Lib to generate XML/JSON[P] output from a DTD/XSD/JSON Schema/etc

[Acácio Centeno]

Hi, I've searched both this group and the web but was unable to find an answer, sorry if it has already been answered, it seems such a common problem that I’m sure someone has asked before.

We have a WebServices platform that must reply in XML, JSON, or JSONP. Having to convert between these formats is a really pain in the neck.

What I’d like to do is, given some schema representation, that could be a DTD, XSD or whatever and a python dictionary with the values for each node, generate the output in either XML, JSON or JSONP.

For instance, if the XSD would be:
<?xml version="1.0" encoding="utf-8"?>
<xs:schema elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="Foo"></xs:element>
  <xs:element name="Baz"></xs:element>
  <xs:element name="Choice" minOccurs="0">
          <xs:simpleType>
            <xs:restriction base="xs:string">
              <xs:enumeration value="A" />
              <xs:enumeration value="B" />
              <xs:enumeration value="C" />
              <xs:enumeration value="D" />
            </xs:restriction>
          </xs:simpleType>
        </xs:element>
</xs:schema>

And given the following dict:

{
	“foo”: “bar”,
	“hello”: “world”,
	“choice”: “B”,
	“callback”: “process_server_reply”
}

Be able to generate either this XML:

<xml>
	<Foo>Bar</Foo>
	<Hello>World</Hello>
	<Choice>B</Choice>
</xml>

Or this JSON:

{
   "foo": "bar",
   "hello": "world",
   "choice": "B"
}

Or this JSONP:

process_server_reply({"foo": "bar","hello": "world","choice": "B"});


Which library/technique would you guys recommend for this kind of scenario?

Thanks in advance.