Discord Bot报错：期望token为str却收到NoneType的解决求助

问题说明 #

编写Discord Bot时触发TypeError，提示token应为字符串但收到NoneType。已尝试用dotenv加载token.env文件，但问题未解决，打印os.getenv('TOKEN') is None返回True，说明环境变量未正确加载。

代码 #

import discord
import os
from dotenv import load_dotenv

load_dotenv('token.env')

from discord.ext import commands

intents = discord.Intents.default()
intents.message_content = True

bot = commands.Bot(command_prefix='$', intents=intents, help_command=None)

client = discord.Client(intents=discord.Intents.default())

@client.event
async def on_ready():
    print('We have logged in as {0.user}'.format(client))

@client.event
async def on_message(message):
    if message.author == client.user:
        return

    if message.content.startswith('$hello'):
        await message.channel.send('Hello!')

print(os.getenv('TOKEN') is None)
client.run(os.getenv('TOKEN'))

运行报错 #

True
2022-08-18 08:59:59 INFO     discord.client logging in using static token
Traceback (most recent call last):
  File "main.py", line 26, in <module>
    client.run(os.getenv('TOKEN'))
  File "/home/runner/MyLibrary/venv/lib/python3.8/site-packages/discord/client.py", line 828, in run
    asyncio.run(runner())
  File "/nix/store/2vm88xw7513h9pyjyafw32cps51b0ia1-python3-3.8.12/lib/python3.8/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/nix/store/2vm88xw7513h9pyjyafw32cps51b0ia1-python3-3.8.12/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete
    return future.result()
  File "/home/runner/MyLibrary/venv/lib/python3.8/site-packages/discord/client.py", line 817, in runner
    await self.start(token, reconnect=reconnect)
  File "/home/runner/MyLibrary/venv/lib/python3.8/site-packages/discord/client.py", line 745, in start
    await self.login(token)
  File "/home/runner/MyLibrary/venv/lib/python3.8/site-packages/discord/client.py", line 577, in login
    raise TypeError(f'expected token to be a str, received {token.__class__!r} instead')
TypeError: expected token to be a str, received <class 'NoneType'> instead

解决步骤 #

• 检查token.env文件的正确性

  • 确保文件和main.py在同一目录下
  • 文件内容格式为TOKEN=你的机器人令牌，不要给令牌加引号，等号前后不要留空格

• 确认load_dotenv的加载逻辑

  • 若文件路径无误仍加载失败，可打印当前目录确认路径：print(os.getcwd())
  • 建议将文件名改为.env，然后直接调用load_dotenv()（无参数），dotenv会自动搜索当前目录下的.env文件，更符合规范

• 验证环境变量加载状态

  • 打印所有环境变量排查：print(os.environ)，确认TOKEN是否存在
  • 通过load_dotenv的返回值判断加载是否成功：

    if not load_dotenv('token.env'):
        print("加载环境变量文件失败")
    

• 清理冗余代码

  • 代码中同时创建了commands.Bot和discord.Client两个实例，这是冗余的，只需保留一个。比如改用Bot实例，调整事件装饰器并使用bot.run()：

    # 移除client相关代码，保留bot实例
    @bot.event
    async def on_ready():
        print('We have logged in as {0.user}'.format(bot))
    
    @bot.event
    async def on_message(message):
        if message.author == bot.user:
            return
        await bot.process_commands(message)  # 必须加这行才能让命令正常工作
        if message.content.startswith('$hello'):
            await message.channel.send('Hello!')
    
    bot.run(os.getenv('TOKEN'))
    

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