scores = []
while True:
score = input('请输入分数:')
if score == '':
break
elif not score.isdigit():
print('请输入数字!')
elif int(score) < 0 or int(score) > 100:
print('分数应在 0 到 100 之间!')
else:
scores.append(int(score))
if len(scores) > 0:
print('平均分是:', sum(scores) / len(scores))
else:
print('没有输入分数!')