code: def to_excel(self, path, na_rep='', engine=None, **kwargs):
          
          from pandas.io.excel import ExcelWriter
  
          if isinstance(path, str):
              writer = ExcelWriter(path, engine=engine)
          else:
              writer = path
          kwargs['na_rep'] = na_rep
  
          for item, df in self.iteritems():
              name = str(item)
              df.to_excel(writer, name, **kwargs)
          writer.save()
docs: Write each DataFrame in Panel to a separate excel sheet.
  
          Parameters
          ----------
          path : string or ExcelWriter object
              File path or existing ExcelWriter
          na_rep : string, default ''
              Missing data representation
          engine : string, default None
              write engine to use - you can also set this via the options
              ``io.excel.xlsx.writer``, ``io.excel.xls.writer``, and
              ``io.excel.xlsm.writer``.
  
          Other Parameters
          ----------------
          float_format : string, default None
              Format string for floating point numbers
          cols : sequence, optional
              Columns to write
          header : boolean or list of string, default True
              Write out column names. If a list of string is given it is
              assumed to be aliases for the column names
          index : boolean, default True
              Write row names (index)
          index_label : string or sequence, default None
              Column label for index column(s) if desired. If None is given, and
              `header` and `index` are True, then the index names are used. A
              sequence should be given if the DataFrame uses MultiIndex.
          startrow : upper left cell row to dump data frame
          startcol : upper left cell column to dump data frame
  
          Notes
          -----
          Keyword arguments (and na_rep) are passed to the ``to_excel`` method
          for each DataFrame written.