discord embed freezes on 2nd execution

Question

I have a problem with a slash command, with an embed actually.

When I run the slash command, I get an embed with a button with a label "xN" (where N - any number from 1 to 99). This embed gets edited every 2 seconds, and the button's label and id increase by 1. If I click the button, callback function is called, some logic gets executed in the callback function and the main function stops. And it all works as intended, until 2nd try and all the following. On 2nd try the embed just stops, nothing gets edited and button is not being changed, and when I click the button nothing happens.

Here is the screenshot:

On this screenshot the first /test run worked properly, embed was being edited every two seconds, button's label and id were increasing by 1 and when I clicked the button it edited the embed with "stop function" message from callback function and ended the function (maybe the function wasn't ended tho ??), but when I run it 2nd time, it just freezes at "x1", and when I click it nothing happens.

Here is the code to replicate the problem:

test.py

import asyncio
from discord.ui import Button, View
import discord
from discord.commands import slash_command
from discord.ext import commands
class Test(commands.Cog):
    def __init__(self, bot):
        self.bot = bot
        self.stop_loop = False
    @slash_command(name='test', description='')
    async def run(self, ctx):
        async def button_callback(interaction):
            self.stop_loop = True
            embed = discord.Embed(
            description=f"stop function",
            )
            await interaction.response.edit_message(embed=embed, view=None)
            
            return
        button = Button(custom_id=f"1", label=f'x1', style=discord.ButtonStyle.blurple)
        button.callback = button_callback
        my_view = View()
        my_view.add_item(button)
        embed = discord.Embed(
        title="some title",
        )
        sent_embed = await ctx.respond(embed=embed, view=my_view, ephemeral=True)
        await asyncio.sleep(2)
        for i in range(2, 100):
            if self.stop_loop:
                return
            button = Button(custom_id=f"{i}", label=f'x{i}', style=discord.ButtonStyle.blurple)
            button.callback = button_callback
            my_view = View()
            my_view.add_item(button)
            embed = discord.Embed(
            title="some title",
            )
            await sent_embed.edit_original_response(embed=embed, view=my_view)
            await asyncio.sleep(2)
def setup(bot):
    bot.add_cog(Test(bot))

main.py

from discord.ext import commands
import discord
import os
from tools.config import TOKEN


intents = discord.Intents.default()
intents.members = True
client = commands.Bot(intents=intents, command_prefix = "!")

for f in os.listdir("./cogs"):
    if f.endswith(".py"):
        client.load_extension("cogs." + f[:-3])

client.run(TOKEN)

I am using py-cord==2.4.1 and python3.10 And discord cogs

Answer 1

Your problem happens because you have only one flag self.stop_loop. So, at the second time it is already set to True (after the first execution) and the cycle stops immediately. Also it will be a problem when running that command simultaneously, for example on several guilds.

You need a way to interrupt function run from button_callback event. One of ways to do it is to create custom exception and handle it in outer function:

def A():
    class MyException(Exception):
        ...

    def B():
        # handle event
        raise MyException

    try:
        for i in range(2, 100):
            # bind B to a button click event
            ...
    except MyException:
        return

And corrected code will look like this:

@slash_command(name='test', description='')
async def run(self, ctx):
    class MyException(Exception):
        ...

    async def button_callback(interaction):
        self.stop_loop = True
        embed = discord.Embed(
            description=f"stop function",
        )
        await interaction.response.edit_message(embed=embed, view=None)
        raise MyException

    button = Button(custom_id=f"1", label=f'x1', style=discord.ButtonStyle.blurple)
    button.callback = button_callback
    my_view = View()
    my_view.add_item(button)
    embed = discord.Embed(
        title="some title",
    )
    sent_embed = await ctx.respond(embed=embed, view=my_view, ephemeral=True)
    await asyncio.sleep(2)
    try:
        for i in range(2, 100):
            button = Button(custom_id=f"{i}", label=f'x{i}', style=discord.ButtonStyle.blurple)
            button.callback = button_callback
            my_view = View()
            my_view.add_item(button)
            embed = discord.Embed(
                title="some title",
            )
            await sent_embed.edit_original_response(embed=embed, view=my_view)
            await asyncio.sleep(2)
    except MyException:
        return

Also I'd recommend you to be very carefully with the idea of updating a response every 2 seconds, because this may cause some problems with Discord rate limits.