How to generate XML documents with namespaces in Python

Question

I'm trying to generate an XML document with namespaces, currently with Python's xml.dom.minidom:

import xml.dom.minidom doc = xml.dom.minidom.Document() el = doc.createElementNS('http://example.net/ns', 'el') doc.appendChild(el) print(doc.toprettyxml()) 

The namespace is saved (doc.childNodes[0].namespaceURI is 'http://example.net/ns'), but why is it missing in the output?

<?xml version="1.0" ?> <el/> 

I expect:

<?xml version="1.0" ?> <el xmlns="http://example.net/ns" /> 

or

<?xml version="1.0" ?> <randomid:el xmlns:randomid="http://example.net/ns" /> 

Answer 1

createElementNS() is defined as:

def createElementNS(self, namespaceURI, qualifiedName):     prefix, localName = _nssplit(qualifiedName)     e = Element(qualifiedName, namespaceURI, prefix)     e.ownerDocument = self     return e 

so…

import xml.dom.minidom doc = xml.dom.minidom.Document() el = doc.createElementNS('http://example.net/ns', 'ex:el') #--------------------------------------------------^^^^^ doc.appendChild(el) print(doc.toprettyxml()) 

yields:

<?xml version="1.0" ?> <ex:el/> 

…not quite there…

import xml.dom.minidom doc = xml.dom.minidom.Document() el = doc.createElementNS('http://example.net/ns', 'ex:el') el.setAttribute("xmlns:ex", "http://example.net/ns") doc.appendChild(el) print(doc.toprettyxml()) 

yields:

<?xml version="1.0" ?> <ex:el xmlns:ex="http://example.net/ns"/> 

alternatively:

import xml.dom.minidom doc = xml.dom.minidom.Document() el = doc.createElementNS('http://example.net/ns', 'el') el.setAttribute("xmlns", "http://example.net/ns") doc.appendChild(el) print(doc.toprettyxml()) 

wich produces:

<?xml version="1.0" ?> <el xmlns="http://example.net/ns"/> 

It looks like you'd have to do it manually. Element.writexml() shows no indication that namespaces would get any special treatment.

EDIT: This answer is targeted at xml.dom.minidom only, since the OP used it in the question. I do not indicate that it was impossible to use XML namespaces in Python generally. ;-)