How to make bot react to users' mentions?

[Martyn0324]

I want to make a minigame using my Discordpy bot. The idea is:

1. User starts minigame with a command;
2. Bot confirms that the minigame have been started;
3. Bot asks for a 2nd player to play the minigame;
4. User mentions 2nd player with mention(@user in discord);
5. Minigame starts.

My only problem in this case is the 4th stage: I can't make my bot detect mentions when the user answers its question.

I've tried 2 different codes based on what I found at the internet:

First Code:

@client.command()
async def duel1(ctx):
    await ctx.send("Cráááá! {0.author.mention}, so you desire to wash your honor in blood and pleasure yourself with revenge's sweet taste? Cráááá! Very well...".format(ctx))
    await ctx.send('https://media1.tenor.com/images/ce1b9df56301c8443bcb4b5edbbfbdf7/tenor.gif?itemid=4581114')
    await ctx.send("Then select your opponent! Cráááá!")
    #From this point, the bot won't do anything more.
    #The following is the code used to make the bot react to a message that contains a mention.
    async def opponent(msg, member: discord.Member=None):
        if not member:
            await msg.send('Cráááááá! You need to ping your enemy! Are you scared? Cráááá!')
            return
        if member:
            await msg.message.channel.send("Cráááá! {0.member.mention}, you have been challenged by {0.author.mention} to a duel! As the challenged one, you can be the first to choose the weapon that you're gonna use during this duel. Crááá!".format(msg))

Second Code:

@client.command()
async def duel2(ctx):
    await ctx.send("Cráááá! {0.author.mention}, so you desire to wash your honor in blood and pleasure yourself with revenge's sweet taste? Cráááá! Very well...".format(ctx))
    await ctx.send('https://media1.tenor.com/images/ce1b9df56301c8443bcb4b5edbbfbdf7/tenor.gif?itemid=4581114')
    await ctx.send("Then select your oponent! Cráááá!")
    def check(message):
        return message.author == ctx.author and message.content == str(discord.mentions)
    msg = await client.wait_for('message', timeout=20, check = check)
    if asyncio.TimeoutError and msg is None:
        await ctx.send("Cráááááá! What's the problem? Are you scared? Crááá! Call me when you stop crying out of fear! Cráááá!")
    elif msg:
        await ctx.send("Cráááá! {0.user.mention} you have been defied by {0.author.mention} to a duel! As the challenged one, you can be the first to choose the weapon that you're gonna use during this duel. Crááá!".format(ctx))

I've managed to make the TimeoutError work. However, as I've tried to correct the code, I messed up with it and now not even the Timeout is working. The situation is the same as the first code: after await ctx.send("Then select your opponent! Cráááá!") , the bot won't say nor react to anything.

PS: I do not want to use users IDs or databases in order to make the bot detect mentions.

Links I've checked:
https://discordpy.readthedocs.io/en/latest/api.html?highlight=wait_for#discord.Client.wait_for
https://discordpy.readthedocs.io/en/latest/api.html?highlight=user%20mention#discord.ClientUser.mention
https://discordpy.readthedocs.io/en/latest/api.html?highlight=discord%20mentions#discord.Message.raw_mentions
https://github.com/Rapptz/discord.py/blob/async/examples/reply.py#L12

[Rapptz]

Your second code is closer to what you want to do, however the check function is wrong. There is no such thing as discord.mentions and taking the str out of it makes little sense.

Messages have a Message.mentions attribute that allow you to get the members being mentioned in the message. So a simple way of doing it is just checking if they mentioned one person like so:

def check(message):
    return message.author == ctx.author and len(message.mentions) == 1 and message.mentions[0] != ctx.author

This check predicate checks whether there was a mention and also makes sure that the person mentioned isn't the person using the command.

There is another issue in your second code and that's the handling of your TimeoutError, in Python this is a raised exception that must be caught to be handled, so we do something like this as seen in the documentation.

try:
    msg = await client.wait_for('message', timeout=20, check=check)
except asyncio.TimeoutError:
    return await ctx.send("Cráááááá! What's the problem? Are you scared? Crááá! Call me when you stop crying out of fear! Cráááá!")
else:
    # In here, we didn't time out and msg is a valid discord.Message object
    opponent = msg.mentions[0]

Notice that I call return in the except clause so the function finishes when there is no valid opponent given.

After putting all this together you should have both a working program and an opponent variable pointing to the person you're playing against.

[Martyn0324]

Thanks, it worked! Just one more thing, though: I've seen that if I add message.mentions[0] != client.user to the check variable, the bot won't accept itself as a possible opponent. Is there a way to apply this filter to any other bots in a guild?
Also, I noticed that if I want to make the 2nd player choose an option, I can use the opponent variable. If I want to make the 1st player to choose right after that, should I still use {ctx.author} ?

[Rapptz]

Bots can be detected via User.bot. So in this case message.author.bot checks if the user is a bot.

You are correct that the original author is still ctx.author.