##### queue.消息队列
```python
from threading import Thread
from queue import Queue
class MsgProducer(Thread):
# 生产者线程，生产消息放进队列，阻塞至全部放进去
def __init__(self, name: str, count: int, queue: Queue):
super().__init__()
self.setName(name)
self.count = count
self.queue = queue
def run(self) -> None:
for n in range(self.count):
msg = f'{self.getName()} - {n}'
self.queue.put(msg, block=True)
class MsgConsumer(Thread):
# 消费者线程，队列提取消息
def __init__(self, name: str, queue: Queue, pth: Thread):
super().__init__()
self.setName(name)
self.queue = queue
self.pth = pth
def run(self) -> None:
while self.pth.is_alive() or not self.queue.empty():
msg = self.queue.get(block=True)
print(f'{self.getName()} - {msg}\n', end='')
nqueue = Queue(3)
threads = list()
threads.append(MsgProducer('PA', 5, nqueue))
threads.append(MsgProducer('PB', 5, nqueue))
threads.append(MsgConsumer('CA', nqueue, threads[0]))
threads.append(MsgConsumer('CB', nqueue, threads[1]))
for t in threads:
t.start()
for t in threads:
t.join()
```