Python RabbitMQ

需要安装erlang和RabbitMQ

1. 一对一

producer：

import pika

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

# 声明queue
channel.queue_declare(queue='hello',durable=True) # durable=True,将队列持久化，哪怕 RabbitMQ服务重启，此队列依然存在

# RabbitMQ a message can never be sent directly to the queue, it always needs to go through an exchange.
channel.basic_publish(exchange='',
                      routing_key='hello',
                      body='Hello World!',
                      properties=pika.BasicProperties(delivery_mode=2) # 将队列中的消息也持久化
                      )
print(" [x] Sent 'Hello World!'")
connection.close()

consumer:

import pika
import time

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

# 为什么又声明一遍这个队列（生产者已经声明过了），因为如果消费者先运行起来，此时又没有声明的话，会报错，
# 所以在这里重新声明一遍，防止出错罢了。
channel.queue_declare(queue='hello',durable=True) # durable=True,将队列持久化，哪怕 RabbitMQ服务重启，此队列依然存在


def callback(ch, method, properties, body):
    print('-->',ch,method,properties)
    # time.sleep(30)
    print(" [x] Received %r" % body)
    ch.basic_ack(delivery_tag=method.delivery_tag)   # 手动应答，只有消费者确认了，才会从队列删除

channel.basic_qos(prefetch_count=1)  # 只要一个消费者的队列中还有1个消息,就不继续推送给这个消费者

channel.basic_consume('hello',
                      callback,
                      # auto_ack=True  # 自动应答，消费者一收到消息，消息就自动从队列中删除，如果消费者没有处理完此消息，也会删除。
                      )

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

2. 一对多广播：fanout

producer：

import pika
import sys

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

channel.exchange_declare(exchange='logs',     # 随意声明一个叫 logs 的 exchange
                         exchange_type='fanout') # 类型用fanout,可以对所有绑定此exchange的channel进行广播

message = "info: Hello World!"
channel.basic_publish(exchange='logs',
                      routing_key='',  # 不设定routing_key,就是对所有绑定此exchange的channel进行推送消息
                      body=message)
print(" [x] Sent %r" % message)
connection.close()

consumer：

import pika

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

channel.exchange_declare(exchange='logs',
                         exchange_type='fanout')

result = channel.queue_declare('',exclusive=True)  # queue名字为空,rabbit会随机分配一个名字,exclusive=True会在使用此queue的消费者断开后,自动将queue删除
queue_name = result.method.queue

channel.queue_bind(exchange='logs',  # 绑定名为logs的exchange
                   queue=queue_name)

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

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

channel.basic_consume(queue_name,
                      callback,
                      auto_ack=True)

channel.start_consuming()

3. 有选择的接受消息：direct

producer：

import pika
import sys

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

channel.exchange_declare(exchange='direct_logs',
                         exchange_type='direct')

severity = sys.argv[1] if len(sys.argv) > 1 else 'info'
message = ' '.join(sys.argv[2:]) or 'Hello World!'
channel.basic_publish(exchange='direct_logs',
                      routing_key=severity,
                      body=message)
print(" [x] Sent %r:%r" % (severity, message))
connection.close()

consumer：

import pika
import sys

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

channel.exchange_declare(exchange='direct_logs', # 声明一个exchange的名字和类型
                         exchange_type='direct')

result = channel.queue_declare('',exclusive=True)# 随机生成一个唯一的queue
queue_name = result.method.queue

severities = sys.argv[1:]  # 从命令行获取参数
if not severities:
    # sys.stderr.write("Usage: %s [info] [warning] [error]\n" % sys.argv[0])
    # sys.exit(1)
    severities = ['info']


for severity in severities:
    channel.queue_bind(exchange='direct_logs', # 绑定到direct_logs上
                       queue=queue_name,
                       routing_key=severity) # 指向相应的生产者上

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


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

channel.basic_consume(queue_name,
                      callback,
                      auto_ack=True)
channel.start_consuming()

3. 过滤特殊字段的消息：topic

producer：

import pika
import sys

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

channel.exchange_declare(exchange='topic_logs',
                         exchange_type='topic')

routing_key = sys.argv[1] if len(sys.argv) > 1 else 'anonymous.info'
message = ' '.join(sys.argv[2:]) or 'Hello World!'
channel.basic_publish(exchange='topic_logs',
                      routing_key=routing_key,
                      body=message)
print(" [x] Sent %r:%r" % (routing_key, message))
connection.close()

consumer：

import pika
import sys

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

channel.exchange_declare(exchange='topic_logs',
                         exchange_type='topic')

result = channel.queue_declare('',exclusive=True)
queue_name = result.method.queue

binding_keys = sys.argv[1:]
if not binding_keys:
    # sys.stderr.write("Usage: %s [binding_key]...\n" % sys.argv[0])
    # sys.exit(1)
    binding_keys = ['anonymous.*'] # *代表匹配任意字符,# 代表匹配所有:binding_keys=['#','*.abc','aaa.*']

for binding_key in binding_keys:
    channel.queue_bind(exchange='topic_logs',
                       queue=queue_name,
                       routing_key=binding_key)

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


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


channel.basic_consume(queue_name,
                      callback,
                      auto_ack=True)

channel.start_consuming()

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