Remove "ds:" in signed XML tree namespace in python's signxml

Question

I am working with Python's lxml and signxml to generate an xml file and sign it with a pem certificate and private key. I am also required to validate the signed xml file with an XSD file.

I will not focus much on the generated xml file with lxml. My code to sign the xml file has the following form:

    def _get_xml_tree_root(self):
        root = ET.Element('facturaElectronicaCompraVenta' , attrib={location_attribute: invoice_sector + '.xsd'})
        xml_header = ET.SubElement(root, 'header')
        xml_detail = ET.SubElement(root, 'detail')
      return root

    def _get_signed_xml(self):
        signed_root = XMLSigner().sign(
            self._get_xml_tree_root(),
            key=base64.b64decode(io.TextIOWrapper(BytesIO(electronic_key)).read()),
            cert=base64.b64decode(io.TextIOWrapper(BytesIO(electronic_certificate)).read())
        )
        return signed_root

My problem is that the xml file that I generate in the signature section has following form:

<facturaElectronicaCompraVenta xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="facturaElectronicaCompraVenta.xsd">
   <header></header>
   <detail></detail>
    <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
        <ds:SignedInfo>
            <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2006/12/xml-c14n11"/>
            <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/>
            <ds:Reference URI="">
                <ds:Transforms>
                    <ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
                    <ds:Transform Algorithm="http://www.w3.org/2006/12/xml-c14n11"/>
                </ds:Transforms>
                <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
                <ds:DigestValue>KvIMPxajMb98G3+HdSLg1/pgSyisLp4OWZt6Gxhe+/c=</ds:DigestValue>
            </ds:Reference>
        </ds:SignedInfo>
        <ds:SignatureValue>Bv9W9cGyXvX4QeDDb61YME8TbnFlBOVBw2Iiv+a+7VrxjoH4z8kLO4rgonXbqGuk2DKrR4ACqoFQNd/9/lJb31TDk2SjegURBsjP9gLvFWwfq99jh6zn6rPF/gwqd+lA1ruGpDT/Q+vxMXeNpXfk+nDcgdDJoP1bpDEPHbSHGkQu2SX1NQP1SlRZkNoJXxorFfbTDmm1/VFRsv5uBNQvf7hSxTEvvLW8WVYN271iTzHTpAnbyg7VTeys/Ca2FQsZ95hgCHfKsOHEX2/HtxpkGtXDjJKPHq43M2MR3Bp9+YUBAxcj5WMsGcs0lp7hFP6xADEJAcLdfta3SJCdNTa0Vw==</ds:SignatureValue>
        <ds:KeyInfo>
            <ds:X509Data>
                <ds:X509Certificate>
                   CertificateStuff...
                </ds:X509Certificate>
            </ds:X509Data>
        </ds:KeyInfo>
    </ds:Signature>
</facturaElectronicaCompraVenta>

And the XSD file is expecting the xml file like the following:

<facturaElectronicaCompraVenta xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="facturaElectronicaCompraVenta.xsd">
   <header></header>
   <detail></detail>
   <Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
       <SignedInfo>
           <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
           <SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/>
           <Reference URI="">
               <Transforms>
                   <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
                   <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments"/>
               </Transforms>
               <DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
            <DigestValue>WmFvnKBZIr9D37PaYuxM3aoXVu9nDZT+2MI1I+RUh8s=  </DigestValue>
       </Reference>
       </SignedInfo>
       <SignatureValue> itb123fGGhh12DpFDFas34ASDAPpSSSSadasDasAS1smkRsj5ksdjasd8asdkasjd8asdkas8asdk21v a1qf+kBKLwF39mj+5zKo1qf+kBKLD42qD/+yxSMMS6DM5SywPxO1oyjnSZtObIe/45fdS4sE9+aNOn UncYUlSDAPpSSSSadasgIMWwlX2XMJ4SDAPpSSSSadas6qihJt/3dEIdta1RETSDAPpSSSSadas9S2W ALbT3VV8pjLqikVLcSDAPpSSSSadaseCKG8abcdssM0Wm8p+5grNNpSDAPpSSSSadasy4TvT4C3xS 70zSbKWeBUUglRcU8FECEcacu+UJaBCgRW0S3Q== </SignatureValue>
       <KeyInfo>
           <X509Data>
               <X509Certificate>
                  CertificateStuff..
               </X509Certificate>
           </X509Data>
       </KeyInfo>
   </Signature>
</facturaElectronicaCompraVenta>

I believe that the XSD file is rejecting the "ds:" part. I have previously struggled with xml namespaces and I do not understand them very well.

But, how could I remove the "ds:" namespace by also changing the "xmlns:ds=" to "xmlns="?