Discord Bot重复调用时日志双倍/三倍重复的问题排查与解决

问题说明 #

开发了一个简单的Discord Bot，仅用于初始化时向指定频道发送字符串列表作为项目通知模块。功能正常，但重复调用run_discord_bot函数时，控制台日志会出现双倍、三倍的重复输出。尝试用log_handler=None关闭日志会完全移除所有日志，需要解决日志重复的问题。

现有代码 #

import discord
from discord.ext import commands


def run_discord_bot(list_to_print):
    client = commands.Bot(command_prefix='!', intents=discord.Intents.all())

    @client.event
    async def on_ready():
        print("working!")
        channel = client.get_channel(MY CHANNEL ID)
        for item in list_to_print:
            await channel.send(item)
        await client.close()

    client.run("MY TOKEN")


run_discord_bot(["msg1", "msg2"])
run_discord_bot(["msg3", "msg4"])
run_discord_bot(["msg5", "msg6"])

控制台日志示例 #

[2023-06-14 00:50:00] [INFO    ] discord.client: logging in using static token
[2023-06-14 00:50:01] [INFO    ] discord.gateway: Shard ID None has connected to Gateway (Session ID: id1).
working!
[2023-06-14 00:50:04] [INFO    ] discord.client: logging in using static token
[2023-06-14 00:50:04] [INFO    ] discord.client: logging in using static token
[2023-06-14 00:50:05] [INFO    ] discord.gateway: Shard ID None has connected to Gateway (Session ID: id2).
[2023-06-14 00:50:05] [INFO    ] discord.gateway: Shard ID None has connected to Gateway (Session ID: id2).
working!
[2023-06-14 00:50:07] [INFO    ] discord.client: logging in using static token
[2023-06-14 00:50:07] [INFO    ] discord.client: logging in using static token
[2023-06-14 00:50:07] [INFO    ] discord.client: logging in using static token
[2023-06-14 00:50:08] [INFO    ] discord.gateway: Shard ID None has connected to Gateway (Session ID: id3).
[2023-06-14 00:50:08] [INFO    ] discord.gateway: Shard ID None has connected to Gateway (Session ID: id3).
[2023-06-14 00:50:08] [INFO    ] discord.gateway: Shard ID None has connected to Gateway (Session ID: id3).
working!

Process finished with exit code 0

问题原因 #

discord.py的日志系统是全局共享的，每次调用run_discord_bot创建新的commands.Bot实例时，client.run()方法会自动为discord命名空间的日志器添加一个StreamHandler（控制台输出处理器）。多次调用后，日志器会累积多个相同的处理器，每条日志会被所有处理器分别输出一次，导致日志重复次数与函数调用次数一致。

解决方法 #

方法1：重构代码，复用单个Bot实例（推荐） #

反复创建Bot实例并登录登出不仅会导致日志重复，还可能触发Discord API的频率限制。最优方案是只初始化一次Bot，复用它完成所有消息发送任务：

import discord
from discord.ext import commands
import asyncio

# 替换为你的频道ID和Bot令牌
MY_CHANNEL_ID = 123456789012345678
MY_TOKEN = "your_bot_token_here"

async def send_notifications(client, message_list):
    # 等待Bot完成初始化连接
    await client.wait_until_ready()
    channel = client.get_channel(MY_CHANNEL_ID)
    if channel:
        for msg in message_list:
            await channel.send(msg)

async def main():
    # 仅初始化一次Bot实例
    intents = discord.Intents.all()
    client = commands.Bot(command_prefix='!', intents=intents)
    
    async with client:
        # 批量发送消息
        await send_notifications(client, ["msg1", "msg2"])
        await send_notifications(client, ["msg3", "msg4"])
        await send_notifications(client, ["msg5", "msg6"])
        # 发送完成后关闭连接
        await client.close()

if __name__ == "__main__":
    asyncio.run(main())

方法2：清理重复的日志处理器（兼容原有调用逻辑） #

如果必须保留多次调用run_discord_bot的逻辑，可以在每次创建Bot实例前，清理discord日志器中已存在的处理器：

import discord
from discord.ext import commands
import logging

# 替换为你的频道ID和Bot令牌
MY_CHANNEL_ID = 123456789012345678
MY_TOKEN = "your_bot_token_here"

def run_discord_bot(list_to_print):
    # 清理discord日志器的重复处理器
    discord_logger = logging.getLogger('discord')
    while discord_logger.handlers:
        discord_logger.removeHandler(discord_logger.handlers[0])
    
    client = commands.Bot(command_prefix='!', intents=discord.Intents.all())

    @client.event
    async def on_ready():
        print("working!")
        channel = client.get_channel(MY_CHANNEL_ID)
        for item in list_to_print:
            await channel.send(item)
        await client.close()

    client.run(MY_TOKEN)

# 保留原有调用逻辑
run_discord_bot(["msg1", "msg2"])
run_discord_bot(["msg3", "msg4"])
run_discord_bot(["msg5", "msg6"])

内容的提问来源于stack exchange，提问作者Jakub222444