code: def _get_range(book, range_, sheet):
      
  
      filename = None
      if isinstance(book, str):
          filename = book
          book = opxl.load_workbook(book, data_only=True)
      elif isinstance(book, opxl.Workbook):
          pass
      else:
          raise TypeError
  
      if _is_range_address(range_):
          sheet_names = [name.upper() for name in book.sheetnames]
          index = sheet_names.index(sheet.upper())
          data = book.worksheets[index][range_]
      else:
          data = _get_namedrange(book, range_, sheet)
          if data is None:
              raise ValueError(
                  "Named range '%s' not found in %s" % (range_, filename or book)
              )
  
      return data
docs: Return a range as nested dict of openpyxl cells.