如何遍历霍夫曼树(通过代码)并打印出每个字母的编码？

# 定义霍夫曼树节点类
class HuffmanNode:
    def __init__(self, char, freq):
        self.char = char  # 字符
        self.freq = freq  # 字符出现频率
        self.left = None  # 左子节点
        self.right = None  # 右子节点

# 构建霍夫曼树
def build_huffman_tree(freq_dict):
    nodes = []
    for char, freq in freq_dict.items():
        nodes.append(HuffmanNode(char, freq))
    
    while len(nodes) > 1:
        nodes = sorted(nodes, key=lambda x: x.freq)
        left_node = nodes.pop(0)
        right_node = nodes.pop(0)
        parent_node = HuffmanNode(None, left_node.freq + right_node.freq)
        parent_node.left = left_node
        parent_node.right = right_node
        nodes.append(parent_node)
    
    return nodes[0]

# 遍历霍夫曼树并打印编码
def traverse_huffman_tree(node, code=''):
    if node.char:
        print(f"Character: {node.char}, Code: {code}")
    else:
        traverse_huffman_tree(node.left, code + '0')
        traverse_huffman_tree(node.right, code + '1')

# 示例数据
freq_dict = {'A': 5, 'B': 9, 'C': 12, 'D': 13, 'E': 16, 'F': 45}

# 构建霍夫曼树
huffman_tree = build_huffman_tree(freq_dict)

# 遍历霍夫曼树并打印编码
traverse_huffman_tree(huffman_tree)