If you know where to find the information it becomes quite straight forward if you are not doing anything complex. With python you can use xml.dom.minidom, while with maxscript you can use either .NET Object “System.Xml.XmlDocument” or Class “System.Xml.XmlReader“.
With python you create a root element and append child elements from there. A very good sample can be found on: http://www.postneo.com/projects/pyxml/ To read you have getElementsByTagName on both python and dotnet XmlDocument. XmlReader might be a bit faster, but you have to parse elements by yourself.
There’s an issue with minidom’s toprettyprintxml, it adds whitespace and tabs between tags, around textNodes. And they are obviously read afterwards. A couple of different solutions are discussed on Ron Rothman’s blog, the easiest one using xml.dom.ext.PrettyPrint.