Python列表相关题

有一题Python不会做，请问可以帮我看一下吗？

天气列表如下，可以直接复制到程序中。
lst_weather=[["周一", "16℃", "26℃","多云","1级","优"],
[ "周二" ,"17℃", "27℃","晴","2级","优"],
[ "周三","16℃", "28℃","晴","3级","优"],
[ "周四","16℃", "25℃","阴","2级","良"],
[ "周五","15℃", "24℃","阴","2级","良"],
[ "周六", "15℃", "25℃","晴","3级","优"],
[ "周日","14℃", "23℃","小雨","3级","良"]]

lst_weather=[["周一", "16℃", "26℃","多云","1级","优"],
[ "周二" ,"17℃", "27℃","晴","2级","优"],
[ "周三","16℃", "28℃","晴","3级","优"],
[ "周四","16℃", "25℃","阴","2级","良"],
[ "周五","15℃", "24℃","阴","2级","良"],
[ "周六", "15℃", "25℃","晴","3级","优"],
[ "周日","14℃", "23℃","小雨","3级","良"]]

lst1 = [x[0] for x in lst_weather if x[5] == "优"]
print(f"空气质量为优的天数: {len(lst1)}, 它们分别是:",", ".join(lst1))

lst2 = [x[0] for x in lst_weather if x[4][0] < "3" and int(x[2][:2]) <= 25]
print(f"风力低于3级且最高气温不超过25℃的天数: {len(lst2)}, 它们分别是:",", ".join(lst2))

lst3 = [x[0] for x in lst_weather if (int(x[2][:2])+int(x[1][:2]))/2<20]
print(f"平均气温低于20℃的天数: {len(lst2)}, 它们分别是:",", ".join(lst3))

res_l = [x for x in lst_weather if x[5] == '优']
res = [x[0] for x in res_l]
print("空气质量为优的天数：{},它们分别是:{}".format(len(res), ','.join(res)))

res_l = [x for x in lst_weather if int(x[2][0:2]) <= 25 and int(x[4][0]) < 3]
res = [x[0] for x in res_l]
print("风力低于三级且最高温度不超过25℃的天数：{},它们分别是：{}".format(len(res), ','.join(res)))

res_l = [x for x in lst_weather if (int(x[2][0:2])+int(x[1][0:2]))/2 < 20.0]
res = [x[0] for x in res_l]
print("平均气温低于20℃的天数：{},它们分别是：{}".format(len(res), ','.join(res)))