Rabbitmq and Python NameError: global name problem

Question

我正在尝试向 Rabbitmq 发送 JSON。这是我的制作人，它工作正常：

import pika
import json

credentials = pika.PlainCredentials('admin', '123')
parameters = pika.ConnectionParameters('192.168.1.11',
                                       5672,
                                       '/',
                                       credentials)
connection = pika.BlockingConnection(parameters)
channel = connection.channel()
channel.queue_declare(queue='myapp')

message = {'fname': 'test', 'lname': 'test'}

channel.basic_publish(exchange='',
                      routing_key='myapp',
                      body=json.dumps(message),
                      properties=pika.BasicProperties(
                         delivery_mode = 2,

                      ))
print(" [x] Sent %r" % message)

connection.close()

这是接收器，但不正常：

import pika
import time
import json

credentials = pika.PlainCredentials('admin', '123')
parameters = pika.ConnectionParameters('192.168.1.12',
                                       5672,
                                       '/',
                                       credentials)
connection = pika.BlockingConnection(parameters)
channel = connection.channel()
channel.queue_declare(queue='myapp')

def callback(ch, method, properties, body):
    myjson = json.loads(body)
    global fname
    global lname
    fname = myjson["fname"]
    lname = myjson["lname"]
    my_func(fname,lname)

channel.basic_qos(prefetch_count=1)
channel.basic_consume(queue='myapp',
                      auto_ack=True,
                      on_message_callback=callback)
channel.start_consuming()
def my_func(fname,lname):
    pass

当我运行脚本接收器显示以下问题：

NameError: 全局名称 'my_func' 未定义

Answer 1

问题是由于您 receiver.py

中的这个函数引起的

channel.start_consuming()

该函数将在那里阻止程序并阻止它看到 my_func()。另一方面，代码分析工具，例如pylint，很可能无法检测到此类错误。

一个简单的解决方案是将代码更改为

def callback(ch, method, properties, body):
    myjson = json.loads(body)
    global fname
    global lname
    fname = myjson["fname"]
    lname = myjson["lname"]
    my_func(fname,lname)

def my_func(fname,lname):
    pass

channel.basic_qos(prefetch_count=1)
channel.basic_consume(queue='myapp',
                      auto_ack=True,
                      on_message_callback=callback)
channel.start_consuming()

一个更复杂的解决方案是以异步方式创建您自己的 class 或方法和运行 start_consuming()。这是我的例子：

def listen(self, exchange, routing, callback):
    self.ReceiveChannel = self.connection.channel()
    consumer_thread = threading.Thread(target=self.__consumer__, args=[exchange, routing, callback])
    consumer_thread.start()

Rabbitmq and Python NameError: global name problem

Rabbitmq and Python NameError: global name problem

python

rabbitmq

pika