helpful discord.py converters

converters.py

import re
import discord
from discord.ext import commands


class FetchedUser(commands.Converter):
    async def convert(self, ctx, argument):
        if not argument.isdigit():
            raise commands.BadArgument('Not a valid user ID.')
        try:
            return await ctx.bot.fetch_user(argument)
        except discord.NotFound:
            raise commands.BadArgument('User not found.')
        except discord.HTTPException:
            raise commands.BadArgument('An error occurred while fetching the user.')


class GlobalChannel(commands.Converter):
    async def convert(self, ctx, argument):
        try:
            return await commands.TextChannelConverter().convert(ctx, argument)
        except commands.BadArgument:
            # Not found... so fall back to ID + global lookup
            try:
                channel_id = int(argument, base=10)
            except ValueError:
                raise commands.BadArgument(f'Could not find a channel by ID {argument!r}.')
            else:
                channel = ctx.bot.get_channel(channel_id)
                if channel is None:
                    raise commands.BadArgument(f'Could not find a channel by ID {argument!r}.')
                return channel


class Guild(commands.Converter):
    async def convert(self, ctx, argument):
        if not argument.isdigit():
            raise commands.BadArgument('Not a valid guild ID.')
        try:
            return ctx.bot.get_guild(argument)
        except discord.NotFound:
            raise commands.BadArgument('Guild not found.')
        except discord.HTTPException:
            raise commands.BadArgument('An error occurred while fetching the guild.')


class OptionFlags(commands.Converter):
    pattern = re.compile(r"""--(\S+)(?:\s+(?!--)((?:.(?!--))*\S))?""")
    
    async def convert(self, ctx, argument):
        result = {}
        matches = self.pattern.finditer(argument)
        for match in matches:
            key = match.group(1)
            value = match.group(2) or True
            result[key] = value
        return result


class Command(commands.Converter):
    async def convert(self, ctx, argument):
        command = ctx.bot.get_command(argument)
        if command:
            return command
        else:
            raise commands.BadArgument("A command with this name could not be found.")


class Cog(commands.Converter):
    async def convert(self, ctx, argument):
        cog = ctx.bot.get_cog(argument)
        if cog:
            return cog
        else:
            raise commands.BadArgument("A cog with this name could not be found.")