code: def to_csv(self, encoding=export.ENCODING, dialect=export.DIALECT,
                 make_filename=export.MAKE_FILENAME):
          
          for s in self._sheets:
              s.to_csv(None, encoding, dialect, make_filename)
docs: Dump all worksheets of the spreadsheet to individual CSV files.
  
          Args:
              encoding (str): result string encoding
              dialect (str): :mod:`csv` dialect name or object to use
              make_filename: template or one-argument callable returning the filename
  
          If ``make_filename`` is a string, it is string-interpolated with an
          infos-dictionary with the fields ``id`` (spreadhseet id), ``title``
          (spreadsheet title), ``sheet`` (worksheet title), ``gid`` (worksheet
          id), ``index`` (worksheet index), and ``dialect`` CSV dialect to
          generate the filename: ``filename = make_filename % infos``.
  
          If ``make_filename`` is a callable, it will be called with the
          infos-dictionary to generate the filename:
          ``filename = make_filename(infos)``.