python哈夫曼编码代码

以下是Python实现哈夫曼编码的代码：

import heapq
from collections import defaultdict

def encode(symb2freq):
    heap = [[wt, [sym, ""]] for sym, wt in symb2freq.items()]
    heapq.heapify(heap)
    while len(heap) > 1:
        lo = heapq.heappop(heap)
        hi = heapq.heappop(heap)
        for pair in lo[1:]:
            pair[1] = '0' + pair[1]
        for pair in hi[1:]:
            pair[1] = '1' + pair[1]
        heapq.heappush(heap, [lo[0] + hi[0]] + lo[1:] + hi[1:])
    return sorted(heapq.heappop(heap)[1:], key=lambda p: (len(p[-1]), p))

txt = "hello world"
symb2freq = defaultdict(int)
for ch in txt:
    symb2freq[ch] += 1
huff = encode(symb2freq)
print("Symbol\tWeight\tHuffman Code")
for p in huff:
    print("%s\t%s\t%s" % (p[0], symb2freq[p[0]], p[1]))

这段代码实现了哈夫曼编码的基本功能，包括构建哈夫曼树、生成哈夫曼编码等。在这个例子中，我们使用了一个字符串“hello world”作为输入，然后统计每个字符出现的频率，最后生成对应的哈夫曼编码。