TypeError：'int'类型的参数不可迭代？这是什么意思？

ClassNames = studentname and score
if studentname not in ClassNames:
   ClassNames = ClassNames.append(studentname)
for studentname in filename and ClassNames <= 3:
    FirstResult.append(score)
    SecondResult.append|(score)
    ThirdResult.append(score)
ClassNames = studentname and score
if studentna