python3.7-初学篇-13
score = int (input ('请教您的分数:'))
if 100 >= score >= 90:
print ('A')
else:
if 90 > score >= 80:
print ('B')
else:
if 80 > score >= 60:
print ('C')
else:
if 60 > score >= 0:
print ('D')
else:
print ('输入错误!')