Discord机器人开发：Python中Event loop closed错误及Token加载异常排查

问题场景 #

我在PyCharm中开发Discord机器人，使用的代码如下：

# bot.py
import os

import discord
from dotenv import load_dotenv
load_dotenv()
TOKEN = os.getenv('DISCORD_TOKEN')
GUILD = os.getenv('DISCORD_GUILD')

client = discord.Client()


@client.event
async def on_ready():
    for guild in client.guilds:
        if guild.name == GUILD:
            break
    print(
        f'{client.user} is connected to the following guild:\n'
        f'{guild.name}(id: {guild.id})'
    )


client.run(TOKEN)

运行后出现以下错误：

Traceback (most recent call last):
  File "C:\Users\elrod\venv\lib\site-packages\discord\http.py", line 300, in static_login
    data = await self.request(Route('GET', '/users/@me'))
  File "C:\Users\elrod\venv\lib\site-packages\discord\http.py", line 254, in request
    raise HTTPException(r, data)
discord.errors.HTTPException: 401 Unauthorized (error code: 0): 401: Unauthorized

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\elrod\OneDrive\Desktop\Assignments\CPSC\Python\HextchLibraryApp\HextechLibrary.py", line 25, in <module>
    client.run(TOKEN)
  File "C:\Users\elrod\venv\lib\site-packages\discord\client.py", line 723, in run
    return future.result()
  File "C:\Users\elrod\venv\lib\site-packages\discord\client.py", line 702, in runner
    await self.start(*args, **kwargs)
  File "C:\Users\elrod\venv\lib\site-packages\discord\client.py", line 665, in start
    await self.login(*args, bot=bot)
  File "C:\Users\elrod\venv\lib\site-packages\discord\client.py", line 511, in login
    await self.http.static_login(token.strip(), bot=bot)
  File "C:\Users\elrod\venv\lib\site-packages\discord\http.py", line 304, in static_login
    raise LoginFailure('Improper token has been passed.') from exc
discord.errors.LoginFailure: Improper token has been passed.
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x0000022950CEF160>
Traceback (most recent call last):
  File "C:\Users\elrod\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\elrod\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\elrod\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 751, in call_soon
    self._check_closed()
  File "C:\Users\elrod\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 515, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed

Process finished with exit code 1

已知信息：.env文件中DISCORD_GUILD能正常读取，但DISCORD_TOKEN无法正确加载——直接将token粘贴到client.run()中可正常运行，重置新token也无效。

可能的原因及解决方法 #

• .env文件中Token格式错误
  检查.env内的DISCORD_TOKEN是否存在多余空格、引号或换行符。
  错误示例：DISCORD_TOKEN = "your_token "（末尾带空格）、DISCORD_TOKEN='your_token'（带单引号）
  正确格式：DISCORD_TOKEN=your_token_value（无多余符号，直接键值对）

• load_dotenv()未指定.env文件路径
  如果.env文件不在脚本的同级目录，需要显式指定路径：

  load_dotenv(dotenv_path='./relative/path/to/.env')
  # 或使用绝对路径
  load_dotenv(dotenv_path='C:/Users/elrod/your-project/.env')
  

  可先打印当前工作目录确认路径是否正确：

  print(os.getcwd())
  

• Token包含隐形字符
  复制Token时可能带入隐形字符，在代码中添加打印语句查看加载后的Token：

  print(f"Loaded Token: [{TOKEN}]")
  

  如果输出的方括号内存在额外空格或不可见字符，需清理.env文件内容，手动重新输入Token（避免直接复制粘贴，或粘贴后删除多余字符）

• PyCharm环境变量缓存/覆盖
  重启PyCharm，同时检查Run/Debug配置：

  1. 打开Run > Edit Configurations
  2. 查看当前配置的Environment variables是否手动设置了DISCORD_TOKEN
  3. 若存在手动设置的变量，删除它，让脚本从.env文件读取

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