def createAppendElement(self, namespaceURI, localName, prefix=None):
        declare = False
        qualifiedName = localName
        if namespaceURI:
            try:
                prefix = self.getPrefix(namespaceURI)
            except:
                declare = True
                prefix = prefix or self._getUniquePrefix()
            if prefix: 
                qualifiedName = '%s:%s' %(prefix, localName)
        node = self.createElementNS(namespaceURI, qualifiedName)
        if declare:
            node._setAttributeNS(XMLNS.BASE, 'xmlns:%s' %prefix, namespaceURI)
        self._appendChild(node=node._getNode())
        return node
Create a new element (namespaceURI,name), append it
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/SOAPpy/wstools/Utility.py/ElementProxy.createAppendElement