Worker thread is doing some task, logger thread log printed messages

sharing_memory_thread.py

from threading import Thread, Event


event = Event()


def worker(number, outputs, exit_code):
    msg = "=== Table de mulitiplication par {}".format(number)
    outputs.append(msg)

    for i in range(1, number):
        msg = "{} * {} = {}".format(i, number, i*number)
        outputs.append(msg)
        print(msg)

    exit_code[0] = 0


def logger(outputs, exit_code):
    log = []
    i = 0
    while 1:
        n_log = len(log)
        n_out = len(outputs)

        if n_log < n_out:
            print("log : {}".format(outputs[i]))
            log.append(outputs)
            i = i + 1

        if exit_code[0] == 0 and n_log == n_out:
            break


out = []
ex_code = [-1]

t1 = Thread(target=worker, args=(12, out, ex_code, ))
t2 = Thread(target=logger, args=(out, ex_code, ))

t1.start()
t2.start()