Permission System for Discord.py Bot

Question

I am in the process of making a discord bot using discord.py and asyncio. The bot has commands like kick and ban which obviously should not be available to normal users.

I want to make a simple system which will detect what permissions the user's role has using ctx.message.author to get the user who sent the command.

I do not want the bot to detect a specific role name as these vary across servers. I also prefer not to have multiple files for the bot to keep it simple.

I have seen the discord.py documentation and various other sources but none contain examples of how to implement the various methods they talk about.

As an example, here is a single command from my bot:

async def kick(ctx, userName: discord.User):
    if True: #ctx.message.author.Permissions.administrator
        await BSL.kick(userName)
    else:
        permission_error = str('Sorry ' + ctx.message.author + ' you do not have permissions to do that!')
        await BSL.send_message(ctx.message.channel, permission_error)

Where the if else statement is my attempt of doing this on my own. The #ctx.message.author.Permissions.administrator is commented out as it does not work and replaced with True for testing purposes.

Thank you for any help and suggestions in advance.

Answer 1

Permissions is the name of the class. To get the message authors permissions, you should access the guild_permissions property of the author.

if ctx.message.author.guild_permissions.administrator:
 # you could also use guild_permissions.kick_members

Update:

A better way to validate the permissions of the person invoking the commands is by using the check feature of the commands extension, specifically the has_permissions check. For example, if you wanted to open your command only to people who had either the manage_roles permission or the ban_members permission, you could write your command like this:

from discord import Member
from discord.ext.commands import has_permissions, MissingPermissions

@bot.command(name="kick", pass_context=True)
@has_permissions(manage_roles=True, ban_members=True)
async def _kick(ctx, member: Member):
    await bot.kick(member)

@_kick.error
async def kick_error(ctx, error):
    if isinstance(error, MissingPermissions):
        text = "Sorry {}, you do not have permissions to do that!".format(ctx.message.author)
        await bot.send_message(ctx.message.channel, text)

Answer 2

You could also use decorators.

@bot.command(name = "Kick")
@bot.has_permissions(kick_user = True)
@bot.bot_has_permissions(kick_user = True)
async def _kick(ctx, member: Member):
    #Do stuff...

The advantage of checking user and bot permissions means it is easier to handle errors from either providing useful "Insufficient Permission" error messages.