title: How to pass exception from one process to another?
body: <p>I want to raise an exception in the upload function if the running status in stop function is 'stopped'. This doesn't seem to work. I am using Pipe to pass the exception. What is wrong?</p>
  
  <pre><code>def upload(instances, u1):
      for instance in instance:
          try:
              u1.recv()
              #do_something
          except:
              #do_something_else
              continue         
  
  def stop(instances, s1):
      for instance in instances:
          RunningStatus = instance[4]
          if RunningStatus.lower() == 'stopped'.lower():
              s1.send(Exception) # I want to raise exception in upload function 
                                 # from here
  
  if __name__ == '__main__':
      s1, u1 = multiprocessing.Pipe()
      s = multiprocessing.Process(target = stop, args = (instances, s1,))
      u = multiprocessing.Process(target = upload, args = (instances, u1))
      s.start()
      u.start()
      u.join()
  </code></pre>