python - 我收到了 “nonetype”错误，但我不知道为什么

Question

所以我基本上知道错误的含义，但是我不知道为什么得到它。我想将我的cvs文件插入表中。有些行是空的，这就是为什么我使用if None ...的原因。

错误即时消息:

机构中的文件“C:\ Users \ Desktop \ IngestData.py”，第64行
cokey = temp [0]
TypeError:“NoneType”对象不可下标

希望有人能帮助我!
先感谢您!

def institutions(cur):
    with open('persons.csv', 'r', encoding="utf-8") as g:
        #tempo = None
        reader = csv.reader(g)
        next(reader)
        for row in reader:
            if row[4] is None:
                break
            else:
                cur.execute("SELECT COKEY FROM countries WHERE Name = (%s)", [row[4]])
                temp = cur.fetchone()
                cokey = temp[0]
                cur.execute("""INSERT INTO institutions (Name,cokey) VALUES (%s,%s)
                            ON CONFLICT DO NOTHING;""",[row[3],cokey])

Answer 1

您的数据库是否有匹配的行？ cur.fetchone()返回None，这就是为什么您的错误在说NoneType is not suscriptable。

def institutions(cur):
    with open('persons.csv', 'r', encoding="utf-8") as g:
        #tempo = None
        reader = csv.reader(g)
        next(reader)
        for row in reader:
            if row[4] is None:
                break
            else:
                cur.execute("SELECT COKEY FROM countries WHERE Name = (%s)", [row[4]])
                temp = cur.fetchone()
                if temp:
                    cokey = temp[0]
                    cur.execute("""INSERT INTO institutions (Name,cokey) VALUES (%s,%s) ON CONFLICT DO NOTHING;""",[row[3],cokey])