def __huffman_helper(real: HuffmanTree) -> None:
"""Helper function for build_huffman trees where it basically goes through
the tree turning the internal nodes symbols to None"""
if not real.is_leaf and real is not None:
real.symbol = None
__huffman_helper(real.left)
__huffman_helper(real.right)
def __preorder_pls(tree: HuffmanTree, freq_dict: Dict[int, int],
ff: Dict[int, int]) -> None:
if tree.is_leaf and tree.symbol is not None:
tree.symbol = freq_dict[max(freq_dict.keys())]
freq_dict.pop(max(freq_dict.keys()))
else:
__preorder_pls(tree.left, freq_dict, ff)
__preorder_pls(tree.right, freq_dict, ff)
def _swap(tree: HuffmanTree, dic: Dict) -> None:
"""
Swaps the values.
"""
if tree.symbol:
if tree.symbol in dic:
tree.symbol = dic[tree.symbol]
else:
_swap(tree.left, dic)
_swap(tree.right, dic)
