Python discord.py如何为用户每次try 农场XP时添加冷却时间(调平系统，在消息事件上)

我正在研发一个调平机器人.我发现了获得XP的一个主要问题，它很容易被滥用.我想让它在用户发送消息后有一个冷却时间，这样当用户在一个渠道向XP农场发送垃圾邮件时，他们对每条消息有0.5秒的冷却时间，以防止垃圾邮件.如果你发了很多垃圾短信，你很容易就能登上榜首，我不希望这种情况发生.每件事都与它一起工作，XPyield ，排行榜，以及升级消息.我在互联网上寻找了这个问题的答案，但没有一个起到帮助作用.有人知道吗？请多多关照！:)

代码:

@bot.event
async def on_message(message):
    if not message.author.bot:
        # specify the encoding as utf-8 when opening the file
        with open('level.json','r', encoding='utf-8') as f:
            users = json.load(f)
        await update_data(users, message.author,message.guild)
        await add_experience(users, message.author, 4, message.guild)
        await level_up(users, message.author,message.channel, message.guild)

        # specify the encoding as utf-8 when writing the file
        with open('level.json','w', encoding='utf-8') as f:
            json.dump(users, f)
    await bot.process_commands(message)




async def update_data(users, user,server):
    if not str(server.id) in users:
        users[str(server.id)] = {}
        if not str(user.id) in users[str(server.id)]:
            users[str(server.id)][str(user.id)] = {}
            users[str(server.id)][str(user.id)]['experience'] = 0
            users[str(server.id)][str(user.id)]['level'] = 1
    elif not str(user.id) in users[str(server.id)]:
            users[str(server.id)][str(user.id)] = {}
            users[str(server.id)][str(user.id)]['experience'] = 0
            users[str(server.id)][str(user.id)]['level'] = 1

async def add_experience(users, user, exp, server):
  users[str(user.guild.id)][str(user.id)]['experience'] += exp

async def level_up(users, user, channel, server):
  experience = users[str(user.guild.id)][str(user.id)]['experience']
  lvl_start = users[str(user.guild.id)][str(user.id)]['level']
  lvl_end = int(experience ** (1/4))
  if str(user.guild.id) != '757383943116030074':
    if lvl_start < lvl_end:
      await channel.send(':fire: {} has leveled up to **Level {}!**'.format(user.mention, lvl_end))
      users[str(user.guild.id)][str(user.id)]['level'] = lvl_end
      embed=discord.Embed(title=':fire: {} has leveled up to **Level {}!**'.format(user.mention, lvl_end), color=0x38ff6a)
      await bot.get_channel(log_channel_id).send(embed=embed)

@bot.command(aliases = ['rank','lvl'])
async def level(ctx,member: discord.Member = None):
    if not member:
        user = ctx.message.author
        # specify the encoding as utf-8 when opening the file
        with open('level.json','r', encoding='utf-8') as f:
            users = json.load(f)
        lvl = users[str(ctx.guild.id)][str(user.id)]['level']
        exp = users[str(ctx.guild.id)][str(user.id)]['experience']

        embed = discord.Embed(title = 'Level {}'.format(lvl), description = f"{exp} XP " ,color = discord.Color.green())
        embed.set_author(name = ctx.author, icon_url = ctx.author.avatar.url)
        await ctx.send(embed = embed)
    else:
      # specify the encoding as utf-8 when opening the file
      with open('level.json','r', encoding='utf-8') as f:
          users = json.load(f)
      lvl = users[str(ctx.guild.id)][str(member.id)]['level']
      exp = users[str(ctx.guild.id)][str(member.id)]['experience']
      embed = discord.Embed(title = 'Level {}'.format(lvl), description = f"{exp} XP" ,color = discord.Color.green())
      embed.set_author(name = member, icon_url = member.avatar.url)

      await ctx.send(embed = embed)

JSON文件示例:

{
  "757383943116030074": {
    "123456789012345678": {
      "experience": 0,
      "level": 1
    }
  }
}