写一段python代码实现文档之间查重需要

先进行文本预处理，包括去除停用词、特殊符号、数字等，对文本进行分词并进行词性标注和去除标点符号。然后利用TF-IDF算法计算文本相似度，通过设置阈值来判断两篇文档是否相似。具体实现代码如下：

import jieba
import jieba.analyse
import jieba.posseg as pseg
import math

def preprocess(text):
    """
    对文本进行预处理，包括去除停用词、特殊符号、数字等
    """
    # 去除特殊符号和数字
    text = re.sub('[^\\u4e00-\\u9fa5a-zA-Z]', '', text)
    # 分词并去除停用词
    words = [w.word for w in pseg.cut(text) if w.flag[0] not in ['x', 'u', 'w'] and w.word not in stopwords]
    return words

def get_tf(words):
    """
    计算单词的词频
    """
    tf = {}
    for word in words:
        if word not in tf:
            tf[word] = 0
        tf[word] += 1
    return tf

def get_idf(words, idf_dict):
    """
    计算单词的逆文档频率
    """
    idf = {}
    for word in words:
        if word not in idf:
            idf[word] = math.log(len(idf_dict) / (idf_dict.get(word, 0) + 1))
    return idf

def get_tfidf(tf, idf):
    """
    计算单词的TF-IDF值
    """
    tfidf = {}
    for word in tf:
        tfidf[word] = tf[word] * idf[word]
    return tfidf

def get_similarity(tfidf1, tfidf2):
    """
    计算两个文档的相似度
    """
    numerator = 0
    denominator1 = 0
    denominator2 = 0
    for word in tfidf1:
        numerator += tfidf1[word] * tfidf2.get(word, 0)
        denominator1 += tfidf1[word] ** 2
    for word in tfidf2:
        denominator2 += tfidf2[word] ** 2
    denominator = math.sqrt(denominator1) * math.sqrt(denominator2)
    if denominator == 0:
        return 0
    else:
        return numerator / denominator

def is_duplicate(text1, text2, threshold=0.8):
    """
    判断两篇文档是否相似
    """
    words1 = preprocess(text1)
    words2 = preprocess(text2)
    tf1 = get_tf(words1)
    tf2 = get_tf(words2)
    idf_dict = dict.fromkeys(set(words1 + words2), 0)
    idf_dict.update(get_idf(words1, idf_dict))
    idf_dict.update(get_idf(words2, idf_dict))
    tfidf1 = get_tfidf(tf1, idf_dict)
    tfidf2 = get_tfidf(tf2, idf_dict)
    similarity = get_similarity(tfidf1, tfidf2)
    if similarity >= threshold:
        return True
    else:
        return False

调用该函数可以判断两篇文档是否相似，例如：

text1 = "这是一篇测试文档，用于测试相似度计算。"
text2 = "这篇文档是用来测试相似度计算的。"
if is_duplicate(text1, text2):
    print("两篇文档相似")
else:
    print("两篇文档不相似")