hey im making a giveaway command but it throws a error "'async_generator' object has no attribute 'flatten'"

Question

so im making a giveaway command for my bot in discord.py v2 but it throws this error: 'async_generator' object has no attribute 'flatten'

here is an image:

my code -

@client.command(description="Starts a giveaway.")
@has_permissions(manage_messages=True)
async def gcreate(ctx, mins: int, *, prize: str):
    global users, new_msg
    try:
        em = discord.Embed(
            title=f"<a:fun:1052215771738165269> {prize} <a:fun:1052215771738165269>",
            color=discord.Colour.random()
        )
        # end = datetime.datetime.utcnow() + datetime.timedelta(seconds=mins *60)
        timestamp = time.time() + mins
        em.set_footer(text=f"Started by {ctx.author}")
        em.add_field(name=f"** **", value=f"**Ends at**: <t:{int(timestamp)}:f> or <t:{int(timestamp)}:R> \n **Prize**: {prize} \n **Hosted by**: {ctx.author.mention}", inline=False)
        my_msg = await ctx.send(embed=em)
        await my_msg.add_reaction("🎉")
        await asyncio.sleep(mins)
        new_msg = await ctx.channel.fetch_message(my_msg.id)
        users = await new_msg.reactions[0].users().flatten()
        users.pop(users.index(client.user))
        winner = random.choice(users)
        await ctx.send(f'Congratulations {winner.mention} won **{prize}**! Hosted by {ctx.author.mention}')
        em = discord.Embed(
            title=f"Hey! you won **{prize} GG**!",
            description="Join the dev's server https://discord.gg/notsetyet <:",
            color=0xff2424
        )
        em.set_author(name=winner.name, icon_url=winner.avatar_url)
        await winner.send(embed=em)
    except Exception as er:
        await ctx.send(er)

@client.command(description="Rerolls the recent giveaway.")
@has_permissions(manage_messages=True)
async def reroll(ctx, channel: discord.TextChannel, id):
    try:
        new_message = await channel.fetch_message(id)
    except:
        await ctx.send("Incorrect id.")
        return

    users = await new_message.reactions[0].users().flatten()
    users.pop(users.index(client.user))
    winner = random.choice(users)

    reroll_announcement = discord.Embed(color = 0xff2424)
    reroll_announcement.set_author(name = f'The giveaway was re-rolled by the host!', icon_url = 'https://i.imgur.com/DDric14.png')
    reroll_announcement.add_field(name = f'🥳 New Winner:', value = f'{winner.mention}', inline = False)
    await channel.send(embed = reroll_announcement)

i know that flatten has been removed in discord.py v2 but i dont know how to implement the new one im confused any type of help will be appreciated!

Answer 1

The discord.Reaction.users were changed to return an async generator ( PEP 525 ) and have to be turned into a list in your use case. You can easily do it using list comprehension like:

users = [user async for user in reaction.users()]

Instead of:

users = await new_msg.reactions[0].users().flatten()

The example of this can be found in discord.py discord.Reaction.users document.