Element is generated as List, while it is 0:1

[skinkie]

Within the NeTEx schema the element TransportAdministrativeZone inherits a Description element. This Description element is rendered as List[MultilingualString]. It is unclear to me why this element is not just a single element.

@dataclass(unsafe_hash=True, kw_only=True)
class GroupOfEntitiesVersionStructure(DataManagedObjectStructure):
    """
    Type for a GROUP OF ENTITies.

    :ivar name: Name of GROUP OF ENTITies.
    :ivar short_name: Short Name of GROUP OF ENTITies.
    :ivar description: Further Description of a GROUP OF ENTITies.
    :ivar purpose_of_grouping_ref: Reference to a PURPOSE OF GROUPING.
    :ivar private_code:
    :ivar info_links: Hyperlinks associated with GROUP OF ENTITIES.
    """
    class Meta:
        name = "GroupOfEntities_VersionStructure"

    description: List[MultilingualString] = field(
        default_factory=list,
        metadata={
            "name": "Description",
            "type": "Element",
            "namespace": "http://www.netex.org.uk/netex",
        }
    )

NeTEx-CEN/NeTEx#562

[tefra]

Mypy doesn't allow an override field to change from a single value to a list like this

@dataclass
class Foo:
    value: str

@dataclass
class Bar(Foo):
    value: list[str]

To compensate xsdata, finds these cases and converts the parent class to a list, the culprit for the change in GroupOfEntities_VersionStructure is the HeadwayJourneyGroup, which has two sequences that both include a description.

	<xsd:element name="HeadwayJourneyGroup" abstract="false" substitutionGroup="JourneyFrequencyGroup">
		<xsd:annotation>
			<xsd:documentation>A group of VEHICLE JOURNEYs following the same JOURNEY PATTERN and having the same headway interval between a specified start and end time (for example, ‘every 10 minutes’). This is especially useful for presenting passenger information.</xsd:documentation>
		</xsd:annotation>
		<xsd:complexType>
			<xsd:complexContent>
				<xsd:restriction base="HeadwayJourneyGroup_VersionStructure">
					<xsd:sequence>
						<xsd:sequence>
							<xsd:group ref="EntityInVersionGroup" minOccurs="0"/>
						</xsd:sequence>
						<xsd:sequence>
							<xsd:group ref="DataManagedObjectGroup"/>
						</xsd:sequence>
						<xsd:sequence>
							<xsd:group ref="GroupOfEntitiesGroup"/>  <!-- this has a description element -->
						</xsd:sequence>
						<xsd:group ref="JourneyFrequencyGroupGroup"/>
						<xsd:group ref="HeadwayJourneyGroupGroup"/><!-- this has a description element -->
					</xsd:sequence>
					<xsd:attribute name="id" type="HeadwayJourneyGroupIdType"/>
				</xsd:restriction>
			</xsd:complexContent>
		</xsd:complexType>

Here is the hack in the code
https://github.com/tefra/xsdata/blob/main/xsdata/codegen/handlers/validate_attributes_overrides.py#L53-L55

At the time I couldn't think of a better alternative, I am open to suggestions.

Note to Self: Add a warning there because you need to know all xsdata's hacks to debug this one.

[tefra]

A new warning was added, if anyone comes up with an idea to address things properly please open a new issue