Django信号发射一次,接收两次-为什么?

我正在处理Django信号,但它们似乎被接收了两次,即使发射了一次。这是我正在使用的代码(它是一个简单的包装器,可以与Django一起使用uploadify)。

# Signal-emitting code... emits whenever a file upload is received
# ----------------------------------------------------------------
upload_recieved = django.dispatch.Signal(providing_args=['data'])

def upload(request, *args, **kwargs):
    if request.method == 'POST':
        if request.FILES:
            print 'sending signal'
            upload_recieved.send(sender='uploadify', data=request.FILES['Filedata'])
    return HttpResponse('True')

# Signal-receiving code...
# ----------------------------------------------------------------    
def upload_received_handler(sender, data, **kwargs):
    print 'upload received handler'

print 'connecting signal'
upload_recieved.connect(upload_received_handler)

(我刚注意到我的信号拼写错误)

我相信你注意到里面的打印声明了。在控制台上,显示的内容如下:

(server starts)
connecting signal

...

sending signal
upload received handler
upload received handler     # << == where is this 2nd one coming from?
127.0.0.1 - - [25/Sep/2009 07:28:22] "POST /uploadify/upload/ HTTP/1.1" 200 -

(同样奇怪的是,为什么Django在发出信号后报告页面帖子?)