Missing element in SOAP API request using Python's Zeep, but the element is in the request dictionary

i'm using Zeep to interact with Workday's SOAP API to edit a someone's Workday username. Here is the following request body to the Human Resources WSDL, v37.2

    request_dict = {
        "Workday_Account_for_Worker_Update": {
            "Worker_Reference": {
                "Employee_Reference": {
                    "Integration_ID_Reference": {
                        "ID": {
                            "type": "WD-EMPLID",
                            "_value_1": user_id
                        }
                    }
                }
            },
            "Workday_Account_for_Worker_Data": {
                "User_Name": username
            }
        }
    }
    response = client.service.Update_Workday_Account(request_dict)

The error message i receive is zeep.exceptions.ValidationError: Missing element Workday_Account_for_Worker_Data (Workday_Account_for_Worker_Update.Workday_Account_for_Worker_Data), but the element is clearly there. Anyone have any idea what I'm doing wrong?

You are not using the correct method signature to perform the call.

If you do a:

python -mzeep https://community.workday.com/sites/default/files/file-hosting/productionapi/Human_Resources/v37.2/Human_Resources.wsdl > output.txt

and you look inside the produced output.txt file, you will see that Update_Workday_Account has this signature:

Update_Workday_Account(
  Worker_Reference: ns0:Worker_ReferenceType,
  Non_Worker_Reference: ns0:RoleObjectType,
  Workday_Account_for_Worker_Data: ns0:Workday_Account_for_Worker_DataType, 
  version: xsd:string, 
  _soapheaders={header: ns0:Workday_Common_HeaderType}
) -> None

so your code should probably be something like this:

worker_reference = {
    "Employee_Reference": {
        "Integration_ID_Reference": {
            "ID": {
                "type": "WD-EMPLID",
                "_value_1": user_id
            }
        }
    }
}

workday_account_for_worker_data = {
    "User_Name": username
}

client.service.Update_Workday_Account(worker_reference, None, workday_account_for_worker_data)

I can't really test the call from my side so you should substitute appropriate parameters on your side before making the request.