Default namespace and to_xml() adds ns0 tags everywhere.

[jsenecal]

Hello there,

When using nsmap with a default namespace and using "to_xml" method, ns0: is prepended to every xml attribute. as such:

Python 3.10.6 (main, Aug 10 2022, 11:40:04) [GCC 11.3.0]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.8.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: from typing import List, Optional, Literal

In [2]: from pydantic_xml import BaseXmlModel, attr, element, wrapped

In [3]: from pydantic import HttpUrl

In [4]: class MultiLineElement(BaseXmlModel):
   ...:     number: int = attr()  # type: ignore
   ...:     line: str
   ...: 

In [5]: class PocLinkRef(BaseXmlModel):
   ...:     description: Literal["Admin", "Tech", "Routing"] = attr()  # type: ignore
   ...:     function: Literal["AD", "T", "R"] = attr()  # type: ignore
   ...:     handle: str = attr()  # type: ignore
   ...: 

In [6]: class Org(BaseXmlModel, tag="org", nsmap={"": "http://www.arin.net/regrws/core/v1"}):
   ...:     street_address: List[MultiLineElement] = wrapped('streetAddress', element(tag="line") ) # type: ignore
   ...:     city: str = element()  # type: ignore
   ...:     iso3166_2: Optional[str] = element(tag="iso3166-2")  # type: ignore
   ...:     postal_code: Optional[str] = element(tag="postalCode")  # type: ignore
   ...:     comment: Optional[List[MultiLineElement]]  = wrapped('comment', element(tag="line") )# type: ignore
   ...: 
   ...:     handle: Optional[str] = element()  # type: ignore
   ...:     registration_date: Optional[str] = element(tag="registrationDate")  # type: ignore
   ...:     org_name: str = element(tag="orgName")  # type: ignore
   ...:     dba_name: Optional[str] = element(tag="dbaName")  # type: ignore
   ...:     tax_id: Optional[str] = element(tag="taxId")  # type: ignore
   ...:     org_url: Optional[HttpUrl] = element(tag="orgUrl")  # type: ignore
   ...: 

In [7]: PAYLOAD = """
   ...:     <org xmlns="http://www.arin.net/regrws/core/v1" >
   ...:         <streetAddress>
   ...:             <line number = "1">Line 1</line>
   ...:         </streetAddress>
   ...:         <city>Chantilly</city>
   ...:         <iso3166-2>VA</iso3166-2>
   ...:         <postalCode>20151</postalCode>
   ...:         <comment>
   ...:             <line number = "1">Line 1</line>
   ...:         </comment>
   ...:         <registrationDate>Mon Nov 07 14:04:28 EST 2011</registrationDate>
   ...:         <handle>ARIN</handle>
   ...:         <orgName>ORGNAME</orgName>
   ...:         <dbaName>DBANAME</dbaName>
   ...:         <taxId>TAXID</taxId>
   ...:         <orgUrl>http://example.com/org/ARIN</orgUrl>
   ...:     </org>
   ...:     """

In [8]: org = Org.from_xml(PAYLOAD)

In [9]]: print(org.to_xml().decode())
<ns0:org xmlns:ns0="http://www.arin.net/regrws/core/v1" xmlns="http://www.arin.net/regrws/core/v1"><ns0:streetAddress><ns0:line number="1">Line 1</ns0:line></ns0:streetAddress><ns0:city>Chantilly</ns0:city><ns0:iso3166-2>VA</ns0:iso3166-2><ns0:postalCode>20151</ns0:postalCode><ns0:comment><ns0:line number="1">Line 1</ns0:line></ns0:comment><ns0:handle>ARIN</ns0:handle><ns0:registrationDate>Mon Nov 07 14:04:28 EST 2011</ns0:registrationDate><ns0:orgName>ORGNAME</ns0:orgName><ns0:dbaName>DBANAME</ns0:dbaName><ns0:taxId>TAXID</ns0:taxId><ns0:orgUrl>http://example.com/org/ARIN</ns0:orgUrl></ns0:org>

Payload:

<org xmlns="http://www.arin.net/regrws/core/v1">
  <streetAddress>
    <line number="1">Line 1</line>
  </streetAddress>
  <city>Chantilly</city>
  <iso3166-2>VA</iso3166-2>
  <postalCode>20151</postalCode>
  <comment>
    <line number="1">Line 1</line>
  </comment>
  <registrationDate>Mon Nov 07 14:04:28 EST 2011</registrationDate>
  <handle>ARIN</handle>
  <orgName>ORGNAME</orgName>
  <dbaName>DBANAME</dbaName>
  <taxId>TAXID</taxId>
  <orgUrl>http://example.com/org/ARIN</orgUrl>
</org>

Result:

<ns0:org xmlns:ns0="http://www.arin.net/regrws/core/v1" xmlns="http://www.arin.net/regrws/core/v1">
  <ns0:streetAddress>
    <ns0:line number="1">Line 1</ns0:line>
  </ns0:streetAddress>
  <ns0:city>Chantilly</ns0:city>
  <ns0:iso3166-2>VA</ns0:iso3166-2>
  <ns0:postalCode>20151</ns0:postalCode>
  <ns0:comment>
    <ns0:line number="1">Line 1</ns0:line>
  </ns0:comment>
  <ns0:handle>ARIN</ns0:handle>
  <ns0:registrationDate>Mon Nov 07 14:04:28 EST 2011</ns0:registrationDate>
  <ns0:orgName>ORGNAME</ns0:orgName>
  <ns0:dbaName>DBANAME</ns0:dbaName>
  <ns0:taxId>TAXID</ns0:taxId>
  <ns0:orgUrl>http://example.com/org/ARIN</ns0:orgUrl>
</ns0:org>

Is that intended and is there a way around this?

With many thanks,

[dapper91]

@jsenecal Hi,

This library uses xml.etree or lxml.etree as serialization backend and they redefine default namespace as nsX so I can't do anything about it. I think I found a workaround to fix that but it will only work with lxml because xml.etree doesn't provide required api.

[jsenecal]

Would you mind sharing more information about that workaround (I'm using lxml extra anyways) ? The generated XML is sent to a third party which is very picky about the format.

With regards,

[jsenecal]

Amazing @dapper91
!! Thanks for the quick fix 👍