l=['Harvey','Tracy','Sam']t={
   'Harvey','Tracy','Sam'}l.append('Tracy')print(l)scores=[68,76,88]d={
   'Harvey':68,'Tracy':76,'Sam':88}d['Tracy']=99d['Gareth']=111d.pop('Sam')print(d)s1={
   'Harvey','Tracy','Sam'}s2={
   'Harvey','Sam','Gareth'}print(s1&s2)print(s1|s2