Python中的azure.servicebus消息ValueError

Question

I'm playing around with Microsoft Azure to send messages to a subscription in the Cloud via a Topic. But ran into issues with Microsofts python sdk, specifically a ValueError when deserializing a message from the cloud.

This is my code

bus_service = ServiceBusService(
    service_namespace='"<namegoeshere>"',
    shared_access_key_name='"<nameofkeygoeshere>"',
    shared_access_key_value='"<keyvaluegoeshere>"')

bus_service.create_topic('topic')
bus_service.create_subscription('topic', 'AllMessages')
msg = Message("HelloWorld")
bus_service.send_topic_message('topic', msg)

// at this point I can see the message arrive in my Azure portal

// then it crashes when I try to retrieve the message I just sent
msg = bus_service.receive_subscription_message('topic', 'AllMessages', peek_lock=False)
print(msg.body)

This is the error:

Traceback (most recent call last):
  File "C:/Users/user/PycharmProjects/test/helloworld.py", line 59, in <module>
msg = bus_service.receive_subscription_message('topic', 'AllMessages', peek_lock=False)
  File "D:\Program Files\Anaconda2\lib\site-packages\azure\servicebus\servicebusservice.py", line 976, in receive_subscription_message
timeout)
  File "D:\Program Files\Anaconda2\lib\site-packages\azure\servicebus\servicebusservice.py", line 764, in read_delete_subscription_message
return _create_message(response, self)
  File "D:\Program Files\Anaconda2\lib\site-packages\azure\servicebus\_serialization.py", line 101, in _create_message
elif str(int(float(value))) == value:
ValueError: could not convert string to float: max-age=31536000

Process finished with exit code 1

I went into the class and had a look:

def _create_message(response, service_instance):
    ''' Create message from response.

    response:
        response from service bus cloud server.
    service_instance:
        the service bus client.
'''
respbody = response.body
custom_properties = {}
broker_properties = None
message_type = None
message_location = None

# gets all information from respheaders.
for name, value in response.headers:
    if name.lower() == 'brokerproperties':
        broker_properties = json.loads(value)
    elif name.lower() == 'content-type':
        message_type = value
    elif name.lower() == 'location':
        message_location = value
    elif name.lower() not in ['content-type',
                              'brokerproperties',
                              'transfer-encoding',
                              'server',
                              'location',
                              'date']:

        if '"' in value:
            value = value[1:-1]
            try:
                custom_properties[name] = datetime.strptime(
                    value, '%a, %d %b %Y %H:%M:%S GMT')
            except ValueError:
                custom_properties[name] = value
        else:  # only int, float or boolean
            if value.lower() == 'true':
                custom_properties[name] = True
            elif value.lower() == 'false':
                custom_properties[name] = False
            # int('3.1') doesn't work so need to get float('3.14') first
            elif str(int(float(value))) == value:    # <---- Exception !
                custom_properties[name] = int(value)
            else:
                custom_properties[name] = float(value)

Any ideas what I could do to resolve this?

Answer 1

This is a bug is version 0.20.1, see Change Log in Pypi. From 0.20.2 released 2016-06-28, the bug is fixed. https://pypi.python.org/pypi/azure-servicebus

Reference issue: https://github.com/Azure/azure-sdk-for-python/issues/669

Thank you,

Answer 2

I had to change Microsofts _serialization.py file to get it to work. Wrapping the offending block in a try/except block:

if '"' in value:
    value = value[1:-1]
    try:
        custom_properties[name] = datetime.strptime(
            value, '%a, %d %b %Y %H:%M:%S GMT')
    except ValueError:
        custom_properties[name] = value
else:  # only int, float or boolean
    try:
        if value.lower() == 'true':
            custom_properties[name] = True
        elif value.lower() == 'false':
            custom_properties[name] = False
        # int('3.1') doesn't work so need to get float('3.14') first
        elif str(int(float(value))) == value:
            custom_properties[name] = int(value)
        else:
            custom_properties[name] = float(value)
    except ValueError:
        custom_properties[name] = value

Seems to work so far..

So, Microsoft... Any chance of a job?...