def cartcat(s_list1, s_list2):
 prod = itertools.product(s_list1, s_list2)
 return map(partial(apply, operator.add), prod)

def cartcat ( s_list1 , s_list2 ) : prod = itertools . product ( s_list1 , s_list2 ) return map ( partial ( apply , operator . add ) , prod )
given two lists of strings .