A simple python thread based random number generator

lib.py

import threading
x=0 #to get a random number
killswitch = False # To kill thread after use
def threaded_return(que):
    """
    Returning data from thread safely (Returns current value of x)
    :param que:
    :return:
    """
    global x
    que.put(x)

def thread_fn():
    """
    This is a threaded function (counts from 0 to 10000 for infinite times untill killswitch is True)
    :return:
    """
    global x
    global killswitch
    while True:
        if killswitch:
            break
        if x==10000:
            x=0
            continue
        x=x+1

def kill():
    """
    To send kill signal to the thread
    :return:
    """
    global killswitch
    killswitch = True
    global th
    th.join()

def run():
    global th
        th = threading.Thread(target=thread_fn)
        th.start()

main.py

import queue
que = queue.Queue()
import lib

def main():
    lib.run()
    print("Main function...")

    for i in range(20):
        lib.threaded_return(que=que)
        x = str(que.get())
        print("Returned from queue: "+x)
    lib.kill()
    exit()

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        lib.kill()
        exit(0)