Python 3.x Discord.py Python经济机器人与mongodb“；“非类型”；错误

（糟糕的英语） 我想用mongodb创建一个经济型机器人，它在两天前运行良好，但现在我出现了“非类型”错误

main.py中的Sorce代码（用于在数据库中添加用户）：

这段代码正在运行，因为我在db上看到了这一点

cog的源代码有问题：

class Economic(commands.Cog):
    def __init__(self, client):
        self.client = client
        self.cluster  = MongoClient(f"mongodb+srv://discord:{secret}@cluster403.xn9cm.mongodb.net/discord1?retryWrites=true&w=majority")
        cluster  = MongoClient(f"mongodb+srv://discord:{secret}@cluster403.xn9cm.mongodb.net/users?retryWrites=true&w=majority")
        self.collection = cluster.users.tutu
    @commands.command(
        name = "balance",
        aliases = ["ball","money"],
        brief = "User balance",
        usage = "balance <@user>",
        description = "none....."
    )
    async def user_balace(self, ctx, member: discord.Member = None):
        if member is None:
            embed = discord.Embed(
                title = f"__{ctx.author}__'s balance",
                description = f"Money: {self.collection.find_one({'_id': ctx.author.id})['balance']}"
            )
            await ctx.send(embed=embed)

---

有人能帮我吗？（抱歉我的英语不好）

错误消息实质上是说

self.collection.find\u one（{u id:ctx.author.id}）

返回为

None

。在中，我们可以看到

find_one（）

将在集合中找不到此类项目时返回

None

。我会重新编写您的代码，以便在数据库中没有特定用户的情况下具有安全性

if self.collection.find({'_id': ctx.author.id}).count() == 0:
    self.collection.insert_one({USER OBJECT})

user = self.collection.find_one({'_id': ctx.author.id})

Ignoring exception in command balance:
Traceback (most recent call last):
  File "D:\lib\site-packages\discord\ext\commands\core.py", line 85, in wrapped
    ret = await coro(*args, **kwargs)
  File "C:\Users\Nick403\Desktop\Apps\PROJECTS\BOT\cogs\eco.py", line 22, in user_balace
    description = f"Money: {self.collection.find_one({'_id': ctx.author.id})['balance']}"
TypeError: 'NoneType' object is not subscriptable

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

Traceback (most recent call last):
  File "D:\lib\site-packages\discord\ext\commands\bot.py", line 939, in invoke
    await ctx.command.invoke(ctx)
  File "D:\lib\site-packages\discord\ext\commands\core.py", line 863, in invoke
    await injected(*ctx.args, **ctx.kwargs)
  File "D:\lib\site-packages\discord\ext\commands\core.py", line 94, in wrapped
    raise CommandInvokeError(exc) from exc
discord.ext.commands.errors.CommandInvokeError: Command raised an exception: TypeError: 'NoneType' object is not subscriptable

if self.collection.find({'_id': ctx.author.id}).count() == 0:
    self.collection.insert_one({USER OBJECT})

user = self.collection.find_one({'_id': ctx.author.id})