content: import io
  import ntpath
  import base64
  
  # region Utils for Download component
  
  
  def send_file(path, filename=None, type=None):
      """
      Convert a file into the format expected by the Download component.
      :param path: path to the file to be sent
      :param filename: name of the file, if not provided the original filename is used
      :param type: type of the file (optional, passed to Blob in the javascript layer)
      :return: dict of file content (base64 encoded) and meta data used by the Download component
      """
      # If filename is not set, read it from the path.
      if filename is None:
          filename = ntpath.basename(path)
      # Read the file contents and send it.
      with open(path, "rb") as f:
          return send_bytes(f.read(), filename, type)
  
  
  def send_bytes(src, filename, type=None, **kwargs):
      """
      Convert data written to BytesIO into the format expected by the Download component.
      :param src: array of bytes or a writer that can write to BytesIO
      :param filename: the name of the file
      :param type: type of the file (optional, passed to Blob in the javascript layer)
      :return: dict of data frame content (base64 encoded) and meta data used by the Download component
      """
      content = src if isinstance(src, bytes) else _io_to_str(io.BytesIO(), src, **kwargs)
      return dict(
          content=base64.b64encode(content).decode(),
          filename=filename,
          type=type,
          base64=True,
      )
  
  
  def send_string(src, filename, type=None, **kwargs):
      """
      Convert data written to StringIO into the format expected by the Download component.
      :param src: a string or a writer that can write to StringIO
      :param filename: the name of the file
      :param type: type of the file (optional, passed to Blob in the javascript layer)
      :return: dict of data frame content (NOT base64 encoded) and meta data used by the Download component
      """
      content = src if isinstance(src, str) else _io_to_str(io.StringIO(), src, **kwargs)
      return dict(content=content, filename=filename, type=type, base64=False)
  
  
  def _io_to_str(data_io, writer, **kwargs):
      # Some pandas writers try to close the IO, we do not want that.
      data_io_close = data_io.close
      data_io.close = lambda: None
      # Write data content.
      writer(data_io, **kwargs)
      data_value = data_io.getvalue()
      data_io_close()
      return data_value
  
  
  def send_data_frame(writer, filename, type=None, **kwargs):
      """
      Convert data frame into the format expected by the Download component.
      :param writer: a data frame writer
      :param filename: the name of the file
      :param type: type of the file (optional, passed to Blob in the javascript layer)
      :return: dict of data frame content (base64 encoded) and meta data used by the Download component
  
      Examples
      --------
  
      >>> df = pd.DataFrame({'a': [1, 2, 3, 4], 'b': [2, 1, 5, 6], 'c': ['x', 'x', 'y', 'y']})
      ...
      >>> send_data_frame(df.to_csv, "mydf.csv")  # download as csv
      >>> send_data_frame(df.to_json, "mydf.json")  # download as json
      >>> send_data_frame(df.to_excel, "mydf.xls", index=False) # download as excel
      >>> send_data_frame(df.to_pickle, "mydf.pkl") # download as pickle
  
      """
      name = writer.__name__
      # Check if the provided writer is known.
      if name not in _data_frame_senders.keys():
          raise ValueError(
              "The provided writer ({}) is not supported, "
              "try calling send_string or send_bytes directly.".format(name)
          )
      # Send data frame using the appropriate send function.
      return _data_frame_senders[name](writer, filename, type, **kwargs)
  
  
  _data_frame_senders = {
      "to_csv": send_string,
      "to_json": send_string,
      "to_html": send_string,
      "to_excel": send_bytes,
      "to_feather": send_bytes,
      "to_parquet": send_bytes,
      "to_msgpack": send_bytes,
      "to_stata": send_bytes,
      "to_pickle": send_bytes,
  }
  
  # endregion
  