code: def write_bytes(out_data, encoding="ascii"):
      
      if sys.version_info[0] >= 3:
          if isinstance(out_data, type("")):
              if encoding == "utf-8":
                  return out_data.encode("utf-8")
              else:
                  return out_data.encode("ascii", "ignore")
          elif isinstance(out_data, type(b"")):
              return out_data
      else:
          if isinstance(out_data, type("")):
              if encoding == "utf-8":
                  return out_data.encode("utf-8")
              else:
                  return out_data.encode("ascii", "ignore")
          elif isinstance(out_data, type(str(""))):
              return out_data
      msg = "Invalid value for out_data neither unicode nor byte string: {}".format(
          out_data
      )
      raise ValueError(msg)
docs: Write Python2 and Python3 compatible byte stream.