How to serialize initialized object in Python into XML?

Question

I am pretty new to python. I now how to marshall/unmarshall objects in Java. I am looking for something like we did it in Java. Like:

JAXBContext jaxbContext = JAXBContext.newInstance(com.Request1.class);
                Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
                DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
                dbf.setNamespaceAware(true);
                DocumentBuilder db = dbf.newDocumentBuilder();
                Document doc = db.parse(new InputSource(new StringReader(message)));

                requestStr2 = (com.Request1) unmarshaller.unmarshal(doc);

Where Request1 has @XmlRootElement annotation.

I don't want to write multiple elements, subelements etc, because i have very complex xsd structure. I want to generate classes from xsd by generateDS, then initialize it from database and serialize to xml-file

I saw pyxser, but it is only on python 2. What modules could help me with that? Thank you

Do you have to use XML? If not then maybe the built-in `pickle` module could help you? — Tom Dalton, Oct 29 '19 at 15:38

CodeMonkey · Answer 1 · 2020-12-29T22:35:33.900

The generateDS generated python-modules can parse a XML instance of XML Schema from file or from string. The generateDS module supports complex XML Schemas including complex types, abstract types, enumerated lists, mixed content, etc.

For example, here is the command for generateDS to generate a python module called people.py from people.xsd.

python generateDS.py -o people.py people.xsd

On Windows, there is a generateDS.exe wrapper that can be called as a short-cut:

generateDS.exe -o people.py people.xsd

This is an example XML instance conforming to the people.xsd schema.

<people xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <person id="1">
        <name>Alberta</name>
    </person> 
    <person id="2">
        <name>Bernardo</name>
    </person> 
    ...
</people>

The following is a snippet of python to parse the above XML instance in file named people.xml that conforms to the XML Schema. The parse() function parses the XML document from a file and creates object structure for classes associated with the elements.

import people as p
people = p.parse("people.xml", silence=True)
# iterate over each person in the collection
for person in people.get_person():
    print(person.name)

If wanted to parse from a string variable xml then call the parseString() function on it.

people = p.parseString(xml, silence=True)

Note if the XML content contains encoding declaration then must use bytes input such as doing the following.

people = p.parseString(str.encode(xml), silence=True)

See tutorial for details (and more examples) to create a python module from an XML Schema.

How to serialize initialized object in Python into XML?

1 Answers1