python采用pika库使用rabbitmq（八）有选择的接收消息(exchange type=direct)

RabbitMQ还支持根据关键字发送，即：队列绑定关键字，发送者将数据根据关键字发送到消息exchange，exchange根据 关键字 判定应该将数据发送至指定队列。

 1 import pika
 2 import sys
 3  
 4 connection = pika.BlockingConnection(pika.ConnectionParameters(
 5         host='localhost'))
 6 channel = connection.channel()
 7  
 8 channel.exchange_declare(exchange='direct_logs',
 9                          type='direct')
10  
11 severity = sys.argv[1] if len(sys.argv) > 1 else 'info'
12 message = ' '.join(sys.argv[2:]) or 'Hello World!'
13 channel.basic_publish(exchange='direct_logs',
14                       routing_key=severity,
15                       body=message)
16 print(" [x] Sent %r:%r" % (severity, message))
17 connection.close()

publisher