The xml.dom.minidom package has as a xml.toprettyxml() function that has the problem of altering the whitespace of the text of elements.   The ElementTree module needs a prettify option that works better, perhaps something based of Effbot's code at:

http://effbot.org/zone/element-lib.htm#prettyprint

The lxml package also provides an API for this purpose:

    print(etree.tostring(root, pretty_print=True))