我试图在我的查询中清除 'null'，但是运行它时仍然出错，一直告诉我 'cannot cast'' to bigint，有什么办法可以解决它？
我的查询
select m.app, m.hour,m.user_id,
m.avg_minutes_watched, n.userid, n.watched_mins, n.active FROM
(SELECT app,
substr(hour,1,8) hour,
CAST(COALESCE(json_extract_scalar(json, '$.user_id'), '-999999') as BigInt) user_id,
CAST(COALESCE(json_extract_scalar(json, '$.playback_time'), '-999999') as BigInt) /60000 avg_minutes_watched
FROM prod
WHERE event_type = 'user_session_complete' AND hour > '20180331' and hour < '20180501')m
left join
(select userid, watched/60000 watched_mins,
(case when watched/60000 >= 2 then 'active' else 'not_active' end) active from est where realdate > '2018-03-31' and realdate < '2018-05-01') n
on m.user_id = n.userid
order by …所以在这里我试图将字符串' ABcsad f!,'转换为
string 'abcsadf'，所以基本上我正在尝试将空格和非alpha替换为''，但是我的代码根本不起作用...
s = ' ABcsad f!,'
def norm(s):
b=''
i=0
for i in range(0,len(s)+1):
if (s[i].isalpha() is False) or (s[i].isspace() is False) :
return b+=''
else:
return b+=s[i]
i = i+1
print(norm(s))
谁能告诉我我哪里出了问题？
因此，这是一个名为grade_lists的表，该表将学生的姓名映射到他们的考试成绩列表。等级应从字符串转换为整数。例如，grade_lists ['Thorny'] == [100，90，80]。有人能帮我吗？
grades = [ #here is the table
['Student', 'Exam 1', 'Exam 2', 'Exam 3'],
['Thorny', '100', '90', '80'],
['Mac', '88', '99', '111'],
['Farva', '45', '56', '67'],
['Rabbit', '59', '61', '67'],
['Ursula', '73', '79', '83'],
['Foster', '89', '97', '101']
]