Python - Multithreading - Does Lock have to be global?

Question

I am beginner of multithreading in python.
I want to use a Lock in threads. Does it have to be declared global in the thread? My code looks like this:

i = 0
lock = threading.RLock()
def do_work():
  global i
  # global lock ?????????????
  while i < len(my_list):
    lock.acquire()
    my_i = i
    i += 1
    lock.release()
    my_list[my_i].some_works()

workers = [threading.Thread(target=do_work) for _ in range(8)]
for worker in workers:
  worker.start()

Answer 1

No, it does not have to be global. You can create it in a function and then pass it to your threads as an argument like so:

i = 0

def do_work(lock):
    global i

    while i < len(my_list):
        with lock: # cleaner way to .acquire() and .release()
            my_i = i
            i += 1
         my_list[my_i].some_works()

def main():
    lock = threading.RLock()

    workers = [threading.Thread(target=do_work, args=lock,) for _ in range(8)]
    for worker in workers:
        worker.start()

main()