text: 
  import pandas as pd
  import copy
  import io
  
  
  def on_input(msg) :
  
      # Due to input-format PROPOSED transformation into DataFrame
      df = pd.read_parquet(io.BytesIO(msg.body))
  
      # config parameter 
  
      # Sending to outport output
      att = copy.deepcopy(msg.attributes)
      out_msg = api.Message(attributes=att,body=df)
      api.send('output',out_msg)    # datatype: message
  
  api.set_port_callback('input',on_input)   # datatype: message.file
  
  