在python中已存在的csv文件的新列中写入

Question

我试图在存在数据的csv文件的第三列中写入for循环的输出，但是每次尝试我的代码时，现有数据都会被新数据替换。

这是我尝试过的

  SELECT orders.user_id
    , orders.order_id
    , members.name
    , members.family
    , orders.agent_id
    , CONCAT(m.name, ' ', m.family) AS agent_name 
    INTO OUTFILE 'weekly_orders.csv' FIELDS TERMINATED BY ','
    FROM orders 
    JOIN members ON members.username=orders.user_id 
    join members m on orders.agent_id=m.username 
    where order_status=4 
    and pay_method='verbalPayment' 
    and agent_id is not NULL and order_time between 1559935800 and 1560596861 

import pandas as pd
primes = [2, 3, 5, 7]
for prime in primes:
  df = pd.DataFrame({'name': primes})
  df.to_csv (r'file.csv', index = None, header=True) # here you have to write path, where result file will be stored
print (df)

这是结果，而应该像

name
0     2
1     3
2     5
3     7