python 操作消息队列

图示

其中P指producer，即生产者；C指consumer，即消费者。中间的红色表示消息队列，实例中表现为HELLO队列。

往队列里插入数据前，查看消息队列

$sudo rabbitmqctl  list_queues
Listing queues ...
celeryev.db53a5e0-1e6a-4f06-a9f7-2c104c4612fb
...done.

插入消息队列代码

#in_queue.py

#coding=utf8
import pika

connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()

#声明队列，如果消息发送到不存在的队列，rabbitmq会自动清除这些消息
channel.queue_declare(queue='HELLO')

for i in range(10):
    #exchange表示交换器，可以精确的制定消息应发到哪个队列，route_key设置队列的名称，body表示发送的内容
    channel.basic_publish(exchange='', routing_key='HELLO', body='Hello World!' + str(i))
    print " [%d] Sent 'Hello World!'" % i
#关闭连接
connection.close()

执行结果

$python  in_queue.py
 [0] Sent 'Hello World!'
 [1] Sent 'Hello World!'
 [2] Sent 'Hello World!'
 [3] Sent 'Hello World!'
 [4] Sent 'Hello World!'
 [5] Sent 'Hello World!'
 [6] Sent 'Hello World!'
 [7] Sent 'Hello World!'
 [8] Sent 'Hello World!'
 [9] Sent 'Hello World!'

此时查看消息队列

$sudo rabbitmqctl  list_queues
Listing queues ...
HELLO    10
celeryev.db53a5e0-1e6a-4f06-a9f7-2c104c4612fb    0
...done.

可以看到队列HELLO里面有10条数据。

读取消息队列数据

#out_queue.py

#coding=utf8
import pika

connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()

channel.queue_declare(queue='HELLO')

def callback(ch, method, properties, body):
    print " [x] Received %r" % (body,)

channel.basic_consume(callback, queue='HELLO', no_ack=True)

print ' [*] Waiting for messages. To exit press CTRL+C'
channel.start_consuming()

执行结果

$python out_queue.py
 [*] Waiting for messages. To exit press CTRL+C
 [x] Received 'Hello World!0'
 [x] Received 'Hello World!1'
 [x] Received 'Hello World!2'
 [x] Received 'Hello World!3'
 [x] Received 'Hello World!4'
 [x] Received 'Hello World!5'
 [x] Received 'Hello World!6'
 [x] Received 'Hello World!7'
 [x] Received 'Hello World!8'
 [x] Received 'Hello World!9'

此时查看消息队列

$sudo rabbitmqctl  list_queues
Listing queues ...
HELLO    0
celeryev.db53a5e0-1e6a-4f06-a9f7-2c104c4612fb    0
...done.

可以看到队列HELLO中的数据被读走了，条数为0。

未完待续

http://www.01happy.com/ubuntu-rabbitmq-and-python-practice/