code: def tuplize(nested):
    
    if isinstance(nested, str):
      return nested
    try:
      return tuple(map(tuplize, nested))
    except TypeError:
      return nested
docs: Recursively converts iterables into tuples.
  
    Args:
      nested: A nested structure of items and iterables.
  
    Returns:
      A nested structure of items and tuples.