例如：

  with ThreadPoolExecutor(max_workers=2, ) as executor:
        while 1:
            #这里会一直pop出来，我想设置了max_workers=2，就pop2个出来，线程执行完了，再进行pop，怎么写？做个计数吗？
            data = redis.blpop('key')
            future = executor.submit(blpop_task, data)

如果一直取数据的话，，为什么要让线程执行结束，然后再启动新的线程去做同样的事情，，，，

""""""
from queue import Queue
from threading import Thread

data_queue = Queue(maxsize=2)


def task():
    while True:
        data = data_queue.get()
        print("task exec finished: %s" % data)
        
        
if __name__ == '__main__':
    # 启动任务
    t1 = Thread(target=task, daemon=False)
    t1.start()
    t2 = Thread(target=task, daemon=False)
    t2.start()
    i = 1
    while True:
        data_queue.put(i)
        i += 1