python基于字典分词算法－逆向最大匹配算法

教程

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别小看任何人，越不起眼的人，往往会做些让人想不到的事。

逆向最大匹配算法是一种分词方法，它从待分词语句的末尾开始匹配，每次匹配最长的词语。其算法核心思想是从指定的字典文件中加载词汇，并对给定的句子进行分词处理。以下给出一个python代码示例

def load_dictionary(dict_path):
    """加载字典"""
    with open(dict_path, 'r', encoding='utf-8') as f:
        dictionary = set(f.readline().strip().split(' ')[0] for line in f)
    return dictionary

def reverse_maximum_matching(sentence, dictionary, max_word_length):
    """逆向最大匹配算法"""
    result = []
    index = len(sentence)
    while index > 0:
        word = None
        for size in range(max_word_length, 0, -1):
            if index - size < 0:
                continue
            candidate = sentence[index - size:index]
            if candidate in dictionary:
                word = candidate
                result.append(word)
                index -= size
                break
        if word is None:
            index -= 1
            result.append(sentence[index])
    result.reverse()
    return result

if __name__ == "__main__":
    # 指定字典文件路径
    dict_path = r"C:\Users\admin\PycharmProjects\pythonProject5\字典.txt"
    # 加载字典
    dictionary = load_dictionary(dict_path)
    # 待分词句子
    sentence = "咸鱼博客是一个忠于原创，乐于分享的独立博客网站"
    # 假设最长词语长度为5
    max_word_length = 5
    # 进行分词
    segmented_sentence = reverse_maximum_matching(sentence, dictionary, max_word_length)
    # 输出分词结果
    print("分词结果：", "/ ".join(segmented_sentence))