gistfile1.py

import sys
import xml.etree.cElementTree as ET


def format_start(elem):
    attrs = ' '.join('{0}={1}'.format(k, v)
                     for k, v in elem.items())
    return ('<{tag} {attrs}>'.format(tag=elem.tag, attrs=attrs)
            if attrs else '<{tag}>'.format(tag=elem.tag))


def format_end(elem):
    return '</{0}>'.format(elem.tag)


def pretty_print(fn, indent=2):
    cursor = 0
    for event, elem in ET.iterparse(fn, events=('start', 'end')):
        if event == 'start':
            print ' ' * cursor, format_start(elem)
            cursor += indent
        else:
            cursor -= indent
            print ' ' * cursor, format_end(elem)


if __name__ == '__main__':
    pretty_print(sys.argv[1])