str_test = 'dddaayyyaannn' print(set(str_test)) #{'a', 'd', 'n', 'y'}
str_unq = ''.join(set(str_test)) print(str_unq) #anyd
from collections import OrderedDict str_odr =''.join(OrderedDict.fromkeys(str_test)) print(str_odf) #dayn