Discord.py开发经济Cog时出现Economy对象无ctx属性报错如何解决

错误根因 #

「Economy object doesn't have an attribute ctx」报错的直接原因是代码错误使用了self.ctx.author.id，self指向的是Economy Cog类的实例，该实例本身没有预存ctx属性，ctx是当前_bet命令函数的入参，直接调用即可，不需要加self.前缀。

额外问题修复 #

代码中还有多个影响功能运行的问题需要同步处理：

• 重复嵌套打开了两次data/eco.json只读流，属于无用冗余代码
• 没有校验调用命令的用户是否已经在eco.json中初始化经济数据，直接修改会抛出KeyError
• 没有校验下注金额合法性（负数、用户余额不足的情况）
• 写入json无缩进，后续排查数据可读性差

修正后的完整代码 #

@commands.command(name="bet", aliases=["be", "b"], brief="You bet for honeycomb", description="If you lose you give honeycomb, if you win you get honeycomb")
async def _bet(self, ctx, amount : int = 5):
    # 下注金额合法性校验
    if amount < 1:
        embed = discord.Embed(title="下注错误", description="下注金额不能小于1", color=0xff0000)
        await ctx.send(embed=embed)
        return
    user_id = str(ctx.author.id)
    # 读取经济数据
    with open("data/eco.json", "r") as dataRead:
        dataReadJSON = json.load(dataRead)
    # 初始化未注册用户的经济数据
    if user_id not in dataReadJSON:
        dataReadJSON[user_id] = 0 # 可替换为你设定的初始余额
    # 余额充足性校验
    if dataReadJSON[user_id] < amount:
        embed = discord.Embed(title="下注错误", description="你的蜂巢余额不足", color=0xff0000)
        await ctx.send(embed=embed)
        return
    # 胜负随机判定
    cance = [True, False]
    random_chance = random.choice(cance)
    if random_chance:
        dataReadJSON[user_id] += int(amount*2)
        embed = discord.Embed(title="Bet", description=f"You bet and won <:honeycomb0:879275123486633984>{amount*2}", color=0xffff00)
    else:
        dataReadJSON[user_id] -= int(amount)
        embed = discord.Embed(title="Bet", description=f"You bet and lost <:honeycomb0:879275123486633984>{amount}", color=0xff0000)
    # 写入更新后的数据
    with open("data/eco.json", "w") as dataWrite:
        json.dump(dataReadJSON, dataWrite, indent=4)
    await ctx.send(embed=embed)

内容的提问来源于stack exchange，提问作者AidanGamin