Discord.py how to run two loops at once?

Question

Python

Here is the code:

from threading import Thread
import discord
from discord.ext import commands

bot = commands.Bot(command_prefix='!')


@bot.command(pass_context=True)
async def f(ctx):
    for i in range(3):
        await ctx.send('Test2')


@bot.command(pass_context=True)
async def f_2(ctx):
    for i in range(3):
        await ctx.send('Test')


th_1, th_2 = Thread(target=f), Thread(target=f_2)


@bot.command(pass_context=True)
async def test1(ctx):
    th_1.start(), th_2.start()
    th_1.join(), th_2.join()

I need the "test1" command to run two cycles 'f' and 'f_2' at once, but it gives an error... How to implement it correctly?