def stable_unique(seq):
 seen = set()
 seen_add = seen.add
 return [x for x in seq if (not ((x in seen) or seen_add(x)))]

def stable_unique ( seq ) : seen = set ( ) seen_add = seen . add return [ x for x in seq if ( not ( ( x in seen ) or seen_add ( x ) ) ) ]
unique a seq and keep its original order .