python - 如何在循环中打印列表中的不同值？

Question

我正在尝试制作一个 Discord 机器人，我想添加的功能之一是从列表中随机选择一个项目并将其发布。一段时间后，从同一列表中选择一个新项目并发布。

Discord.py github 有一个执行循环/后台任务的示例。

import discord
import asyncio

client = discord.Client()

async def my_background_task():
    await client.wait_until_ready()
    counter = 0
    channel = discord.Object(id='channel_id_here')
    while not client.is_closed:
        counter += 1
        await client.send_message(channel, counter)
        await asyncio.sleep(60) # task runs every 60 seconds

@client.event
async def on_ready():
    print('Logged in as')
    print(client.user.name)
    print(client.user.id)
    print('------')

client.loop.create_task(my_background_task())
client.run('token')

上面的代码工作正常。机器人登录并不断计数。以下是我尝试改变它的方法。

import discord
import asyncio
import random

client = discord.Client()

async def my_background_task():
    await client.wait_until_ready()
    postimage = random.choice(list(open('imgdb.txt'))) #Opens my list of urls and then pick one from there.
    channel = discord.Object(id='channel_id_here')
    while not client.is_closed:
     await client.send_message(channel, postimage)
     await asyncio.sleep(10) # task runs every 10 seconds for testing

@client.event
async def on_ready():
    print('Logged in as')
    print(client.user.name)
    print(client.user.id)
    print('------')

client.loop.create_task(my_background_task())
client.run('token')

问题是，机器人会随机选择一张图像，然后继续一遍又一遍地发布相同的图像。如何强制每个循环的帖子图像都不同？

Answer 1

每次发送之前，您必须更改postimage的值。

async def my_background_task():
    await client.wait_until_ready()
    channel = discord.Object(id='channel_id_here')
    while not client.is_closed:
        postimage = random.choice(list(open('imgdb.txt'))) # Open my list of urls and then pick one from there.
        await client.send_message(channel, postimage)
        await asyncio.sleep(10) # Run every 10 seconds for testing