This compare function works for me:
def elements_equal(e1, e2):
if e1.tag != e2.tag: return False
if e1.text != e2.text: return False
if e1.tail != e2.tail: return False
if e1.attrib != e2.attrib: return False
if len(e1) != len(e2): return False
return all(elements_equal(c1, c2) for c1, c2 in zip(e1, e2))