Here's an article about Python and Java dirtSimple.org: Python Is Not Java from Phillip J. Eby which rang true for me in a few places.
One of the things he mentions in this article is XML and how in a clamour to get on the bandwagon people use XML in places where it's really not helpful.
XML is great for interoperability but if you're just storing data or moving data around inside your application, you don't need XML. XML comes with a price tag in performance. It needs to be parsed.
If your language of choice is capable of doing the data work on it's own (*get python*, *get python*) then use that.
Don't get me wrong, I love XML and coming from a few projects where I had to deal with EDI formatted data, XML is a blessing.
XML is also a darling of computing media and of the big guys, and although it has a nice ring to it, remember, it's not magical, its a file format.