python 链接mysql 连接池

# python 链接mysql
import  mysql.connector.pooling
config = {
    "host":"localhost",
    "port": 3306,
    "user" : "root",
    "password" : "",
    "database" : "demo"
}

try:
    pool = mysql.connector.pooling.MySQLConnectionPool(
        **config,
         pool_size = 10
      )
    con = pool.get_connection()
    con.start_transaction()
    cursor = con.cursor()
    sql = "UPDATE t_emp set sal = sal + %s where deptno = %s"
    cursor.execute(sql,(200, 20))
    con.commit()
except Exception as e:
    if 'con' in dir():
        con.rollback
    print(e)