Problems with namespace selection

[s2bjni]

Use case

We have a WSDL, which has "document types". These document types have different structures, but different document types can have same top level elements tags with different namespaces. We have a pydantic BaseModel adapter which is used to create the dictionary and then will be used with zeep.

class Payload(_pydantic.BaseModel):
    MasterDataContractEventMessage: Union[MasterDataContractEventMessageCls_F04, MasterDataContractEventMessageCls_F06, MasterDataContractEventMessageCls_F18, MasterDataContractEventMessageCls_F27, None]

This is converted to dictionary and when creating the XML, it should create one these elements defined in the WSDL:

<urn11:MasterDataContractEventMessage wsu:Id="?">
    <urn11:MasterDataContractEvent>
        ...
    </urn11:MasterDataContractEvent>
</urn11:MasterDataContractEventMessage>

<urn13:MasterDataContractEventMessage wsu:Id="?">
    <urn13:MasterDataContractEvent>
        ...
    </urn13:MasterDataContractEvent>
</urn13:MasterDataContractEventMessage>

<urn15:MasterDataContractEventMessage wsu:Id="?">
    <urn15:MasterDataContractEvent>
        ...
    </urn15:MasterDataContractEvent>
</urn15:MasterDataContractEventMessage>

Problem/Bug

Creating the XML results this, which means that the top level element type for MasterDataContractMessage is chosen from wrong namespace:

<urn11:MasterDataContractEventMessage>
    <urn13:MasterDataContractEvent>
        ...
    </urn13:MasterDataContractEvent>
</urn11:MasterDataContractEventMessage>

Defining the correct namespace with correct element type leads to this:

<ns0:MasterDataContractEventMessage xmlns:ns0="urn:fi:Datahub:mif:masterdata:F04_MasterDataContractEvent:v1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="urn13:MasterDataContractEventMessage_Type">
    <urn13:MasterDataContractEvent>
    </urn13:MasterDataContractEvent>
</ns0:MasterDataContractEventMessage>

The WSDL has the schema as:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:rsm="urn:fi:Datahub:mif:test:ProcessMessageRequestMessage:v1" xmlns:abie="urn:fi:Datahub:mif:common:v1"  targetNamespace="urn:fi:Datahub:mif:test:ProcessMessageRequestMessage:v1" 
 xmlns:F04="urn:fi:Datahub:mif:masterdata:F04_MasterDataContractEvent:v1"
 xmlns:F06="urn:fi:Datahub:mif:masterdata:F06_MasterDataContractEvent:v1"
 xmlns:F18="urn:fi:Datahub:mif:masterdata:F18_MasterDataContractEvent:v1"
 elementFormDefault="qualified" attributeFormDefault="unqualified"  version="2.4.0.0">

<xs:import namespace="urn:fi:Datahub:mif:masterdata:F04_MasterDataContractEvent:v1"   schemaLocation="../../masterdata/F04_MasterDataContractEvent.xsd"/>
<xs:import namespace="urn:fi:Datahub:mif:masterdata:F06_MasterDataContractEvent:v1"   schemaLocation="../../masterdata/F06_MasterDataContractEvent.xsd"/>
<xs:import namespace="urn:fi:Datahub:mif:masterdata:F18_MasterDataContractEvent:v1"   schemaLocation="../../masterdata/F18_MasterDataContractEvent.xsd"/>

<xs:complexType name="ProcessMessageRequestMessage_Type">
  <xs:choice maxOccurs="1">
    <xs:element  ref="F04:MasterDataContractEventMessage" minOccurs="1" maxOccurs="1"/>
    <xs:element  ref="F06:MasterDataContractEventMessage" minOccurs="1" maxOccurs="1"/>
    <xs:element  ref="F18:MasterDataContractEventMessage" minOccurs="1" maxOccurs="1"/>
  </xs:choice>
</xs:complexType>

Is this a bug or would there be something we could do?