python - Python 保存プロセス (ファイル ハンドラーを閉じる)

Question

この基本的な例を確認してください

def queue_add():
    #this will exit when all lines from the 
    #file are added in the Queue
    with open('get_from.txt') as f:
        for line in f:
            q.add(line.strip())

def queue_save():
    #when to trigger save_to.close()?!?!
    save_to = open('save_to.txt')
    while True:
        data = q.get() #this functions blocks if `q` is empty, so how to know
                       #when to close the file handler `save_to`??
        save_to.write(data)

def worker():
    #this is daemon process 
    while True:
        #work with file from 
        get = q.get()
        #work with data
        q_done.put('processed data')
        q.task_done()

q = Queue()
q_done = Queue()
#starts the processes here..

だから私の質問はqueue_save()、done_q からすべてのデータを処理して保存し、file_handler を閉じる方法を知る方法ですか?