先来看查看效果:

在代码连接数据库后，并且执行三条sql后，将mysql直接重启掉，故我们的连接池连接均是不ok的，所以，它会全部删除再抓新的连接下来，重启mysql命令:

关于python代码:

'''遇到问题没人解答？小编创建了一个Python学习交流QQ群：857662006 寻找有志同道合的小伙伴，互帮互助,群里还有不错的视频学习教程和PDF电子书！'''#!/usr/bin/env python3# -*- coding: UTF-8 -*-import pymysqlimport randomimport time# 初始化mysql 连接池def MySQLInit(mysql_host,mysql_port,mysql_user,mysql_password,mysql_charset,mysql_dbname,mysql_maxconnect): # 定义返回mysql连接池的类型，这里定义为 list return_db_list = [] for Connect in range(0,mysql_maxconnect): try: db = pymysql.connect( host = mysql_host , port = mysql_port , user = mysql_user , passwd = mysql_password , db = mysql_dbname , charset = mysql_charset ) print ("连接MySQL数据库成功，MySQL数据库ID为:%s" %(db)) return_db_list.append(db) except Exception as e: print ("连接MySQL数据库出错") print (e) # 如果mysql连接池为空，则返回-1 if 0 == len(return_db_list): print ("错误 , 连接MySQL数据库失败,连接池为0") return -1 else: # 返回mysql连接池 return return_db_listdef Pull_DB_Connect(mysql_host,mysql_port,mysql_user,mysql_password,mysql_charset,mysql_dbname , MySQL_Connect_Pool , mysql_maxconnect) : # 打印补充前的mysql连接数 print ("补充前MySQL连接数为:",len(MySQL_Connect_Pool)) # 循环相差的连接数 for Connect in range((len(MySQL_Connect_Pool)) , mysql_maxconnect): try: db = pymysql.connect( host = mysql_host , port = mysql_port , user = mysql_user , passwd = mysql_password , db = mysql_dbname , charset = mysql_charset ) print ("重新补充，连接MySQL数据库成功，MySQL数据库ID为:%s" %(db)) # 将刚刚连接成功的DB连接追加到MySQL_Connect_Pool中 MySQL_Connect_Pool.append(db) except Exception as e: print ("重新补充，连接MySQL数据库出错") print (e) if 0 == len(MySQL_Connect_Pool): print ("错误 , 连接MySQL数据库失败,连接池为0") return -1 else: # 打印连接池总数并且返回 print("Mysql 连接池总数为:" , len(MySQL_Connect_Pool)) return MySQL_Connect_Pool def main() : # 定义测试mysql信息 mysql_host = "192.168.1.100" mysql_port = 3306 mysql_user = "liwang" mysql_password = "liwang" mysql_charset = "utf8" mysql_dbname = "itchat" mysql_maxconnect = 3 # 初始化mysql连接池 MySQL_Connect_Pool = MySQLInit(mysql_host,mysql_port,mysql_user,mysql_password,mysql_charset,mysql_dbname,mysql_maxconnect) # 定义初始化sql sql = "show databases;" while True: # 随机获连接池的下标 db_link = random.randint(0,len(MySQL_Connect_Pool)-1) try: # 执行sql cursor = MySQL_Connect_Pool[db_link].cursor() cursor.execute(sql) print (cursor.fetchall()) except Exception as e: # 如果执行失败，模拟为DB连接失效，则打印错误信息，删除错误的MySQL_Connect_Pool信息 print (e) del MySQL_Connect_Pool[db_link] print ("数据库无法连接，删除Mysql连接池下标:" , db_link) # 重新补充mysql连接池 Pull_DB_Connect(mysql_host,mysql_port,mysql_user,mysql_password,mysql_charset,mysql_dbname,MySQL_Connect_Pool,mysql_maxconnect) # 休眠10s time.sleep(10)if __name__ == "__main__" : main()

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。