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Python中RabbitMQ如何实现进程间通信

发布时间:2020-07-02 14:38:24 来源:亿速云 阅读:255 作者:清晨 栏目:开发技术

这篇文章主要介绍Python中RabbitMQ如何实现进程间通信,文中示例代码介绍的非常详细,具有一定的参考价值,感兴趣的小伙伴们一定要看完!

RabbitMQ    消息队列

PY
threading Queue
进程Queue 父进程与子进程,或同一父进程下的多个子进程进行交互
缺点:两个不同Python文件不能通过上面两个Queue进行交互

erlong
基于这个语言创建的一种中间商
win中需要先安装erlong才能使用
rabbitmq_server start

安装 Python module

pip install pika

or

easy_install pika

or
源码

rabbit      默认端口15672
查看当前时刻的队列数
rabbitmqctl.bat list_queue

exchange
在定义的时候就是有类型的,决定到底哪些queue符合条件,可以接受消息
fanout:所有bind到此exchange的queue都可以收到消息
direct:通过routingkey和exchange决定唯一的queue可以接受消息
topic: 所有符合routingkey(此时可以是一个表达式)的routingkey所bind的queue都可以接受消息
      表达式符号说明:
      # 代表一个或多个字符     * 代表任何字符

RPC
remote procedure call           双向传输,指令<-------->指令执行结果
实现方法:                        创建两个队列,一个队列收指令,一个队列发送执行结果

用rabbitmq实现简单的生产者消费者模型

1) rabbit_producer.py

# Author : Xuefeng

import pika

connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"
))
# statement a channel
channel = connection.channel()

# create the queue, the name of queue is "hello"
# durable=True can make the queue be exist, although the service have stopped before.
channel.queue_declare(queue="hello", durable=True)

# n RabbitMQ a message can never be sent directly to queue,it always need to go through
channel.basic_publish(exchange = " ",
           routing_key = "hello",
           body = "Hello world!",
           properties = pika.BasicPropreties(
             delivery_mode=2, # make the message persistence
           )
           )
print("[x] sent 'Hello world!'")
connection.close()

2) rabbit_consumer.py

# Author : Xuefeng

import pika

connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"
))
# statement a channel
channel = connection.channel()
channel.queue_declare(queue="hello", durable=True)

def callback(ch, method, properties, body):
  '''
  Handle the recieved data
  :param ch: The address of the channel
  :param method: Information about the connection
  :param properties:
  :param body:
  :return:
  '''
  print("------>", ch, method, properties )
  print("[x] Recieved %r" % body)
  # ack by ourself
  ch.basic_ack(delivery_tag = method.delivery_tag)

# follow is for consumer to auto change with the ability
channel.basic_qos(profetch_count=1)
# no_ack = True  represent that the message cannot be transfor to next consumer,
# when the current consumer is stop by accident.
channel.basic_consume(callback,   # If have recieved message, enable the callback() function to handle the message.
           queue = "hello",
           no_ack = True)

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

用rabbitmq中的fanout模式实现广播模式

1) fanout_rabbit_publish.py

# Author : Xuefeng

import pika
import sys

# 广播模式:
# 生产者发送一条消息,所有的开通链接的消费者都可以接收到消息

connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"
))
# statement a channel
channel = connection.channel()
channel.exchange_declare(exchange="logs",
             type="fanout")
message = ' '.join(sys.argv[1:]) or "info:Hello world!"
channel.basic_publish(
  exchange="logs",
  routing_key="",
  body=message
)
print("[x] Send %r" % message)

connection.close()

2) fanout_rabbit_consumer.py

# Author : Xuefeng


import pika
import sys

connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"
))
# statement a channel
channel = connection.channel()
# exclusive 排他,唯一的 随机生成queue
result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue
print("Random queue name:", queue_name)

channel.queue_bind(exchange="logs",
          queue=queue_name)


def callback(ch, method, properties, body):
  '''
  Handle the recieved data
  :param ch: The address of the channel
  :param method: Information about the connection
  :param properties:
  :param body:
  :return:
  '''
  print("------>", ch, method, properties )
  print("[x] Recieved %r" % body)
  # ack by ourself
  ch.basic_ack(delivery_tag = method.delivery_tag)

# no_ack = True  represent that the message cannot be transfor to next consumer,
# when the current consumer is stop by accident.
channel.basic_consume(callback,   # If have recieved message, enable the callback() function to handle the message.
           queue = "hello",
           no_ack = True)

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

用rabbitmq中的direct模式实现消息过滤模式

1) direct_rabbit_publisher.py

# Author : Xuefeng
import pika
import sys

# 消息过滤模式:
# 生产者发送一条消息,通过severity优先级来确定是否可以接收到消息

connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"
))
# statement a channel
channel = connection.channel()
channel.exchange_declare(exchange="direct_logs",
             type="direct")
severity = sys.argv[1] if len(sys.argv) > 1 else "info"
message = ' '.join(sys.argv[2:]) or "info:Hello world!"

channel.basic_publish(
  exchange="direct_logs",
  routing_key=severity,
  body=message
)
print("[x] Send %r:%r" % (severity, message))

connection.close()

2) direct_rabbit_consumer.py

# Author : Xuefeng

import pika
import sys

connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"
))
# statement a channel
channel = connection.channel()

channel.exchange_declare(exchange="direct_logs",
             type="direct")

# exclusive 排他,唯一的 随机生成queue
result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue
print("Random queue name:", queue_name)

severities = sys.argv[1:]
if not severities:
  sys.stderr.write("Usage:%s [info] [warning] [error]\n" % sys.argv[0])
  sys.exit(1)

for severity in severities:
  channel.queue_bind(exchange="direct_logs",
            queue=queue_name,
            routing_key=severity)
  


def callback(ch, method, properties, body):
  '''
  Handle the recieved data
  :param ch: The address of the channel
  :param method: Information about the connection
  :param properties:
  :param body:
  :return:
  '''
  print("------>", ch, method, properties )
  print("[x] Recieved %r" % body)
  # ack by ourself
  ch.basic_ack(delivery_tag = method.delivery_tag)

# no_ack = True  represent that the message cannot be transfor to next consumer,
# when the current consumer is stop by accident.
channel.basic_consume(callback,   # If have recieved message, enable the callback() function to handle the message.
           queue = "hello",
           no_ack = True)

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


用rabbitmq中的topic模式实现细致消息过滤模式

1) topic_rabbit_publisher.py

# Author : Xuefeng

import pika
import sys

# 消息细致过滤模式:
# 生产者发送一条消息,通过运行脚本 *.info 等确定接收消息类型进行对应接收
connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"
))
# statement a channel
channel = connection.channel()
channel.exchange_declare(exchange="topic_logs",
             type="topic")
binding_key = sys.argv[1] if len(sys.argv) > 1 else "info"
message = ' '.join(sys.argv[2:]) or "info:Hello world!"

channel.basic_publish(
  exchange="topic_logs",
  routing_key=binding_key,
  body=message
)
print("[x] Send %r:%r" % (binding_key, message))

connection.close()

2) topic_rabbit_consumer.py

# Author : Xuefeng

import pika
import sys

connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"
))
# statement a channel
channel = connection.channel()

channel.exchange_declare(exchange="topic_logs",
             type="topic")

# exclusive 排他,唯一的 随机生成queue
result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue
print("Random queue name:", queue_name)

binding_keys = sys.argv[1:]
if not binding_keys:
  sys.stderr.write("Usage:%s [info] [warning] [error]\n" % sys.argv[0])
  sys.exit(1)

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


def callback(ch, method, properties, body):
  '''
  Handle the recieved data
  :param ch: The address of the channel
  :param method: Information about the connection
  :param properties:
  :param body:
  :return:
  '''
  print("------>", ch, method, properties)
  print("[x] Recieved %r" % body)
  # ack by ourself
  ch.basic_ack(delivery_tag=method.delivery_tag)


# no_ack = True  represent that the message cannot be transfor to next consumer,
# when the current consumer is stop by accident.
channel.basic_consume(callback, # If have recieved message, enable the callback() function to handle the message.
           queue="hello",
           no_ack=True)

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

用rabbitmq实现rpc操作

1) Rpc_rabbit_client.py

# Author : Xuefeng

import pika
import time
import uuid

class FibonacciRpcClient(object):
  def __init__(self):
    self.connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"))
    self.channel = self.connection.channel()
    result = self.channel.queue_declare(exclusive=True)
    self.callback_queue = result.method.queue    # 随机的生成一个接收命令执行结果的队列
    self.channel.basic_consume(self.on_response,  # 只要收到消息就调用
                  no_ack=True,
                  queue=self.callback_queue)

  def on_response(self, ch, method, props, body):
    if self.corr_id == props.correlation_id:
      self.response = body

  def call(self,n):
    self.response = None
    self.corr_id = str(uuid.uuid4())
    self.channel.basic_publish(
      exchange="",
      routing_key="rpc_queue",
      properties=pika.BasicPropreties(
        rely_to=self.callback_queue,
        correlation_id=self.corr_id     # 通过随机生成的ID来验证指令执行结果与指令的匹配性
      ),
      body=str(n)
    )
    while self.response is None:
      self.connection.process_data_events()  # 非阻塞版的start_consume,有没有消息都继续
      print("no message...")
      time.sleep(0.5)
    return int(self.response)

fibonacci_rcp = FibonacciRpcClient()

print("[x] Requesting fib(30)")
response = fibonacci_rcp.call(30)
print("[x] Rec %r" % response)

2) Rpc_rabbit_server.py

# Author : Xuefeng

import pika
import sys

connection = pika.BlockingConnection(pika.Connection.Parameters(
  "localhost"
))
# statement a channel
channel = connection.channel()

channel.queue_declare(queue="rpc_queue")

def fib(n):
  if n == 0:
    return 0
  elif n == 1:
    return 1
  else:
    return fib(n-1)+fib(n-2)

def on_request(ch, method, props, body):
  n = int(body)
  print("[.] fib(%s)" % n)
  response = fib(n)
  ch.basic_publish(
    exchange="",
    routing_key=props.rely_to,
    properties=pika.BasicPropreties(correlation_id=\
                    props.correlation),
    body = str(body)
  )
  ch.basic_ack(delivery_tag=method.delivery_tag)

channel.basic_qos(prefetch_count=1)
channel.basic_consume(on_request, queue="rpc_queue")

print("[x] Awaiting RPC requests")
channel.start_consumeing()



channel.exchange_declare(exchange="direct_logs",
             type="direct")

# exclusive 排他,唯一的 随机生成queue
result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue
print("Random queue name:", queue_name)

severities = sys.argv[1:]


以上是Python中RabbitMQ如何实现进程间通信的所有内容,感谢各位的阅读!希望分享的内容对大家有帮助,更多相关知识,欢迎关注亿速云行业资讯频道!

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