cost={"苹果":5.2,"山竹":12.9,"香蕉":2.4,"荔枝":15,"葡萄":9.3,"蓝莓":10,"李子":8}
k=input("请输入水果名字:")
v=input("请输入水果价钱:")
if k in cost
    if fioat(v)<cost[k]
    cost[k]=float(v)
    print(k+'降价,现价'+v+'元')
    else:
        print(k+"涨价,我们不卖")
else:
    cost[k] = float(v)
    print(k+"的价钱"+v+"元已经上传")