The producer group has been created before, specify another name please.

I am using rocketmq in the flash application.
But when the application wants to send a message the second time, it meets this exeception
**The producer group has been created before, specify another name please.**

Here is my code:
`
from rocketmq.client import Producer, Message
import json
import uuid
from config import Config

def send_message(message):
'''
发送消息队列
:param message: 消息体，必须是字典或json格式
:return:
'''
group = Config.getConfig().MSG_GROUP
# group = str(uuid.uuid4())
topic = Config.getConfig().MSG_GROUP
addr = Config.getConfig().MSG_ADDR
producer = Producer(group)

producer.set_namesrv_addr(addr) # rocketmq队列接口地址（服务器ip:port）
producer.start()

msg = Message(topic)
msg.set_tags('python_compare_tag')
msg.set_body(str(json.dumps(message)))

producer.send_sync(msg)
producer.shutdown()
`

Question:
1. Does the app need to create a new group every time?
2. If not, how should I change the code to solve this execption?
3. Does rocketmq has some framework with flask app?