0-- print A/B/C/D rather than detail score:
score = float(input('please input your score: '))
if score>=90:
print('A')
elif 80<=score<90:
print('B')
elif 60<=score<80:
print('C')
else:
print('D')
1-- compare
small = x if (x < y and x < z) else (y if y < z else z)