How to get the return value from pynput.keyboard.Listener Thread?

Question

I would like to get the return value of a function within pynput.keyboard.Listener. The only thing I thought it could work was using global variables. Also ThreadPool, but I think it will not work in this predefine threading.thread from pynput called keyboard.Listener()

SAMPLE CODE

message = ' '
keys = []

def write_keys(keys):
    global message
    for key in keys:
        k = str(key).replace(f'{chr(39)}', '')
        print(k)
        message += k
    if len(message) == 10:
        return message # return this value

def on_press(key):
    global keys
    keys.append(key)
    write_keys(keys)
    keys = []

keyboard_thread = keyboard.Listener(on_press=on_press)
keyboard_thread.start()
#messages = return the message value

Answer 1

If you want to avoid using global variable.You could use ThreadQueue.

from pynput import keyboard
from queue import Queue

message = ''
keys = []

queue = Queue()

def write_keys(keys):
    global message
    for key in keys:
        k = str(key).replace(f'{chr(39)}', '')
        print(k)
        message += k
    if len(message) == 10:
        queue.put(message)

def on_press(key):
    global keys
    keys.append(key)
    write_keys(keys)
    keys = []

keyboard_thread = keyboard.Listener(on_press=on_press)
keyboard_thread.start()
while True:
    messages = queue.get()
    print(messages)