我看了你样例,大约是9折把 501*0.9=450.9
# coding:UTF-8
consume = float(input("请输入消费金额(元):"))
if consume <= 500:
print "实际支付金额为:" + str(consume)
else:
if consume * 0.1 > 100:
print "实际支付金额为:" + str(consume-100)
else:
print "实际支付金额为:" + str(consume*0.9)