Small code to listen to a postgress NOTIFY while doing a normal function at the same time. No async job (except the actual listener). The NOTIFY listener is launched with asyncio in another thread while the normal job is executed in the main thread

Postgresql_liten_notify_while_doing_other_synchronous_job.py

import asyncio
import logging
import os
import psycopg2
import threading
import time

from dotenv import find_dotenv, load_dotenv

def listen_to_notifications():
    try:
        load_dotenv(find_dotenv())
        
        conn = psycopg2.connect(
            host=os.environ.get('POSTGRES_IP'),
            port=os.environ.get('POSTGRES_PORT'),
            user=os.environ.get('POSTGRES_USER'),
            password=os.environ.get('POSTGRES_PASSWORD'),
            database=os.environ.get('POSTGRES_DB_DPMC_NAME')
        )
        cursor = conn.cursor()
        cursor.execute("LISTEN channel;")   # Modify the channel here
        conn.commit()

        def handle_notify():
            conn.poll()
            for notify in conn.notifies:
                print(notify.payload)       # Your code here
            conn.notifies.clear()

        loop = asyncio.new_event_loop()     # No event loop exist in the new thread, so we create one
        asyncio.set_event_loop(loop)
        loop.add_reader(conn, handle_notify)
        loop.run_forever()
    
    except KeyboardInterrupt:
        print("Infinite loop stopped.")


def infinite_loop():
    try:
        while True:
            print("Executing synchronous task...")
            time.sleep(0.4)  # Simulate work
    except KeyboardInterrupt:
        print("Infinite loop stopped.")


if __name__ == "__main__":
    notification_thread = threading.Thread(target=listen_to_notifications, daemon=False)        # Daemon=False  --> The thread is closed when the main thread is finicshed
    notification_thread.start()
    
    # Run the infinite loop in the main thread (simulate a job)
    infinite_loop()     # Your code here

In postgreSQL :

NOTIFY channel, 'Your data to transmit'