Exchanging data between a PyQt5 app asynchronously

batton

I have a need to create a PyQt5 app that responds to asynchronous messages. I have a langgraph LLM application and I would like to pass data that it generates to a PyQt5 app to display the data, allow changes, and then pass data back to the Langgraph app.
I know how to send the message from langgraph asynchronously using asyncio queues, but I'm an absolute beginner with PyQt.

I think the way this works is like this:

Langgraph has an asynchronous python function that puts the data to an async queue using the asyncio.Queue put() method.
somewhere running in the PyQt app is aa async function that periodically executes and peforms asyncio.Queue get() method to read the queue.
PyQt app displays the data which after modification is sent back to the Langgraph function by another call to an asyncio.Queue put() method.
Langgraph function reads the queue once again with asyncio.Queue get() method and carries on.

Can anybody please give me some pointers regarding if this is possible, and how I would do it in PyQt. It's only the PyQt part that is problematic for me. I don't need specific code examples (of course if snippets help, feel free), but rather a description of what components to use if it is possible.

SGaist

Hi and welcome to devnet,

I think you will be interested by the new Qt Asyncio module.

It integrate the asyncio loop and Qt's event loop.

For the rest what would you need to know ?

batton

Thank you! Clearly I have a lot to learn. I was really wanting to do something very simple if possible.
Below is a proof of concept using two functions, and how I would exchange a message between them:

import asyncio


async def function_1(sendQueue, receiveQueue):
    # Send a message to Function_2
    await sendQueue.put("Hello Function_2")
    print("Function_1: Sent 'Hello Function_2'")

    # Wait to receive a message from Function_2
    message = await receiveQueue.get()
    print(f"Function_1: Received '{message}'")


async def function_2(sendQueue, receiveQueue):
    # Wait to receive a message from Function_1
    message = await sendQueue.get()
    print(f"Function_2: Received '{message}'")

    # Wait for 2 seconds
    await asyncio.sleep(2)

    # Send a message to Function_1
    await receiveQueue.put("Hello Function_1")
    print("Function_2: Sent 'Hello Function_1'")


async def main():
    # Create the queues
    sendQueue = asyncio.Queue()
    receiveQueue = asyncio.Queue()

    # Run both functions concurrently
    await asyncio.gather(
        function_1(sendQueue, receiveQueue),
        function_2(sendQueue, receiveQueue)
    )

If you were to replace Function_1 with my langgraph node function, and Function_2 as something in the PyQt app that would be triggered on a button press for example, then you would have an idea of what I am trying to achieve.

SGaist

Then I think the two examples linked in the doc I posted above show how to implement that kind of things.

batton

Thank you once again! I will dig into those examples.