_sorter(n1,n2) -> int
    Sorting predicate for non-NS attributes.

def _sorter(n1,n2):
    '''_sorter(n1,n2) -> int
    Sorting predicate for non-NS attributes.'''

    i = cmp(n1.namespaceURI, n2.namespaceURI)
    if i: return i
    return cmp(n1.localName, n2.localName)