code: def error_msg_from_exception(e):
      
      msg = ''
      if hasattr(e, 'message'):
          if isinstance(e.message, dict):
              msg = e.message.get('message')
          elif e.message:
              msg = '{}'.format(e.message)
      return msg or '{}'.format(e)
docs: Translate exception into error message
  
      Database have different ways to handle exception. This function attempts
      to make sense of the exception object and construct a human readable
      sentence.
  
      TODO(bkyryliuk): parse the Presto error message from the connection
                       created via create_engine.
      engine = create_engine('presto://localhost:3506/silver') -
        gives an e.message as the str(dict)
      presto.connect('localhost', port=3506, catalog='silver') - as a dict.
      The latter version is parsed correctly by this function.