def unicode_sorter(input):
 key1 = input.lower()
 key1 = key1.replace(u'\xe4', u'a')
 key1 = key1.replace(u'\xf6', u'o')
 key1 = key1.replace(u'\xfc', u'u')
 key1 = key1.replace(u'\xdf', u'ss')
 return key1

def unicode_sorter ( input ) : key1 = input . lower ( ) key1 = key1 . replace ( u'\xe4' , u'a' ) key1 = key1 . replace ( u'\xf6' , u'o' ) key1 = key1 . replace ( u'\xfc' , u'u' ) key1 = key1 . replace ( u'\xdf' , u'ss' ) return key1
this function implements sort keys for the german language according to din 5007 .