Day05【实现字符串的正向最大匹配】

目标

给定已知字符串和相关的词表集合，实现该字符串的正向最大匹配算法。

待切分字符串

#待切分文本
sentence = "经常有意见分歧"

对应的词表

#词典；每个词后方存储的是其词频，词频仅为示例，不会用到，也可自行修改
Dict = {"经常":0.1,
        "经":0.05,
        "有":0.1,
        "常":0.001,
        "有意见":0.1,
        "歧":0.001,
        "意见":0.2,
        "分歧":0.2,
        "见":0.05,
        "意":0.05,
        "见分歧":0.05,
        "分":0.1}

要求切分结果

#目标输出
target = ['经常', '有意见', '分歧']

实现

# 实现正向最大匹配
def forward_match(sentence, Dict):
    maxLength = 0
    vacab = []
    for str, pro in Dict.items():
        vacab.append(str)
        if len(str) > maxLength:
            maxLength = len(str)
    curlist = []
    while len(sentence) > 0:
        end = min(maxLength + 1, len(sentence) + 1)
        for j in reversed(range(0, end)):
            word = sentence[0:j]
            if word in vacab:
                curlist.append(word)
                sentence = sentence[j:]
                break
    return curlist

测试结果

if __name__=="__main__":
    match = forward_match(sentence, Dict)
    print(match)

运行结果：

[‘经常’, ‘有意见’, ‘分歧’]