Im getting the "nonetype" error but i cant figure out why

Question

so i basically know what the Error means but i don't know why i'm getting it.I want to insert my cvs file into a table. Some of the rows are empty, thats why im using the if None...

The Error im getting:

File "C:\Users\Desktop\IngestData.py", line 64, in institutions cokey = temp[0] TypeError: 'NoneType' object is not subscriptable

Hope somebody can help me! Thank you in advance!

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

Does your database have any matching rows? cur.fetchone() is returning None, that's why your error is saying that 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])