controller.py

import pymysql


class TaskServer:
    def __int__(self):
        self.client = pymysql.connect("xxxxx")

    def query_task(self):
        cursor = self.client.cursor(cursor=pymysql.cursors.DictCursor)
        sql = "select id from table where status = 0"
        cursor.execute(sql)
        res = cursor.fetchall()
        cursor.close()
        return res

    def update_runnig_task(self, task_id):
        cursor = self.client.cursor(cursor=pymysql.cursors.DictCursor)
        sql = "update table set status=1 where id = {}".format(task_id)
        cursor.execute(sql)
        self.client.commit()
        cursor.close()

    def get_task(self, task_id):
        cursor = self.client.cursor(cursor=pymysql.cursors.DictCursor)
        sql = "select * from table where id = {}".format(task_id)
        cursor.execute(sql)
        res = cursor.fetchone()
        cursor.close()
        return res

    def save_result(self, task, result):
        cursor = self.client.cursor(cursor=pymysql.cursors.DictCursor)
        update_task_sql = "update table set status={}".format(task["status"])
        
        insert_result_sql = "xxxxxxxxxx"
        cursor.execute(update_task_sql)
        cursor.execute(insert_result_sql)
        self.client.commit()
        cursor.close()
        
    def close(self):
        if self.client:
            self.client.close()
            self.client = None

logic.py

from controller import TaskServer

class Logic:
    def __init__(self, id):
        self.id = id
        self.taskServer = TaskServer()
        self.task = self.taskServer.get_task(self.id)

    def run(self):
        """
        0代表未执行, 1正在执行, 2代表执行失败, 3代表执行成功
        :return:
        """
        self.taskServer.update_runnig_task(self.id)
        self.task["status"] = 1
        try:
            """
            res = do task
            """
            res = "function do task"
            if "成功" in res.get("content"):
                self.task["status"] = 3
            else:
                self.task["status"] = 2

            self.taskServer.save_result(self.task, res)

        except:
            self.task["status"] = 2
            res = "fuction make error result"
            self.taskServer.save_result(self.task, res)
        finally:
            if self.task["status"] in (0, 1):
                res = "function make error result"
                self.task["status"] = 2
                self.taskServer.save_result(self.task, res)

    def __del__(self):
        if self.taskServer:
            self.taskServer.close()
        self.taskServer = None

main.py

from controller import TaskServer
from threading import Thread
from queue imoprt Queue
from logic import Logic
import time

q = Queue(3)

def create_task():
  global q
  while 1:
    db_driver = TaskServer()
    task = db_driver.query_task()
    if task:
      q.put(task[0])
    db_driver.close()
    db_driver = None
    time.sleep(5)


def execute_task():
  global q
  while 1:
    task = q.get()
    driver = Logic(task)
    driver.run()
    driver = None
    

Thread(target=create_task).start()
Thread(target=execute_task).start()
Thread(target=execute_task).start()
Thread(target=execute_task).start()