我正在尝试开发一个使用pika和线程模块的Python 3.6脚本。
我有一个问题，我认为是由我的A）对Python和一般编码非常陌生造成的，B）当函数在单独的线程中运行时，我不理解如何在函数之间传递变量，并且已经在接收函数名的末尾传递了一个参数。
我这样认为的原因是，当我不使用线程时，我可以通过调用接收函数名在函数之间传递变量，并提供要传递的变量，在括号中，一个基本的例子如下所示：

def send_variable():
    body = "this is a text string"
    receive_variable(body)

def receive_variable(body):
    print(body)

运行时，将打印：

this is a text string

下面是我需要使用线程工作的代码的工作版本-这使用了直接函数（没有线程），我使用pika通过pika回调函数从（RabbitMQ）队列接收消息，然后将“callback”函数中接收的消息体传递给“processing function”：

import pika
...mq connection variables set here...

# defines username and password credentials as variables set at the top of this script
    credentials = pika.PlainCredentials(mq_user_name, mq_pass_word)

# defines mq server host, port and user credentials and creates a connection
    connection = pika.BlockingConnection(pika.ConnectionParameters(host=mq_host, port=mq_port, credentials=credentials))

# creates a channel connection instance using the above settings
    channel = connection.channel()

# defines the queue name to be used with the above channel connection instance
    channel.queue_declare(queue=mq_queue)

def callback(ch, method, properties, body):

# passes (body) to processing function
    body_processing(body)

# sets channel consume type, also sets queue name/message acknowledge settings based on variables set at top of script
    channel.basic_consume(callback, queue=mq_queue, no_ack=mq_no_ack)
# tells the callback function to start consuming
    channel.start_consuming()
# calls the callback function to start receiving messages from mq server
    callback()
# above deals with pika connection and the main callback function

def body_processing(body):
    ...code to send a pika message every time a 'body' message is received...

这很好用，但是我想把它翻译成在一个使用线程的脚本中运行。当我这样做的时候，我必须提供参数'channel'给在它自己的线程中运行的函数名-当我尝试包括'body'参数，这样'processing_function'看起来就像下面这样：

def processing_function(channel, body):

我收到一个错误消息：

[function_name] is missing 1 positional argument: 'body'

我知道使用线程时需要更多的代码，我在下面包含了我用于线程的实际代码，以便您可以看到我在做什么：

...imports and mq variables and pika connection details are set here...

def get_heartbeats(channel):
channel.queue_declare(queue=queue1)
#print (' [*] Waiting for messages. To exit press CTRL+C')

    def callback(ch, method, properties, body):

        process_body(body)

        #print (" Received %s" % (body))

    channel.basic_consume(callback, queue=queue1, no_ack=no_ack)
    channel.start_consuming()

def process_body(channel, body):
    channel.queue_declare(queue=queue2)
    #print (' [*] Waiting for Tick messages. To exit press CTRL+C')

# sets the mq host which pika client will use to send a message to
    connection = pika.BlockingConnection(pika.ConnectionParameters(host=mq_host))
# create a channel connection instance
    channel = connection.channel()
# declare a queue to be used by the channel connection instance
    channel.queue_declare(queue=order_send_queue)
# send a message via the above channel connection settings
    channel.basic_publish(exchange='', routing_key=send_queue, body='Test Message')
# send a message via the above channel settings
# close the channel connection instance
    connection.close()

def manager():

# Channel 1 Connection Details - =======================================================================================

    credentials = pika.PlainCredentials(mq_user_name, mq_password)
    connection1 = pika.BlockingConnection(pika.ConnectionParameters(host=mq_host, credentials=credentials))
    channel1 = connection1.channel()

# Channel 1 thread =====================================================================================================
    t1 = threading.Thread(target=get_heartbeats, args=(channel1,))
    t1.daemon = True
    threads.append(t1)
    # as this is thread 1 call to start threading is made at start threading section

# Channel 2 Connection Details - =======================================================================================

    credentials = pika.PlainCredentials(mq_user_name, mq_password)
    connection2 = pika.BlockingConnection(pika.ConnectionParameters(host=mq_host, credentials=credentials))
    channel2 = connection2.channel()

# Channel 2 thread ====================================================================================================
    t2 = threading.Thread(target=process_body, args=(channel2, body))
    t2.daemon = True
    threads.append(t2)
    t2.start()  # as this is thread 2 - we need to start the thread here

# Start threading
t1.start()  # start the first thread - other threads will self start as they call t1.start() in their code block
for t in threads: # for all the threads defined
    t.join()  # join defined threads

manager()  # run the manager module which starts threads that call each module

这在运行时产生错误

process_body() missing 1 required positional argument: (body)

我不明白为什么会这样也不知道该怎么解决