在while循环里输入考试成绩,并用if语句进行等级评定
while True:
score = int(input("score:"))
if score > 100 or score < 0:
print ("请重新输入")
elif score >= 90:
print ("A")
elif score >= 80:
print ("B")
elif score >= 70:
print ("C")
elif score >= 60:
print ("D")
else:
print ("垃圾")