Discord.py 和多线程

Question

Im kinda new to programing, so this question may be dumb or easy for some... I have a question regarding multithreading and looking for some documentation or link to understand it more.

Lets suppose I have a Discord bot that performs a function when called. (wrote a simple sum as an example)

@client.command()
async def example(ctx):

    # (lets assume the code here is to grab the user input value
    # from two messages and transform the messages into int variables called 
    # "first" and "second")


first = int(msg1.content)
second = int(msg2.content)


# Function to perform

    def sum():
        time.sleep(5) # added a sleep to simulate the "complex" formula performing calculations and a web request.

        result = number1 + number2
        return result


    # Thread formula

    def thread():
        with ThreadPoolExecutor(max_workers = 2) as executor:
            executor.submit(sum)

    thread()
        

    
    # Send the result 
    await ctx.author.send(f'Waited 5 seconds and this is the result {thread()}')


client.run(TOKEN)

In my mind what's happening is that the thread is calling the sum function. Of course is wrong because I get a "None" value as a result.

Can anybody point me out to some useful resources or documentation on how to implement multithreading or multiprocessing?

Or give some advice on how to handle this situation. \\

Is multiprocessing the solution? The task is not CPU intensive, so I thought that multithreading was the way to go.

The goal is for the bot to be able to handle multiple requests at the same time. Right now it does, but when the requests take a little bit more, it becomes slow or sometimes it doesn't even sends the last messages. I was testing on Repl.it and it showed a "low memory" (or something like that. And I assume its because Replit only gives like 0.4 vCPU so no big deal), which made me research about multithreading.

Thanks in advance!

Answer 1

sum() is returning a value, but you're getting the answer from the wrong place. And by the way, you shouldn't call a function sum() , since that's already a built-in Python function. But that's another matter.

executor.submit() returns a Future `. That future will get the result when the sum() has finished

You want to write:

    def thread():
        with ThreadPoolExecutor(max_workers = 2) as executor:
            return executor.submit(sum)

    future = thread()
    return future.result()