
source (XMLResource) – the XML resource that contains the error.
namespaces (dict) – is an optional mapping from namespace prefix to URI.

exception XMLSchemaIncludeWarning: A schema include fails.

exception XMLSchemaImportWarning: A schema namespace import fails.

exception XMLSchemaTypeTableWarning: Not equivalent type table found in model.

Document level API

validate(xml_document, schema=None, cls=None, path=None, schema_path=None, use_defaults=True, namespaces=None, locations=None, base_url=None, defuse='remote', timeout=300, lazy=False)

Validates an XML document against a schema instance. This function builds an XMLSchema object for validating the XML document. Raises an XMLSchemaValidationError if the XML document is not validated against the schema.

Parameters

xml_document – can be an XMLResource instance, a file-like object a path to a file or an URI of a resource or an Element instance or an ElementTree instance or a string containing the XML data. If the passed argument is not an XMLResource instance a new one is built using this and defuse, timeout and lazy arguments.
schema – can be a schema instance or a file-like object or a file path or a URL of a resource or a string containing the schema.
cls – class to use for building the schema instance (for default XMLSchema10 is used).
path – is an optional XPath expression that matches the elements of the XML data that have to be decoded. If not provided the XML root element is used.
schema_path – an XPath expression to select the XSD element to use for decoding. If not provided the path argument or the source root tag are used.
use_defaults – defines when to use element and attribute defaults for filling missing required values.
namespaces – is an optional mapping from namespace prefix to URI.
locations – additional schema location hints, used if a schema instance has to be built.
base_url – is an optional custom base URL for remapping relative locations, for default uses the directory where the XSD or alternatively the XML document is located.
defuse – optional argument to pass for construct schema and XMLResource instances.
timeout – optional argument to pass for construct schema and XMLResource instances.
lazy – optional argument for construct the XMLResource instance.

is_valid(xml_document, schema=None, cls=None, path=None, schema_path=None, use_defaults=True, namespaces=None, locations=None, base_url=None, defuse='remote', timeout=300, lazy=False): Like validate() except that do not raises an exception but returns True if the XML document is valid, False if it’s invalid.

iter_errors(xml_document, schema=None, cls=None, path=None, schema_path=None, use_defaults=True, namespaces=None, locations=None, base_url=None, defuse='remote', timeout=300, lazy=False): Creates an iterator for the errors generated by the validation of an XML document. Takes the same arguments of the function validate().

to_dict(xml_document, schema=None, cls=None, path=None, process_namespaces=True, locations=None, base_url=None, defuse='remote', timeout=300, lazy=False, **kwargs)

Decodes an XML document to a Python’s nested dictionary. The decoding is based on an XML Schema class instance. For default the document is validated during the decoding phase. Raises an XMLSchemaValidationError if the XML document is not validated against the schema.

Parameters

xml_document – can be an XMLResource instance, a file-like object a path to a file or an URI of a resource or an Element instance or an ElementTree instance or a string containing the XML data. If the passed argument is not an XMLResource instance a new one is built using this and defuse, timeout and lazy arguments.
schema – can be a schema instance or a file-like object or a file path or a URL of a resource or a string containing the schema.
cls – class to use for building the schema instance (for default uses XMLSchema10).
path – is an optional XPath expression that matches the elements of the XML data that have to be decoded. If not provided the XML root element is used.
process_namespaces – indicates whether to use namespace information in the decoding process.
locations – additional schema location hints, in case a schema instance has to be built.
base_url – is an optional custom base URL for remapping relative locations, for default uses the directory where the XSD or alternatively the XML document is located.
defuse – optional argument to pass for construct schema and XMLResource instances.
timeout – optional argument to pass for construct schema and XMLResource instances.
lazy – optional argument for construct the XMLResource instance.
kwargs – other optional arguments of XMLSchema.iter_decode() as keyword arguments.

Returns

an object containing the decoded data. If validation='lax' keyword argument is provided the validation errors are collected and returned coupled in a tuple with the decoded data.

Raises

XMLSchemaValidationError if the object is not decodable by the XSD component, or also if it’s invalid when validation='strict' is provided.

to_json(xml_document, fp=None, schema=None, cls=None, path=None, converter=None, process_namespaces=True, locations=None, base_url=None, defuse='remote', timeout=300, lazy=False, json_options=None, **kwargs)

Serialize an XML document to JSON. For default the XML data is validated during the decoding phase. Raises an XMLSchemaValidationError if the XML document is not validated against the schema.

Parameters

xml_document – can be an XMLResource instance, a file-like object a path to a file or an URI of a resource or an Element instance or an ElementTree instance or a string containing the XML data. If the passed argument is not an XMLResource instance a new one is built using this and defuse, timeout and lazy arguments.
fp – can be a write() supporting file-like object.
schema – can be a schema instance or a file-like object or a file path or an URL of a resource or a string containing the schema.
cls – schema class to use for building the instance (for default uses XMLSchema10).
path – is an optional XPath expression that matches the elements of the XML data that have to be decoded. If not provided the XML root element is used.
converter – an XMLSchemaConverter subclass or instance to use for the decoding.
process_namespaces – indicates whether to use namespace information in the decoding process.
locations – additional schema location hints, in case the schema instance has to be built.
base_url – is an optional custom base URL for remapping relative locations, for default uses the directory where the XSD or alternatively the XML document is located.
defuse – optional argument to pass for construct schema and XMLResource instances.
timeout – optional argument to pass for construct schema and XMLResource instances.
lazy – optional argument for construct the XMLResource instance.
json_options – a dictionary with options for the JSON serializer.
kwargs – optional arguments of XMLSchema.iter_decode() as keyword arguments to variate the decoding process.

Returns

a string containing the JSON data if fp is None, otherwise doesn’t return anything. If validation='lax' keyword argument is provided the validation errors are collected and returned, eventually coupled in a tuple with the JSON data.

Raises

XMLSchemaValidationError if the object is not decodable by the XSD component, or also if it’s invalid when validation='strict' is provided.

from_json(source, schema, path=None, converter=None, json_options=None, **kwargs)

Deserialize JSON data to an XML Element.

Parameters

source – can be a string or a read() supporting file-like object containing the JSON document.
schema – an XMLSchema10 or an XMLSchema11 instance.
path – is an optional XPath expression for selecting the element of the schema that matches the data that has to be encoded. For default the first global element of the schema is used.
converter – an XMLSchemaConverter subclass or instance to use for the encoding.
json_options – a dictionary with options for the JSON deserializer.
kwargs – Keyword arguments containing options for converter and encoding.

Returns

An element tree’s Element instance. If validation='lax' keyword argument is provided the validation errors are collected and returned coupled in a tuple with the Element instance.

Raises

XMLSchemaValidationError if the object is not encodable by the schema, or also if it’s invalid when validation='strict' is provided.

Schema level API

class xmlschema.XMLSchema10

class xmlschema.XMLSchema11: The classes for XSD v1.0 and v1.1 schema instances. They are both generated by the meta-class XMLSchemaMeta and take the same API of XMLSchemaBase.

XMLSchema: alias of XMLSchema10

class XMLSchemaBase(source, namespace=None, validation='strict', global_maps=None, converter=None, locations=None, base_url=None, allow='all', defuse='remote', timeout=300, build=True, use_meta=True, use_fallback=True, loglevel=None)

Base class for an XML Schema instance.

Parameters

source (Element or ElementTree or str or file-like object) – an URI that reference to a resource or a file path or a file-like object or a string containing the schema or an Element or an ElementTree document.
namespace (str or None) – is an optional argument that contains the URI of the namespace. When specified it must be equal to the targetNamespace declared in the schema.
validation (str) – the XSD validation mode to use for build the schema, that can be ‘strict’ (default), ‘lax’ or ‘skip’.
global_maps (XsdGlobals or None) – is an optional argument containing an XsdGlobals instance, a mediator object for sharing declaration data between dependents schema instances.
converter (XMLSchemaConverter or None) – is an optional argument that can be an XMLSchemaConverter subclass or instance, used for defining the default XML data converter for XML Schema instance.
locations (dict or list or tuple or None) – schema extra location hints, that can include custom resource locations (eg. local XSD file instead of remote resource) or additional namespaces to import after processing schema’s import statements. Can be a dictionary or a sequence of couples (namespace URI, resource URL). Extra locations passed using a tuple container are not normalized.
base_url (str or None) – is an optional base URL, used for the normalization of relative paths when the URL of the schema resource can’t be obtained from the source argument.
allow (str) – defines the security mode for accessing resource locations. Can be ‘all’, ‘remote’, ‘local’ or ‘sandbox’. Default is ‘all’ that means all types of URLs are allowed. With ‘remote’ only remote resource URLs are allowed. With ‘local’ only file paths and URLs are allowed. With ‘sandbox’ only file paths and URLs that are under the directory path identified by source or by the base_url argument are allowed.
defuse (str) – defines when to defuse XML data using a SafeXMLParser. Can be ‘always’, ‘remote’ or ‘never’. For default defuses only remote XML data.
timeout (int) – the timeout in seconds for fetching resources. Default is 300.
build (bool) – defines whether build the schema maps. Default is True.
use_meta (bool) – if True the schema processor uses the validator meta-schema, otherwise a new meta-schema is added at the end. In the latter case the meta-schema is rebuilt if any base namespace has been overridden by an import. Ignored if the argument global_maps is provided.
use_fallback (bool) – if True the schema processor uses the validator fallback location hints to load well-known namespaces (eg. xhtml).
loglevel (int) – for setting a different logging level for schema initialization and building. For default is WARNING (30). For INFO level set it with 20, for DEBUG level with 10. The default loglevel is restored after schema building, when exiting the initialization method.

Variables

XSD_VERSION (str) – store the XSD version (1.0 or 1.1).
BUILDERS (namedtuple) – a namedtuple with attributes related to schema components classes. Used for build local components within parsing methods.
BUILDERS_MAP (dict) – a dictionary that maps from tag to class for XSD global components. Used for build global components within lookup functions.
BASE_SCHEMAS (dict) – a dictionary from namespace to schema resource for meta-schema bases.
fallback_locations (dict) – fallback schema location hints for other standard namespaces.
meta_schema (XMLSchema) – the XSD meta-schema instance.
attribute_form_default (str) – the schema’s attributeFormDefault attribute. Default is ‘unqualified’.
element_form_default (str) – the schema’s elementFormDefault attribute. Default is ‘unqualified’.
block_default (str) – the schema’s blockDefault attribute. Default is ‘’.
final_default (str) – the schema’s finalDefault attribute. Default is ‘’.
default_attributes (XsdAttributeGroup) – the XSD 1.1 schema’s defaultAttributes attribute. Default is None.
xpath_tokens (dict) – symbol table for schema bound XPath 2.0 parsers. Initially set to None it’s redefined at instance level with a dictionary at first use of the XPath selector. The parser symbol table is extended with schema types constructors.
target_namespace (str) – is the targetNamespace of the schema, the namespace to which belong the declarations/definitions of the schema. If it’s empty no namespace is associated with the schema. In this case the schema declarations can be reused from other namespaces as chameleon definitions.
validation (str) – validation mode, can be ‘strict’, ‘lax’ or ‘skip’.
maps (XsdGlobals) – XSD global declarations/definitions maps. This is an instance of XsdGlobal, that store the global_maps argument or a new object when this argument is not provided.
converter (XMLSchemaConverter) – the default converter used for XML data decoding/encoding.
locations (NamespaceResourcesMap) – schema location hints.
namespaces (dict) – a dictionary that maps from the prefixes used by the schema into namespace URI.
imports (dict) – a dictionary of namespace imports of the schema, that maps namespace URI to imported schema object, or None in case of unsuccessful import.
includes – a dictionary of included schemas, that maps a schema location to an included schema. It also comprehend schemas included by “xs:redefine” or “xs:override” statements.
warnings (list) – warning messages about failure of import and include elements.
notations (NamespaceView) – xsd:notation declarations.
types (NamespaceView) – xsd:simpleType and xsd:complexType global declarations.
attributes (NamespaceView) – xsd:attribute global declarations.
attribute_groups (NamespaceView) – xsd:attributeGroup definitions.
groups (NamespaceView) – xsd:group global definitions.
elements (NamespaceView) – xsd:element global declarations.

root: Root element of the schema.

get_text(): Returns the source text of the XSD schema.

url: Schema resource URL, is None if the schema is built from a string.

tag: Schema root tag. For compatibility with the ElementTree API.

id: The schema’s id attribute, defaults to None.

version: The schema’s version attribute, defaults to None.

schema_location: A list of location hints extracted from the xsi:schemaLocation attribute of the schema.

no_namespace_schema_location: A location hint extracted from the xsi:noNamespaceSchemaLocation attribute of the schema.

target_prefix: The prefix associated to the targetNamespace.

default_namespace: The namespace associated to the empty prefix ‘’.

base_url: The base URL of the source of the schema.

root_elements: The list of global elements that are not used by reference in any model of the schema. This is implemented as lazy property because it’s computationally expensive to build when the schema model is complex.

simple_types: Returns a list containing the global simple types.

complex_types: Returns a list containing the global complex types.

classmethod builtin_types(): Returns the XSD built-in types of the meta-schema.

classmethod create_meta_schema(source=None, base_schemas=None, global_maps=None)

Creates a new meta-schema instance.

Parameters

source – an optional argument referencing to or containing the XSD meta-schema resource. Required if the schema class doesn’t already have a meta-schema.
base_schemas – an optional dictionary that contains namespace URIs and schema locations. If provided it’s used as substitute for class ‘s BASE_SCHEMAS. Also a sequence of (namespace, location) items can be provided if there are more schema documents for one or more namespaces.
global_maps – is an optional argument containing an XsdGlobals instance for the new meta schema. If not provided a new map is created.

create_any_content_group(parent, any_element=None)

Creates a model group related to schema instance that accepts any content.

Parameters

parent – the parent component to set for the any content group.
any_element – an optional any element to use for the content group. When provided it’s copied, linked to the group and the minOccurs/maxOccurs are set to 0 and ‘unbounded’.

create_any_attribute_group(parent)

Creates an attribute group related to schema instance that accepts any attribute.

Parameters: parent – the parent component to set for the any attribute group.

create_any_type(): Creates an xs:anyType equivalent type related with the wildcards connected to global maps of the schema instance in order to do a correct namespace lookup during wildcards validation.

get_locations(namespace): Get a list of location hints for a namespace.

include_schema(location, base_url=None)

Includes a schema for the same namespace, from a specific URL.

Parameters

location – is the URL of the schema.
base_url – is an optional base URL for fetching the schema resource.

Returns

the included XMLSchema instance.

import_schema(namespace, location, base_url=None, force=False, build=False)

Imports a schema for an external namespace, from a specific URL.

Parameters

namespace – is the URI of the external namespace.
location – is the URL of the schema.
base_url – is an optional base URL for fetching the schema resource.
force – if set to True imports the schema also if the namespace is already imported.
build – defines when to build the imported schema, the default is to not build.

Returns

the imported XMLSchema instance.

export(target, only_relative=True)

Exports a schema instance. The schema instance is exported to a directory with also the hierarchy of imported/included schemas.

Parameters

target – a path to a local empty directory.
only_relative – for default only loaded schemas referred by a relative location are saved. If False is provided all the loaded schemas are saved.

resolve_qname(qname, namespace_imported=True)

QName resolution for a schema instance.

Parameters

qname – a string in xs:QName format.
namespace_imported – if this argument is True raises an XMLSchemaNamespaceError if the namespace of the QName is not the targetNamespace and the namespace is not imported by the schema.

Returns

an expanded QName in the format “{namespace-URI}*local-name*”.

Raises

XMLSchemaValueError for an invalid xs:QName is found, XMLSchemaKeyError if the namespace prefix is not declared in the schema instance.

iter_globals(schema=None)

Creates an iterator for XSD global definitions/declarations related to schema namespace.

Parameters: schema – Optional argument for filtering only globals related to a schema instance.

iter_components(xsd_classes=None)

Iterates yielding the schema and its components. For default includes all the relevant components of the schema, excluding only facets and empty attribute groups. The first returned component is the schema itself.

Parameters: xsd_classes – provide a class or a tuple of classes to restrict the range of component types yielded.

classmethod check_schema(schema, namespaces=None)

Validates the given schema against the XSD meta-schema (meta_schema).

Parameters

schema – the schema instance that has to be validated.
namespaces – is an optional mapping from namespace prefix to URI.

Raises

XMLSchemaValidationError if the schema is invalid.

build(): Builds the schema’s XSD global maps.

clear(): Clears the schema’s XSD global maps.

built

validation_attempted

validity: Property that returns the XSD validator’s validity. It can be ‘valid’, ‘invalid’ or ‘notKnown’.

https://www.w3.org/TR/xmlschema-1/#e-validity

https://www.w3.org/TR/2012/REC-xmlschema11-1-20120405/#e-validity

all_errors: A list with all the building errors of the XSD validator and its components.

get_converter(converter=None, **kwargs)

Returns a new converter instance.

Parameters

converter – can be a converter class or instance. If it’s an instance the new instance is copied from it and configured with the provided arguments.
kwargs – optional arguments for initialize the converter instance.

Returns

a converter instance.

validate(source, path=None, schema_path=None, use_defaults=True, namespaces=None)

Validates an XML data against the XSD schema/component instance.

Raises: XMLSchemaValidationError if XML data instance is not a valid.

is_valid(source, path=None, schema_path=None, use_defaults=True, namespaces=None): Like validate() except that do not raises an exception but returns True if the XML data is valid, False if it’s invalid.

iter_errors(source, path=None, schema_path=None, use_defaults=True, namespaces=None)

Creates an iterator for the errors generated by the validation of an XML data against the XSD schema/component instance.

Parameters

source – the source of XML data. Can be an XMLResource instance, a path to a file or an URI of a resource or an opened file-like object or an Element instance or an ElementTree instance or a string containing the XML data.
path – is an optional XPath expression that matches the elements of the XML data that have to be decoded. If not provided the XML root element is selected.
schema_path – an alternative XPath expression to select the XSD element to use for decoding. Useful if the root of the XML data doesn’t match an XSD global element of the schema.
use_defaults – Use schema’s default values for filling missing data.
namespaces – is an optional mapping from namespace prefix to URI.

decode(source, path=None, schema_path=None, validation='strict', *args, **kwargs): Decodes XML data. Takes the same arguments of the method XMLSchema.iter_decode().

iter_decode(source, path=None, schema_path=None, validation='lax', process_namespaces=True, namespaces=None, use_defaults=True, decimal_type=None, datetime_types=False, binary_types=False, converter=None, filler=None, fill_missing=False, keep_unknown=False, max_depth=None, depth_filler=None, **kwargs)

Creates an iterator for decoding an XML source to a data structure.

Parameters

source – the source of XML data. Can be an XMLResource instance, a path to a file or an URI of a resource or an opened file-like object or an Element instance or an ElementTree instance or a string containing the XML data.
path – is an optional XPath expression that matches the elements of the XML data that have to be decoded. If not provided the XML root element is selected.
schema_path – an alternative XPath expression to select the XSD element to use for decoding. Useful if the root of the XML data doesn’t match an XSD global element of the schema.
validation – defines the XSD validation mode to use for decode, can be ‘strict’, ‘lax’ or ‘skip’.
process_namespaces – whether to use namespace information in the

decoding process, using the map provided with the argument namespaces and the map extracted from the XML document. :param namespaces: is an optional mapping from namespace prefix to URI. :param use_defaults: whether to use default values for filling missing data. :param decimal_type: conversion type for Decimal objects (generated by xs:decimal built-in and derived types), useful if you want to generate a JSON-compatible data structure. :param datetime_types: if set to True the datetime and duration XSD types are decoded, otherwise their origin XML string is returned. :param binary_types: if set to True xs:hexBinary and xs:base64Binary types are decoded, otherwise their origin XML string is returned. :param converter: an XMLSchemaConverter subclass or instance to use for decoding. :param filler: an optional callback function to fill undecodable data with a typed value. The callback function must accept one positional argument, that can be an XSD Element or an attribute declaration. If not provided undecodable data is replaced by None. :param fill_missing: if set to True the decoder fills also missing attributes. The filling value is None or a typed value if the filler callback is provided. :param keep_unknown: if set to True unknown tags are kept and are decoded with xs:anyType. For default unknown tags not decoded by a wildcard are discarded. :param max_depth: maximum level of decoding, for default there is no limit. :param depth_filler: an optional callback function to replace data over the max_depth level. The callback function must accept one positional argument, that can be an XSD Element. If not provided deeper data are replaced with None values. :param kwargs: keyword arguments with other options for converter and decoder. :return: yields a decoded data object, eventually preceded by a sequence of validation or decoding errors.

encode(obj, path=None, validation='strict', *args, **kwargs)

Encodes to XML data. Takes the same arguments of the method XMLSchema.iter_encode().

Returns: An ElementTree’s Element or a list containing a sequence of ElementTree’s elements if the argument path matches multiple XML data chunks. If validation argument is ‘lax’ a 2-items tuple is returned, where the first item is the encoded object and the second item is a list containing the errors.

iter_encode(obj, path=None, validation='lax', namespaces=None, use_defaults=True, converter=None, unordered=False, **kwargs)

Creates an iterator for encoding a data structure to an ElementTree’s Element.

Parameters

obj – the data that has to be encoded to XML data.
path – is an optional XPath expression for selecting the element of the schema that matches the data that has to be encoded. For default the first global element of the schema is used.
validation – the XSD validation mode. Can be ‘strict’, ‘lax’ or ‘skip’.
namespaces – is an optional mapping from namespace prefix to URI.
use_defaults – whether to use default values for filling missing data.
converter – an XMLSchemaConverter subclass or instance to use for the encoding.
unordered – a flag for explicitly activating unordered encoding mode for content model data. This mode uses content models for a reordered-by-model iteration of the child elements.
kwargs – Keyword arguments containing options for converter and encoding.

Returns

yields an Element instance/s or validation/encoding errors.

Global maps API

class XsdGlobals(validator, validation='strict')

Mediator class for related XML schema instances. It stores the global declarations defined in the registered schemas. Register a schema to add its declarations to the global maps.

Parameters

validator – the origin schema class/instance used for creating the global maps.
validation – the XSD validation mode to use, can be ‘strict’, ‘lax’ or ‘skip’.

build(): Build the maps of XSD global definitions/declarations. The global maps are updated adding and building the globals of not built registered schemas.

check(schemas=None, validation='strict')

Checks the global maps. For default checks all schemas and raises an exception at first error.

Parameters

schemas – optional argument with the set of the schemas to check.
validation – overrides the default validation mode of the validator.

Raise

XMLSchemaParseError

clear(remove_schemas=False, only_unbuilt=False)

Clears the instance maps and schemas.

Parameters

remove_schemas – removes also the schema instances.
only_unbuilt – removes only not built objects/schemas.

copy(validator=None, validation=None): Makes a copy of the object.

iter_globals(): Creates an iterator for XSD global definitions/declarations.

iter_schemas(): Creates an iterator for the schemas registered in the instance.

lookup(tag, qname)

General lookup method for XSD global components.

Parameters

tag – the expanded QName of the XSD the global declaration/definition (eg. ‘{http://www.w3.org/2001/XMLSchema}element’), that is used to select the global map for lookup.
qname – the expanded QName of the component to be looked-up.

Returns

an XSD global component.

Raises

an XMLSchemaValueError if the tag argument is not appropriate for a global component, an XMLSchemaKeyError if the qname argument is not found in the global map.

register(schema): Registers an XMLSchema instance.

property unbuilt: Property that returns a list with unbuilt components.

Converters API

The base class XMLSchemaConverter is used for defining generic converters. The subclasses implement some of the most used conventions for converting XML to JSON data.

class ElementData(tag, text, content, attributes): Namedtuple for Element data interchange between decoders and converters. The field tag is a string containing the Element’s tag, text can be None or a string representing the Element’s text, content can be None, a list containing the Element’s children or a dictionary containing element name to list of element contents for the Element’s children (used for unordered input data), attributes can be None or a dictionary containing the Element’s attributes.

class XMLSchemaConverter(namespaces=None, dict_class=None, list_class=None, etree_element_class=None, text_key='$', attr_prefix='@', cdata_prefix=None, indent=4, strip_namespaces=False, preserve_root=False, force_dict=False, force_list=False, **kwargs)

Generic XML Schema based converter class. A converter is used to compose decoded XML data for an Element into a data structure and to build an Element from encoded data structure. There are two methods for interfacing the converter with the decoding/encoding process. The method element_decode accepts an ElementData tuple, containing the element parts, and returns a data structure. The method element_encode accepts a data structure and returns an ElementData tuple. For default character data parts are ignored. Prefixes and text key can be changed also using alphanumeric values but ambiguities with schema elements could affect XML data re-encoding.

Parameters

namespaces – map from namespace prefixes to URI.
dict_class – dictionary class to use for decoded data. Default is dict.
list_class – list class to use for decoded data. Default is list.
etree_element_class – the class that has to be used to create new XML elements, if not provided uses the ElementTree’s Element class.
text_key – is the key to apply to element’s decoded text data.
attr_prefix – controls the mapping of XML attributes, to the same name or with a prefix. If None the converter ignores attributes.
cdata_prefix – is used for including and prefixing the character data parts of a mixed content, that are labeled with an integer instead of a string. Character data parts are ignored if this argument is None.
indent – number of spaces for XML indentation (default is 4).
strip_namespaces – if set to True removes namespace declarations from data and namespace information from names, during decoding or encoding. Defaults to False.
preserve_root – if set to True the root element is preserved, wrapped into a single-item dictionary. Applicable only to default converter and to ParkerConverter.
force_dict – if set to True complex elements with simple content are decoded with a dictionary also if there are no decoded attributes. Applicable to default converter only. Defaults to False.
force_list – if set to True child elements are decoded within a list in any case. Applicable to default converter only. Defaults to False.

Variables

dict – dictionary class to use for decoded data.
list – list class to use for decoded data.
etree_element_class – Element class to use
text_key – key for decoded Element text
attr_prefix – prefix for attribute names
cdata_prefix – prefix for character data parts
indent – indentation to use for rebuilding XML trees
preserve_root – preserve the root element on decoding
force_dict – force dictionary for complex elements with simple content
force_list – force list for child elements

lossy: The converter ignores some kind of XML data during decoding/encoding.

losslessly: The XML data is decoded without loss of quality, neither on data nor on data model shape. Only losslessly converters can be always used to encode to an XML data that is strictly conformant to the schema.

copy(**kwargs)

map_attributes(attributes)

Creates an iterator for converting decoded attributes to a data structure with appropriate prefixes. If the instance has a not-empty map of namespaces registers the mapped URIs and prefixes.

Parameters: attributes – A sequence or an iterator of couples with the name of the attribute and the decoded value. Default is None (for simpleType elements, that don’t have attributes).

map_content(content)

A generator function for converting decoded content to a data structure. If the instance has a not-empty map of namespaces registers the mapped URIs and prefixes.

Parameters: content – A sequence or an iterator of tuples with the name of the element, the decoded value and the XsdElement instance associated.

etree_element(tag, text=None, children=None, attrib=None, level=0)

Builds an ElementTree’s Element using arguments and the element class and the indent spacing stored in the converter instance.

Parameters

tag – the Element tag string.
text – the Element text.
children – the list of Element children/subelements.
attrib – a dictionary with Element attributes.
level – the level related to the encoding process (0 means the root).

Returns

an instance of the Element class setted for the converter instance.

element_decode(data, xsd_element, xsd_type=None, level=0)

Converts a decoded element data to a data structure.

Parameters

data – ElementData instance decoded from an Element node.
xsd_element – the XsdElement associated to decoded the data.
xsd_type – optional XsdType for supporting dynamic type through xsi:type or xs:alternative.
level – the level related to the decoding process (0 means the root).

Returns

a data structure containing the decoded data.

element_encode(obj, xsd_element, level=0)

Extracts XML decoded data from a data structure for encoding into an ElementTree.

Parameters

obj – the decoded object.
xsd_element – the XsdElement associated to the decoded data structure.
level – the level related to the encoding process (0 means the root).

Returns

an ElementData instance.

map_qname(qname)

Converts an extended QName to the prefixed format. Only registered namespaces are mapped.

Parameters: qname – a QName in extended format or a local name.
Returns: a QName in prefixed format or a local name.

unmap_qname(qname, name_table=None)

Converts a QName in prefixed format or a local name to the extended QName format. Local names are converted only if a default namespace is included in the instance. If a name_table is provided a local name is mapped to the default namespace only if not found in the name table.

Parameters

qname – a QName in prefixed format or a local name
name_table – an optional lookup table for checking local names.

Returns

a QName in extended format or a local name.

class UnorderedConverter(namespaces=None, dict_class=None, list_class=None, etree_element_class=None, text_key='$', attr_prefix='@', cdata_prefix=None, indent=4, strip_namespaces=False, preserve_root=False, force_dict=False, force_list=False, **kwargs): Same as XMLSchemaConverter but element_encode() returns a dictionary for the content of the element, that can be used directly for unordered encoding mode. In this mode the order of the elements in the encoded output is based on the model visitor pattern rather than the order in which the elements were added to the input dictionary. As the order of the input dictionary is not preserved, character data between sibling elements are interleaved between tags.

class ParkerConverter(namespaces=None, dict_class=None, list_class=None, preserve_root=False, **kwargs)

XML Schema based converter class for Parker convention.

ref: http://wiki.open311.org/JSON_and_XML_Conversion/#the-parker-convention ref: https://developer.mozilla.org/en-US/docs/Archive/JXON#The_Parker_Convention

Parameters

namespaces – Map from namespace prefixes to URI.
dict_class – Dictionary class to use for decoded data. Default is dict for Python 3.6+ or OrderedDict for previous versions.
list_class – List class to use for decoded data. Default is list.
preserve_root – If True the root element will be preserved. For default the Parker convention remove the document root element, returning only the value.

class BadgerFishConverter(namespaces=None, dict_class=None, list_class=None, **kwargs)

XML Schema based converter class for Badgerfish convention.

ref: http://www.sklar.com/badgerfish/ ref: http://badgerfish.ning.com/

Parameters

namespaces – Map from namespace prefixes to URI.
dict_class – Dictionary class to use for decoded data. Default is dict for Python 3.6+ or OrderedDict for previous versions.
list_class – List class to use for decoded data. Default is list.

class AbderaConverter(namespaces=None, dict_class=None, list_class=None, **kwargs)

XML Schema based converter class for Abdera convention.

ref: http://wiki.open311.org/JSON_and_XML_Conversion/#the-abdera-convention ref: https://cwiki.apache.org/confluence/display/ABDERA/JSON+Serialization

Parameters

namespaces – Map from namespace prefixes to URI.
dict_class – Dictionary class to use for decoded data. Default is dict for Python 3.6+ or OrderedDict for previous versions.
list_class – List class to use for decoded data. Default is list.

class JsonMLConverter(namespaces=None, dict_class=None, list_class=None, **kwargs)

XML Schema based converter class for JsonML (JSON Mark-up Language) convention.

ref: http://www.jsonml.org/ ref: https://www.ibm.com/developerworks/library/x-jsonml/

Parameters

namespaces – Map from namespace prefixes to URI.
dict_class – Dictionary class to use for decoded data. Default is dict for Python 3.6+ or OrderedDict for previous versions.
list_class – List class to use for decoded data. Default is list.

class ColumnarConverter(namespaces=None, dict_class=None, list_class=None, attr_prefix='', **kwargs)

XML Schema based converter class for columnar formats.

Parameters

namespaces – map from namespace prefixes to URI.
dict_class – dictionary class to use for decoded data. Default is dict.
list_class – list class to use for decoded data. Default is list.
attr_prefix – used as separator string for renaming the decoded attributes. Can be the empty string (the default) or a single/double underscore.

XML resources API

fetch_resource(location, base_url=None, timeout=30)

Fetch a resource by trying to access it. If the resource is accessible returns its URL, otherwise raises an XMLResourceError.

Parameters

location – an URL or a file path.
base_url – reference base URL for normalizing local and relative URLs.
timeout – the timeout in seconds for the connection attempt in case of remote data.

Returns

a normalized URL.

fetch_schema(source, locations=None, base_url=None, allow='all', defuse='remote', timeout=30): Like fetch_schema_locations() but returns only a reachable location hint for a schema related to the source’s namespace.

fetch_schema_locations(source, locations=None, base_url=None, allow='all', defuse='remote', timeout=30)

Fetches schema location hints from an XML data source and a list of location hints. If an accessible schema location is not found raises a ValueError.

Parameters

source – can be an XMLResource instance, a file-like object a path to a file or an URI of a resource or an Element instance or an ElementTree instance or a string containing the XML data. If the passed argument is not an XMLResource instance a new one is built using this and defuse, timeout and lazy arguments.
locations – a dictionary or dictionary items with additional schema location hints.
base_url – the same argument of the XMLResource.
allow – the same argument of the XMLResource.
defuse – the same argument of the XMLResource.
timeout – the same argument of the XMLResource but with a reduced default.

Returns

A 2-tuple with the URL referring to the first reachable schema resource and a list of dictionary items with normalized location hints.

normalize_url(url, base_url=None, keep_relative=False)

Returns a normalized URL doing a join with a base URL. URL scheme defaults to ‘file’ and backslashes are replaced with slashes. For file paths the os.path.join is used instead of urljoin.

Parameters

url – a relative or absolute URL.
base_url – the reference base URL for construct the normalized URL from the argument. For compatibility between “os.path.join” and “urljoin” a trailing ‘/’ is added to not empty paths.
keep_relative – if set to True keeps relative file paths, which would not strictly conformant to URL format specification.

Returns

A normalized URL.

class XMLResource(source, base_url=None, allow='all', defuse='remote', timeout=300, lazy=False)

XML resource reader based on ElementTree and urllib.

Parameters

source – a string containing the XML document or file path or an URL or a file like object or an ElementTree or an Element.
base_url – is an optional base URL, used for the normalization of relative paths when the URL of the resource can’t be obtained from the source argument. For security access to a local file resource is always denied if the base_url is a remote URL.
allow – defines the security mode for accessing resource locations. Can be ‘all’, ‘remote’, ‘local’ or ‘sandbox’. Default is ‘all’ that means all types of URLs are allowed. With ‘remote’ only remote resource URLs are allowed. With ‘local’ only file paths and URLs are allowed. With ‘sandbox’ only file paths and URLs that are under the directory path identified by the base_url argument are allowed.
defuse – defines when to defuse XML data using a SafeXMLParser. Can be ‘always’, ‘remote’ or ‘never’. For default defuses only remote XML data.
timeout – the timeout in seconds for the connection attempt in case of remote data.
lazy – if a value False or 0 is provided the XML data is fully loaded into and processed from memory. For default only the root element of the source is loaded, except in case the source argument is an Element or an ElementTree instance. A positive integer also defines the depth at which the lazy resource can be better iterated (True means 1).

root: The XML tree root Element.

text: The XML text source, None if it’s not available.

url: The source URL, None if the instance is created from an Element tree or from a string.

base_url: The effective base URL used for completing relative locations.

namespace: The namespace of the XML resource.

parse(source, lazy=False)

tostring(indent='', max_lines=None, spaces_for_tab=4, xml_declaration=False): Generates a string representation of the XML resource.

open(): Returns a opened resource reader object for the instance URL. If the source attribute is a seekable file-like object rewind the source and return it.

load(): Loads the XML text from the data source. If the data source is an Element the source XML text can’t be retrieved.

is_lazy(): Returns True if the XML resource is lazy.

lazy_depth: The optimal depth for validate this resource. Is a positive integer for lazy resources and 0 for fully loaded XML trees.

is_remote(): Returns True if the resource is related with remote XML data.

is_local(): Returns True if the resource is related with local XML data.

is_loaded(): Returns True if the XML text of the data source is loaded.

iter(tag=None, nsmap=None): XML resource tree iterator. The iteration of a lazy resource is in reverse order (top level element is the last). If tag is not None or ‘*’, only elements whose tag equals tag are returned from the iterator. Provide a nsmap list for tracking the namespaces of yielded elements. If nsmap is a dictionary the tracking of namespaces is cumulative on the whole tree, renaming prefixes in case of conflicts.

iter_depth(mode=1, nsmap=None, ancestors=None)

Iterates XML subtrees. For fully loaded resources yields the root element. On lazy resources the argument mode can change the sequence and the completeness of yielded elements. There are four possible modes, that generate different sequences of elements:

Only the elements at depth_level level of the tree

Only a root element pruned at depth_level

The elements at depth_level and then a pruned root

An incomplete root at start, the elements at depth_level and a pruned root

Parameters

mode – an integer in range [1..4] that defines the iteration mode.
nsmap – provide a list/dict for tracking the namespaces of yielded elements. If a list is passed the tracking is done at element level, otherwise the tracking is on the whole tree, renaming prefixes in case of conflicts.
ancestors – provide a list for tracking the ancestors of yielded elements.

iterfind(path, namespaces=None, nsmap=None, ancestors=None)

Apply XPath selection to XML resource that yields full subtrees.

Parameters

path – an XPath expression to select element nodes.
namespaces – an optional mapping from namespace prefixes to URIs used for parsing the XPath expression.
nsmap – provide a list/dict for tracking the namespaces of yielded elements. If a list is passed the tracking is done at element level, otherwise the tracking is on the whole tree, renaming prefixes in case of conflicts.
ancestors – provide a list for tracking the ancestors of yielded elements.

find(path, namespaces=None, nsmap=None, ancestors=None)

findall(path, namespaces=None)

iter_location_hints(tag=None): Yields all schema location hints of the XML resource. If tag is not None or ‘*’, only location hints of elements whose tag equals tag are returned from the iterator.

get_namespaces(namespaces=None, root_only=None)

Extracts namespaces with related prefixes from the XML resource. If a duplicate prefix declaration is encountered and the prefix maps a different namespace, adds the namespace using a different generated prefix. The empty prefix ‘’ is used only if it’s declared at root level to avoid erroneous mapping of local names. In other cases uses ‘default’ prefix as substitute.

Parameters

namespaces – builds the namespace map starting over the dictionary provided.
root_only – if True, or None and the resource is lazy, extracts only the namespaces declared in the root element.

Returns

a dictionary for mapping namespace prefixes to full URI.

get_locations(locations=None, root_only=None)

Extracts a list of schema location hints from the XML resource. The locations are normalized using the base URL of the instance.

Parameters

locations – a sequence of schema location hints inserted before the ones extracted from the XML resource. Locations passed within a tuple container are not normalized.
root_only – if True, or if None and the resource is lazy, extracts the location hints of the root element only.

Returns

a list of couples containing normalized location hints.

class XmlDocument(source, schema=None, cls=None, validation='strict', namespaces=None, locations=None, base_url=None, allow='all', defuse='remote', timeout=300, lazy=False)

An XML document bound with its schema. If no schema is get from the provided context and validation argument is ‘skip’ the XML document is associated with a generic schema, otherwise a ValueError is raised.

Parameters

source – a string containing XML data or a file path or an URL or a file like object or an ElementTree or an Element.
schema – can be a xmlschema.XMLSchema instance or a file-like object or a file path or an URL of a resource or a string containing the XSD schema.
cls – class to use for building the schema instance (for default XMLSchema10 is used).
validation – the XSD validation mode to use for validating the XML document, that can be ‘strict’ (default), ‘lax’ or ‘skip’.
namespaces – is an optional mapping from namespace prefix to URI.
locations – resource location hints, that can be a dictionary or a sequence of couples (namespace URI, resource URL).
base_url – the base URL for base xmlschema.XMLResource initialization.
allow – the security mode for base xmlschema.XMLResource initialization.
defuse – the defuse mode for base xmlschema.XMLResource initialization.
timeout – the timeout for base xmlschema.XMLResource initialization.
lazy – the lazy mode for base xmlschema.XMLResource initialization.

class Wsdl11Document(source, cls=None, validation='strict', namespaces=None, maps=None, locations=None, base_url=None, allow='all', defuse='remote', timeout=300)

Class for WSDL 1.1 documents.

Parameters

source – a string containing XML data or a file path or an URL or a file like object or an ElementTree or an Element.
cls – class to use for building the schema instance (for default XMLSchema10 is used).
validation – the XSD validation mode to use for validating the XML document, that can be ‘strict’ (default), ‘lax’ or ‘skip’.
maps – WSDL definitions shared maps.
namespaces – is an optional mapping from namespace prefix to URI.
locations – resource location hints, that can be a dictionary or a sequence of couples (namespace URI, resource URL).
base_url – the base URL for base xmlschema.XMLResource initialization.
allow – the security mode for base xmlschema.XMLResource initialization.
defuse – the defuse mode for base xmlschema.XMLResource initialization.
timeout – the timeout for base xmlschema.XMLResource initialization.

messages: WSDL 1.1 messages.

port_types: WSDL 1.1 port types.

bindings: WSDL 1.1 bindings.

services: WSDL 1.1 services.

XPath API

Implemented through a mixin class on XSD schemas and elements.

class ElementPathMixin

Mixin abstract class for enabling ElementTree and XPath API on XSD components.

Variables

text – the Element text, for compatibility with the ElementTree API.
tail – the Element tail, for compatibility with the ElementTree API.

tag: Alias of the name attribute. For compatibility with the ElementTree API.

attrib: Returns the Element attributes. For compatibility with the ElementTree API.

get(key, default=None): Gets an Element attribute. For compatibility with the ElementTree API.

iter(tag=None): Creates an iterator for the XSD element and its subelements. If tag is not None or ‘*’, only XSD elements whose matches tag are returned from the iterator. Local elements are expanded without repetitions. Element references are not expanded because the global elements are not descendants of other elements.

iterchildren(tag=None): Creates an iterator for the child elements of the XSD component. If tag is not None or ‘*’, only XSD elements whose name matches tag are returned from the iterator.

find(path, namespaces=None)

Finds the first XSD subelement matching the path.

Parameters

path – an XPath expression that considers the XSD component as the root element.
namespaces – an optional mapping from namespace prefix to namespace URI.

Returns

The first matching XSD subelement or None if there is not match.

findall(path, namespaces=None)

Finds all XSD subelements matching the path.

Parameters

path – an XPath expression that considers the XSD component as the root element.
namespaces – an optional mapping from namespace prefix to full name.

Returns

a list containing all matching XSD subelements in document order, an empty list is returned if there is no match.

iterfind(path, namespaces=None)

Creates and iterator for all XSD subelements matching the path.

Parameters

path – an XPath expression that considers the XSD component as the root element.
namespaces – is an optional mapping from namespace prefix to full name.

Returns

an iterable yielding all matching XSD subelements in document order.

Validation API

Implemented for XSD schemas, elements, attributes, types, attribute groups and model groups.

class ValidationMixin

Mixin for implementing XML data validators/decoders. A derived class must implement the methods iter_decode and iter_encode.

is_valid(source, use_defaults=True, namespaces=None)

Like validate() except that do not raises an exception but returns True if the XML document is valid, False if it’s invalid.

Parameters

source – the source of XML data. For a schema can be a path to a file or an URI of a resource or an opened file-like object or an Element Tree instance or a string containing XML data. For other XSD components can be a string for an attribute or a simple type validators, or an ElementTree’s Element otherwise.
use_defaults – indicates whether to use default values for filling missing data.
namespaces – is an optional mapping from namespace prefix to URI.

validate(source, use_defaults=True, namespaces=None)

Validates an XML data against the XSD schema/component instance.

Parameters

source – the source of XML data. For a schema can be a path to a file or an URI of a resource or an opened file-like object or an Element Tree instance or a string containing XML data. For other XSD components can be a string for an attribute or a simple type validators, or an ElementTree’s Element otherwise.
use_defaults – indicates whether to use default values for filling missing data.
namespaces – is an optional mapping from namespace prefix to URI.

Raises

XMLSchemaValidationError if XML data instance is not a valid.

decode(source, validation='strict', **kwargs)

Decodes XML data.

Parameters

source – the XML data. Can be a string for an attribute or for a simple type components or a dictionary for an attribute group or an ElementTree’s Element for other components.
validation – the validation mode. Can be ‘lax’, ‘strict’ or ‘skip.
kwargs – optional keyword arguments for the method iter_decode().

Returns

a dictionary like object if the XSD component is an element, a group or a complex type; a list if the XSD component is an attribute group; a simple data type object otherwise. If validation argument is ‘lax’ a 2-items tuple is returned, where the first item is the decoded object and the second item is a list containing the errors.

Raises

XMLSchemaValidationError if the object is not decodable by the XSD component, or also if it’s invalid when validation='strict' is provided.

iter_decode(source, validation='lax', **kwargs)

Creates an iterator for decoding an XML source to a Python object.

Parameters

source – the XML data source.
validation – the validation mode. Can be ‘lax’, ‘strict’ or ‘skip.
kwargs – keyword arguments for the decoder API.

Returns

Yields a decoded object, eventually preceded by a sequence of validation or decoding errors.

iter_encode(obj, validation='lax', **kwargs)

Creates an iterator for Encode data to an Element.

Parameters

obj – The data that has to be encoded.
validation – The validation mode. Can be ‘lax’, ‘strict’ or ‘skip’.
kwargs – keyword arguments for the encoder API.

Returns

Yields an Element, eventually preceded by a sequence of validation or encoding errors.

iter_errors(source, use_defaults=True, namespaces=None)

Creates an iterator for the errors generated by the validation of an XML data against the XSD schema/component instance.

Parameters

source – the source of XML data. For a schema can be a path to a file or an URI of a resource or an opened file-like object or an Element Tree instance or a string containing XML data. For other XSD components can be a string for an attribute or a simple type validators, or an ElementTree’s Element otherwise.
use_defaults – Use schema’s default values for filling missing data.
namespaces – is an optional mapping from namespace prefix to URI.

encode(obj, validation='strict', **kwargs)

Encodes data to XML.

Parameters

obj – the data to be encoded to XML.
validation – the validation mode. Can be ‘lax’, ‘strict’ or ‘skip.
kwargs – optional keyword arguments for the method iter_encode().

Returns

An element tree’s Element if the original data is a structured data or a string if it’s simple type datum. If validation argument is ‘lax’ a 2-items tuple is returned, where the first item is the encoded object and the second item is a list containing the errors.

Raises

XMLSchemaValidationError if the object is not encodable by the XSD component, or also if it’s invalid when validation='strict' is provided.

iter_encode(obj, validation='lax', **kwargs)

Creates an iterator for Encode data to an Element.

Parameters

obj – The data that has to be encoded.
validation – The validation mode. Can be ‘lax’, ‘strict’ or ‘skip’.
kwargs – keyword arguments for the encoder API.

Returns

Yields an Element, eventually preceded by a sequence of validation or encoding errors.

Particles API

Implemented for XSD model groups, elements and element wildcards.

class ParticleMixin(min_occurs=1, max_occurs: Optional[int] = 1)

Mixin for objects related to XSD Particle Schema Components:

https://www.w3.org/TR/2012/REC-xmlschema11-1-20120405/structures.html#p https://www.w3.org/TR/2012/REC-xmlschema11-1-20120405/structures.html#t

Variables

min_occurs – the minOccurs property of the XSD particle. Defaults to 1.
max_occurs – the maxOccurs property of the XSD particle. Defaults to 1, a None value means ‘unbounded’.

is_empty(): Tests if max_occurs == 0. A zero-length model group is considered empty.

is_emptiable(): Tests if max_occurs == 0. A zero-length model group is considered emptiable. For model groups the test outcome depends also on nested particles.

is_single(): Tests if the particle has max_occurs == 1. For elements the test outcome depends also on parent group. For model groups the test outcome depends also on nested model groups.

is_multiple(): Tests the particle can have multiple occurrences.

is_ambiguous(): Tests if min_occurs != max_occurs.

is_univocal(): Tests if min_occurs == max_occurs.

is_missing(occurs: int): Tests if provided occurrences are under the minimum.

is_over(occurs: int): Tests if provided occurrences are over the maximum.

Main XSD components

class XsdComponent(elem, schema, parent=None, name: Optional[str] = None)

Class for XSD components. See: https://www.w3.org/TR/xmlschema-ref/

Parameters

elem – ElementTree’s node containing the definition.
schema – the XMLSchema object that owns the definition.
parent – the XSD parent, None means that is a global component that has the schema as parent.
name – name of the component, maybe overwritten by the parse of the elem argument.

Variables

qualified (bool) – for name matching, unqualified matching may be admitted only for elements and attributes.

target_namespace: Property that references to schema’s targetNamespace.

local_name: The local part of the name of the component, or None if the name is None.

qualified_name: The name of the component in extended format, or None if the name is None.

prefixed_name: The name of the component in prefixed format, or None if the name is None.

is_global(): Returns True if the instance is a global component, False if it’s local.

is_matching(name, default_namespace=None, **kwargs)

Returns True if the component name is matching the name provided as argument, False otherwise. For XSD elements the matching is extended to substitutes.

Parameters

name – a local or fully-qualified name.
default_namespace – used if it’s not None and not empty for completing the name argument in case it’s a local name.
kwargs – additional options that can be used by certain components.

tostring(indent='', max_lines=None, spaces_for_tab=4): Serializes the XML elements that declare or define the component to a string.

class XsdType(elem, schema, parent=None, name: Optional[str] = None)

Common base class for XSD types.

simple_type: Property that is the instance itself for a simpleType. For a complexType is the instance’s content if this is a simpleType or None if the instance’s content is a model group.

model_group: Property that is None for a simpleType. For a complexType is the instance’s content if this is a model group or None if the instance’s content is a simpleType.

has_complex_content(): Returns True if the instance is a complexType with mixed or element-only content, False otherwise.

has_mixed_content(): Returns True if the instance is a complexType with mixed content, False otherwise.

has_simple_content(): Returns True if the instance has a simple content, False otherwise.

static is_atomic(): Returns True if the instance is an atomic simpleType, False otherwise.

static is_complex(): Returns True if the instance is a complexType, False otherwise.

static is_datetime(): Returns True if the instance is a datetime/duration XSD builtin-type, False otherwise.

is_element_only(): Returns True if the instance is a complexType with element-only content, False otherwise.

is_emptiable(): Returns True if the instance has an emptiable value or content, False otherwise.

is_empty(): Returns True if the instance has an empty content, False otherwise.

static is_list(): Returns True if the instance is a list simpleType, False otherwise.

static is_simple(): Returns True if the instance is a simpleType, False otherwise.

class XsdElement(elem, schema, parent)

Class for XSD 1.0 element declarations.

Variables

type – the XSD simpleType or complexType of the element.
attributes – the group of the attributes associated with the element.

class XsdAttribute(elem, schema, parent=None, name: Optional[str] = None)

Class for XSD 1.0 attribute declarations.

Variables: type – the XSD simpleType of the attribute.

Other XSD components

Elements and attributes

class Xsd11Element(elem, schema, parent): Class for XSD 1.1 element declarations.

class Xsd11Attribute(elem, schema, parent=None, name: Optional[str] = None): Class for XSD 1.1 attribute declarations.

Types

class Xsd11ComplexType(elem, schema, parent, name=None, **kwargs): Class for XSD 1.1 complexType definitions.

class XsdComplexType(elem, schema, parent, name=None, **kwargs)

Class for XSD 1.0 complexType definitions.

Variables

attributes – the attribute group related with the complexType.
content – the content of the complexType can be a model group or a simple type.
mixed – if True the complex type has mixed content.

content_type: Property that returns the attribute content, for backward compatibility.

class XsdSimpleType(elem, schema, parent, name=None, facets=None)

Base class for simpleTypes definitions. Generally used only for instances of xs:anySimpleType.

enumeration

max_value

min_value

class XsdAtomicBuiltin(elem, schema, name, python_type, base_type=None, admitted_facets=None, facets=None, to_python=None, from_python=None)

Class for defining XML Schema built-in simpleType atomic datatypes. An instance contains a Python’s type transformation and a list of validator functions. The ‘base_type’ is not used for validation, but only for reference to the XML Schema restriction hierarchy.

Type conversion methods:

to_python(value): Decoding from XML
from_python(value): Encoding to XML

class XsdList(elem, schema, parent, name=None): Class for ‘list’ definitions. A list definition has an item_type attribute that refers to an atomic or union simpleType definition.

class Xsd11Union(elem, schema, parent, name=None)

class XsdUnion(elem, schema, parent, name=None): Class for ‘union’ definitions. A union definition has a member_types attribute that refers to a ‘simpleType’ definition.

class Xsd11AtomicRestriction(elem, schema, parent, name=None, facets=None, base_type=None): Class for XSD 1.1 atomic simpleType and complexType’s simpleContent restrictions.

class XsdAtomicRestriction(elem, schema, parent, name=None, facets=None, base_type=None): Class for XSD 1.0 atomic simpleType and complexType’s simpleContent restrictions.

Attribute and model groups

class XsdAttributeGroup(elem, schema, parent, derivation=None, base_attributes=None): Class for XSD attributeGroup definitions.

class Xsd11Group(elem, schema, parent): Class for XSD 1.1 model group definitions.

class XsdGroup(elem, schema, parent): Class for XSD 1.0 model group definitions.

Wildcards

class Xsd11AnyElement(elem, schema, parent, maps=None): Class for XSD 1.1 any declarations.

class XsdAnyElement(elem, schema, parent, maps=None): Class for XSD 1.0 any wildcards.

class Xsd11AnyAttribute(elem, schema, parent=None, name: Optional[str] = None): Class for XSD 1.1 anyAttribute declarations.

class XsdAnyAttribute(elem, schema, parent=None, name: Optional[str] = None): Class for XSD 1.0 anyAttribute wildcards.

class XsdOpenContent(elem, schema, parent): Class for XSD 1.1 openContent model definitions.

class XsdDefaultOpenContent(elem, schema): Class for XSD 1.1 defaultOpenContent model definitions.

Identity constraints

class XsdIdentity(elem, schema, parent)

Common class for XSD identity constraints.

Variables

selector – the XPath selector of the identity constraint.
fields – a list containing the XPath field selectors of the identity constraint.

class XsdSelector(elem, schema, parent): Class for defining an XPath selector for an XSD identity constraint.

class XsdFieldSelector(elem, schema, parent): Class for defining an XPath field selector for an XSD identity constraint.

class Xsd11Unique(elem, schema, parent)

class XsdUnique(elem, schema, parent)

class Xsd11Key(elem, schema, parent)

class XsdKey(elem, schema, parent)

class Xsd11Keyref(elem, schema, parent)

class XsdKeyref(elem, schema, parent)

Implementation of xs:keyref.

Variables: refer – reference to a xs:key declaration that must be in the same element or in a descendant element.

Others

class XsdAssert(elem, schema, parent, base_type): Class for XSD assert constraint definitions.

class XsdAlternative(elem, schema, parent): XSD 1.1 type alternative definitions.

class XsdNotation(elem, schema, parent=None, name: Optional[str] = None): Class for XSD notation declarations.

class XsdAnnotation(elem, schema, parent=None, name: Optional[str] = None)

Class for XSD annotation definitions.

Variables

appinfo – a list containing the xs:appinfo children.
documentation – a list containing the xs:documentation children.

Package API

Errors and exceptions

Document level API

Schema level API

Global maps API

Converters API

XML resources API

XPath API

Validation API

Particles API

Main XSD components

Other XSD components

Elements and attributes

Types

Attribute and model groups

Wildcards

Identity constraints

Facets

Others