Coroutine error when running an async function

Question

I have simple function that replies with a certain message when a person uses @here or @everyone in the server

    #Ping related stuff
    if message.mention_everyone:
        if checker_ping(message.author.id):
            await message.channel.send("U used a ping")

and the function checker_ping

async def checker_ping(id):
    for i in data:
        if id == i:
            return True

where data is nothing but a list of userids

file = open('pings.txt', 'r+')
data = list(re.sub(":.", '', ''.join(file.readlines())).splitlines())

what it does is if a person with the userid specified in the ping.txt uses the @here or @everyone it sends a message as specified in the code

The problem arises when someone uses it

RuntimeWarning: coroutine 'checker_ping' was never awaited
  if checker_ping(message.author.id):
RuntimeWarning: Enable tracemalloc to get the object allocation traceback

i tried searching it up and doing various things such as storing the return value in a variable and then running it, awaiting the if statement and much more and all of them resulted in the same error

but the bot still replies

Answer 1

The root of your problem is that you tried to defined a synchronous function as an asynchronous one.

Code:

with open("stacktest/pings.txt","r+") as f:
    data = list(re.sub(":.", '', ''.join(f.readlines())).splitlines())
    print(data)

def checker_ping(userid):
    return userid in data

@bot.event
async def on_message(message:discord.Message):
    if message.mention_everyone:
        if checker_ping(str(message.author.id)):
            await message.channel.send("U used a ping")

Smaller mistakes:

• You tried comparing a number to a string. In your function message.author.id returns an integer and you compared that to a list element which is a string.
• This is not really a mistake but an optimization. I made the function return if userid is in the data with return userid in data. This creates a boolean which will either return True or False.
• You opened a file with simply file = open() but never closed it. Use with open() as something instead as i provided. (This is mostly for optimization too)