code: def _rsplit(expr, pat=None, n=-1):
      
  
      return _string_op(expr, RSplit, output_type=types.List(types.string),
                        _pat=pat, _n=n)
docs: Split each string in the Series/Index by the given delimiter string,
      starting at the end of the string and working to the front.
      Equivalent to str.rsplit().
  
      :param expr:
      :param pat: Separator to split on. If None, splits on whitespace
      :param n: None, 0 and -1 will be interpreted as return all splits
      :return: sequence or scalar