Basic mute

muteCog.py

import discord
import asyncio
import re
from discord.ext import commands
import sys
import traceback


time_regex = re.compile("(?:(\d{1,5})(h|s|m|d))+?")
time_dict = {"h":3600, "s":1, "m":60, "d":86400}

class TimeConverter(commands.Converter):
    async def convert(self):
        args = self.argument.lower()
        matches = re.findall(time_regex, args)
        time = 0
        for v, k in matches:
            try:
                time += time_dict[k]*float(v)
            except KeyError:
                raise commands.BadArgument("{} is an invalid time-key! h/m/s/d are valid!".format(k))
            except ValueError:
                raise commands.BadArgument("{} is not a number!".format(v))
        return time

class muteCog:
    """"""

    def __init__(self, bot):
        self.bot = bot

    @commands.command(pass_context=True)
    @commands.has_permissions(manage_roles=True)
    async def mute(self, ctx, member:discord.Member, *, time:TimeConverter = None):
        """Mutes a member for the specified time- time in 2d 10h 3m 2s format ex:
        &mute @Someone 1d"""
        role = discord.utils.get(ctx.message.server.roles, name="Muted")
        await self.bot.add_roles(member, role)
        await self.bot.say(("Muted {} for {}s" if time else "Muted {}").format(member, time))
        if time:
            await asyncio.sleep(time)
            await self.bot.remove_roles(member, role)

    #You really should use an external error handler- like the one here: https://gist.github.com/Vexs/daa1dcc92ff80fad7ca020d0f7bb4f75
    @mute.error
    async def mute_error(self, error, ctx):
        if isinstance(error, commands.CheckFailure):
            pass
        if isinstance(error, commands.BadArgument):
            await self.bot.send_message(ctx.message.channel, error)
        else:
            error = getattr(error, 'original', error)
            print('Ignoring exception in command {}:'.format(ctx.command), file=sys.stderr)
            traceback.print_exception(type(error), error, error.__traceback__, file=sys.stderr)

def setup(bot):
    bot.add_cog(muteCog(bot))