Kombu - 消息发布到 rabbitmq 错误 - TypeError: 'str' object is not callable答案

【问题标题】：Kombu - Message publishing to rabbitmq error - TypeError: 'str' object is not callableKombu - 消息发布到 rabbitmq 错误 - TypeError: 'str' object is not callable
【发布时间】：2013-08-20 16:40:47
【问题描述】：

首先我想说的是，我不仅是 python 新手，而且是一般编程新手。考虑到这一点，这是我的问题。我正在尝试将一些数据发送到我的 Rabbitmq 服务器。下面是我的 Python 代码。 json_data 只是一个保存一些 json 格式数据的变量。

with Connection("amqp://username:password@test_server.local:5672/#/") as conn:
    channel = conn.channel()
    producer = Producer(channel, exchange = "test_exchange", serializer="json")

    producer.publish(json_data)

print "Message sent"

这会产生以下错误：

Traceback (most recent call last): File "test.py", line 43, in <module> producer = Producer(channel, exchange = "test_exchange", serializer="json") File "/Library/Python/2.7/site-packages/kombu/messaging.py", line 83, in __init__ self.revive(self._channel) File "/Library/Python/2.7/site-packages/kombu/messaging.py", line 210, in revive self.exchange = self.exchange(channel) TypeError: 'str' object is not callable

任何帮助将不胜感激。谢谢。

【问题讨论】：

标签： python rabbitmq amqp kombu

【解决方案1】：

在我的头撞到我的桌子后，我发现 Python 不喜欢交换的调用。然后我的同事告诉我，如果我在发布者中包含交换和路由密钥，它可能会更好。所以现在我的新代码看起来像这样。

# Creates the exchange and queue and binds them
# If already created on the server side these steps are not needed
exchange = Exchange("test_exchange", "direct", durable=True)
queue = Queue("test_q", exchange = exchange, routing_key = "test")

# The last foreword slash is the virtual host
with Connection("amqp://username:password@hostname:5672/", "/") as conn:
    channel = conn.channel()
    producer = Producer(channel, exchange = exchange, serializer="json")

    for key, value in json_data.items():
        producer.publish(exchange = exchange, routing_key = "test", body = {key:value})

print "Message sent!"

【讨论】：

【解决方案2】：

我正在回答这个问题 - 因为您的答案没有确定真正的问题，即 TypeError: 'str' object is not callable at self.exchange = self.exchange(channel) - 表明您将错误的类型传递给 exchange 参数，即传递了“str”给exchange：

producer = Producer(channel, exchange = "test_exchange", serializer="json")

解决方案：无论您在何处将值传递给“exchange”参数，它都必须是 Exchange 对象。

您的代码必须是：

with Connection("amqp://username:password@test_server.local:5672/#/") as conn:
    channel = conn.channel()
    exchange = Exchange(name='inbound') # the minimal declaration
    producer = Producer(channel, exchange=exchange, serializer="json")

    producer.publish(json_data)

print "Message sent"

有关 Exchange 参数的完整列表 - docs。

我在队列声明时遇到了同样的错误，即

queue = Queue(name=queue_name, exchange='host_tasks', routing_key=binding_key)
bound_queue = queue(channel) # only once bound, we can call declare(), purge(), delete() on exchange

所以宣布一个交易所，这样的

exchange = Exchange('host_tasks', 'direct', durable=True)
queue = Queue(name=queue_name, exchange=exchange, routing_key=binding_key)
bound_queue = queue(channel)

别忘了导入Exchange

【讨论】：