title: How do i handle streaming messages with Python gRPC
body: <p>I'm following this <a href="https://github.com/grpc/grpc/blob/v1.8.x/examples/python/route_guide/route_guide_client.py" rel="noreferrer">Route_Guide sample</a>.</p>
  
  <p>The sample in question fires off and reads messages without replying to a specific message. The latter is what i'm trying to achieve.</p>
  
  <p>Here's what i have so far:</p>
  
  <pre><code>import grpc
  ...
  
  channel = grpc.insecure_channel(conn_str)
  try:
      grpc.channel_ready_future(channel).result(timeout=5)
  except grpc.FutureTimeoutError:
      sys.exit('Error connecting to server')
  else:
      stub = MyService_pb2_grpc.MyServiceStub(channel)
      print('Connected to gRPC server.')
      this_is_just_read_maybe(stub)
  
  
  def this_is_just_read_maybe(stub):
      responses = stub.MyEventStream(stream())
      for response in responses:
          print(f'Received message: {response}')
          if response.something:
              # okay, now what? how do i send a message here?
  
  def stream():
      yield my_start_stream_msg
      # this is fine, i receive this server-side
      # but i can't check for incoming messages here
  </code></pre>
  
  <p>I don't seem to have a <code>read()</code> or <code>write()</code> on the stub, everything seems to be implemented with iterators.</p>
  
  <p>How do i send a message from <code>this_is_just_read_maybe(stub)</code>?
  Is that even the right approach?</p>
  
  <p>My Proto is a bidirectional stream:</p>
  
  <pre><code>service MyService {
    rpc MyEventStream (stream StreamingMessage) returns (stream StreamingMessage) {}
  }
  </code></pre>