解释关于Kmean和SVM的代码+添加注释

以下一段代码是基于K-means和SVM的URL检测,分为正常访问,XSS攻击,目录遍历攻击以及SQL注入攻击,是我根据双分类的URL检测改的,有一定的注释,但想理解重要部分每一行的意思,特别是class Baseframe下Train函数,kmeans函数和transform函数每一行的作用。



```python
import os
import time
import urllib
import pickle
import numpy as np

from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.model_selection import train_test_split
from sklearn import svm
from sklearn.cluster import KMeans
from sklearn.linear_model import LogisticRegression

from scipy.sparse import csr_matrix, lil_matrix, coo_matrix


# kmeans聚合的维度
k = 80
# ngram系数
n = 2

# 是否使用kmeans
use_k = True

# 新定义输出方法,便于调试
def printT(word):
    a = time.strftime('%Y-%m-%d %H:%M:%S: ', time.localtime(time.time()))
    print(a + str(word))

da = []
da0 = []
da1 = []
da2 = []
da3 = []


with open("data/URL.txt", 'r', encoding='utf-8') as f:
    lines = f.readlines()
    for line in lines:
        line = line.strip()
        line = line.split('\t')
        da.append(line)


for i in range(len(da)):
    if da[i][1] == '0' :
        da0.append(da[i][0][:])
    if da[i][1] == '1' :
        da1.append(da[i][0][:])
    if da[i][1] == '2' :
        da2.append(da[i][0][:])
    if da[i][1] == '3' :
        da3.append(da[i][0][:])

print(type(da0))


# 训练模型基类
class Baseframe(object):

    def __init__(self):
        pass

    # 训练
    def Train(self):

        # 读取数据
        printT("Loading safe Data:")
        safe_list = da0

        printT("Loading xss Data:")
        xss_list = da1

        printT("Loading dta Data:")
        dta_list = da2

        printT("Loading sql Data:")
        sql_list = da3

        # 整合数据
        data = [safe_list, xss_list, dta_list, sql_list]
        # print(data[0])
        printT("Done, safe Numbers:" + str(len(data[0])) + " xss Numbers:" + str(len(data[1])) + " dta Numbers:" + str(len(data[2])) + " sql Numbers:" + str(len(data[3])))

        # 打标记
        safe_y = [0 for i in range(len(data[0]))]
        xss_y = [1 for i in range(len(data[1]))]
        dta_y = [2 for i in range(len(data[2]))]
        sql_y = [3 for i in range(len(data[3]))]

        y = safe_y + xss_y + dta_y + sql_y

        # 数据向量化预处理
        # 定义矢量化实例
        self.vectorizer = TfidfVectorizer(tokenizer=self.get_ngrams)
        # 把不规律的文本字符串列表转换成规律的([i,j],weight)的矩阵X[url条数,分词总类的总数,理论上少于256^n]
        # i表示第几条url,j对应于term编号(或者说是词片编号)
        X = self.vectorizer.fit_transform(data[0] + data[1] + data[2] + data[3])
        print(X)
        print(X.shape)
        printT("Data Dimentions: " + str(X.shape))

        # 通过kmeans降维
        if use_k:
            X = self.transform(self.kmeans(X))
            printT("Kmeans Succeed")

        printT("Devide Training Data")
        # 使用train_test_split分割X,y列表(testsize表示测试占的比例)(random为种子)
        # X_train矩阵的数目对应 y_train列表的数目(一一对应)  -->> 用来训练模型
        # X_test矩阵的数目对应(一一对应) -->> 用来测试模型的准确性
        X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)

        printT('Devide Succeed')
        printT('Begin Training:')
        printT(self.classifier)
        self.classifier.fit(X_train, y_train)

        # 使用测试值对模型的准确度进行计算
        printT(self.getname() + 'Model Accuracy:{}'.format(self.classifier.score(X_test, y_test)))

        # 保存训练结果
        with open('model/' + self.getname() + '.pickle', 'wb') as output:
            pickle.dump(self, output)

    # 数据预处理裁剪字符格式
    def get_ngrams(self, query):
        tempQuery = str(query)
        ngrams = []
        for i in range(0, len(tempQuery)-n):
            ngrams.append(tempQuery[i:i+n])
        return ngrams

    def kmeans(self, weight):
        printT('Matrix before kmeans: ' + str(weight.shape))
        weight = weight.tolil().transpose()
        # 同一组数据 同一个k值的聚类结果是一样的。保存结果避免重复运算
        try:
            with open('model/k' + str(k) + '.label', 'r') as input:
                printT('loading kmeans success')
                a = input.read().split(' ')

                self.label = [int(i) for i in a[:-1]]
        except FileNotFoundError:
            printT('Start Kmeans: ')

            clf = KMeans(n_clusters=k, precompute_distances=False)

            s = clf.fit(weight)
            printT(s)

            # 保存聚类的结果
            self.label = clf.labels_

            with open('model/k' + str(k) + '.label', 'w') as output:
                for i in self.label:
                    output.write(str(i) + ' ')
        printT('kmeans succeed,total: ' + str(k) + ' classes')
        return weight

    # 转换成聚类后结果输入转置后的矩阵返回转置好的矩阵
    def transform(self, weight):
        a = set()
        # 用coo存可以存储重复位置的元素
        row = []
        col = []
        data = []
        # i代表旧矩阵行号label[i]代表新矩阵的行号
        for i in range(len(self.label)):
            if self.label[i] in a:
                continue
            a.add(self.label[i])
            for j in range(i, len(self.label)):
                if self.label[j] == self.label[i]:
                    temp = weight[j].rows[0]
                    col += temp
                    temp = [self.label[i] for t in range(len(temp))]
                    row += temp
                    data += weight[j].data[0]

        newWeight = coo_matrix((data, (row, col)), shape=(k,weight.shape[1]))
        return newWeight.transpose()

    # 对新的请求列表进行预测
    def predict(self, new_queries):
        # try:
        #     with open('model/' + self.getname() + '.pickle', 'rb') as input:
        #         self = pickle.load(input)
        #     printT('loading ' + self.getname() + ' model success')
        # except FileNotFoundError:
        printT('start to train the ' + self.getname() + ' model')
        self.Train()
        printT('start predict:')
        # 解码
        new_queries = [urllib.parse.unquote(url) for url in new_queries]
        X_predict = self.vectorizer.transform(new_queries)

        if use_k:
            printT('Transform Data')
            X_predict = self.transform(X_predict.tolil().transpose())

        printT('Transform Succeed, Start Predicting:')
        res = self.classifier.predict(X_predict)
        printT('Predict Succeed, Total:' + str(len(res)))
        result = {}

        result[0] = []
        result[1] = []
        result[2] = []
        result[3] = []

        # 两个列表并入一个元组列表
        for q, r in zip(new_queries, res):
            result[r].append(q)

        printT('safe query: ' + str(len(result[0])))
        printT('xss query: ' + str(len(result[1])))
        printT('dta query: ' + str(len(result[2])))
        printT('sql query: ' + str(len(result[3])))


        return result


class SVM(Baseframe):

    def getname(self):
        if use_k:
            return 'SVM__n'+str(n)+'_k'+str(k)
        return 'SVM_n'+str(n)

    def __init__(self):
        # 定理逻辑回归方法模型
        self.classifier = svm.SVC()


引用chatgpt部分指引作答:
这段代码实现了基于K-means和SVM的URL检测,用于将URL进行分类,分为正常访问、XSS攻击、目录遍历攻击以及SQL注入攻击。

第1行定义了kmeans聚合的维度k。第2行定义了ngram系数n。第4行定义了是否使用kmeans的标志use_k。第6-12行定义了一个新的输出方法printT,用于调试。第14-21行读取了URL.txt文件中的数据并分别存储到da0、da1、da2和da3列表中。

第23-89行定义了一个基类Baseframe,实现了训练、分类等方法。其中,Train()方法首先将数据读取出来,并将其整合到data列表中,同时为每个样本打上标记。接下来使用TfidfVectorizer实例将数据进行向量化预处理,并使用kmeans算法将维度降为k。最后使用train_test_split分割数据,将其分为训练集和测试集,并使用SVM进行模型训练。最后,计算模型的准确度并输出。
添加注释后的代码:

# kmeans聚合的维度
k = 80
# ngram系数
n = 2
 
# 是否使用kmeans
use_k = True
 
# 新定义输出方法,便于调试
def printT(word):
    a = time.strftime('%Y-%m-%d %H:%M:%S: ', time.localtime(time.time()))
    print(a + str(word))
 
da = []
da0 = []
da1 = []
da2 = []
da3 = []
 
# 打开文件并逐行读取
with open("data/URL.txt", 'r', encoding='utf-8') as f:
    lines = f.readlines()
    # 将每一行数据处理为数组格式并存入总数组中
    for line in lines:
        line = line.strip()
        line = line.split('\t')
        da.append(line)
 
# 根据数据类别进行分类
for i in range(len(da)):
    if da[i][1] == '0' :
        da0.append(da[i][0][:])
    if da[i][1] == '1' :
        da1.append(da[i][0][:])
    if da[i][1] == '2' :
        da2.append(da[i][0][:])
    if da[i][1] == '3' :
        da3.append(da[i][0][:])
 
# 输出 da0 的数据类型
print(type(da0))
 
# 训练模型基类
class Baseframe(object):
 
    def __init__(self):
        pass
 
    # 训练
    def Train(self):
 
        # 读取数据
        printT("Loading safe Data:")
        # 分类为“安全”的 url 列表
        safe_list = da0
 
        printT("Loading xss Data:")
        # 分类为“跨站脚本攻击”的 url 列表
        xss_list = da1
 
        printT("Loading dta Data:")
        # 分类为“数据库攻击”的 url 列表
        dta_list = da2
 
        printT("Loading sql Data:")
        # 分类为“SQL注入”的 url 列表
        sql_list = da3
 
        # 整合数据
        data = [safe_list, xss_list, dta_list, sql_list]
        # print(data[0])
        # 输出各个分类的 url 数量
        printT("Done, safe Numbers:" + str(len(data[0])) + " xss Numbers:" + str(len(data[1])) + " dta Numbers:" + str(len(data[2])) + " sql Numbers:" + str(len(data[3])))
 
        # 打标记
        safe_y = [0 for i in range(len(data[0]))]
        xss_y = [1 for i in range(len(data[1]))]
        dta_y = [2 for i in range(len(data[2]))]
        sql_y = [3 for i in range(len(data[3]))]
 
        # 对标记后的数据进行合并
        y = safe_y + xss_y + dta_y + sql_y
 
        # 数据向量化预处理
        # 定义矢量化实例,使用 ngram 进行切分
        self.vectorizer = TfidfVectorizer(tokenizer=self.get_ngrams)
        # 把不规律的文本字符串列表转换成规律的([i,j],weight)的矩阵X[url条数,分词总类的总数,理论上少于256^n]
        # i表示第几条url,j对应于term编号(或者说是词片编号)
        X = self.vectorizer.fit_transform(data[0] + data[1] + data[2] + data[3])  # 将四个数据集合并后使用TF-IDF向量化
print(X)  # 打印X矩阵
print(X.shape)  # 打印X矩阵的形状
printT("Data Dimentions: " + str(X.shape))  # 打印X矩阵的形状

if use_k:  # 如果使用KMeans降维
    X = self.transform(self.kmeans(X))  # 调用kmeans函数进行降维并进行转换
    printT("Kmeans Succeed")  # 打印KMeans成功

printT("Devide Training Data")  # 打印分割训练数据
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)  # 使用train_test_split函数进行数据集分割

printT('Devide Succeed')  # 打印数据集分割成功
printT('Begin Training:')  # 打印开始训练
printT(self.classifier)  # 打印分类器
self.classifier.fit(X_train, y_train)  # 使用训练数据进行模型训练

printT(self.getname() + 'Model Accuracy:{}'.format(self.classifier.score(X_test, y_test)))  # 打印模型的准确度

with open('model/' + self.getname() + '.pickle', 'wb') as output:  # 将模型保存为pickle文件
    pickle.dump(self, output)

def get_ngrams(self, query):  # 数据预处理裁剪字符格式
    tempQuery = str(query)
    ngrams = []
    for i in range(0, len(tempQuery)-n):
        ngrams.append(tempQuery[i:i+n])
    return ngrams

def kmeans(self, weight):  # 对输入的矩阵进行KMeans聚类并进行降维
    printT('Matrix before kmeans: ' + str(weight.shape))  # 打印KMeans处理前矩阵的形状
    weight = weight.tolil().transpose()  # 将输入矩阵转化为LIL格式后转置
    try:
        with open('model/k' + str(k) + '.label', 'r') as input:  # 尝试打开保存的聚类结果
            printT('loading kmeans success')  # 打印成功加载聚类结果
            a = input.read().split(' ')
            self.label = [int(i) for i in a[:-1]]  # 将聚类结果转化为标签
    except FileNotFoundError:
        printT('Start Kmeans: ')  # 打印开始进行KMeans聚类
      clf = KMeans(n_clusters=k, precompute_distances=False)
# 创建k-means聚类器对象,设置簇的数量为k,不使用预计算距离
s = clf.fit(weight)
# 用权重weight训练聚类器clf,得到聚类模型s
printT(s)
# 输出聚类模型s的信息
 
# 保存聚类的结果
self.label = clf.labels_
# 将聚类的结果存储到类的label属性中
 
with open('model/k' + str(k) + '.label', 'w') as output:
    for i in self.label:
        output.write(str(i) + ' ')
# 将聚类的结果写入文件‘model/k'+str(k)+'.label’中

printT('kmeans succeed,total: ' + str(k) + ' classes')
# 输出聚类成功信息,总共聚为k类
return weight
# 返回权重weight
 
# 转换成聚类后结果输入转置后的矩阵返回转置好的矩阵
def transform(self, weight):
    a = set()
    # 创建空集合a用来存储出现过的聚类结果
    row = []
    col = []
    data = []
    # 创建空列表row,col,data用来存储转换后的矩阵元素信息
    for i in range(len(self.label)):
        if self.label[i] in a:
            continue
        a.add(self.label[i])
        # 如果聚类结果已经在a集合中出现过,跳过循环
        # 否则将聚类结果添加到a集合中
        for j in range(i, len(self.label)):
            if self.label[j] == self.label[i]:
                # 如果第j个元素的聚类结果和第i个元素相同
                temp = weight[j].rows[0]
                # 从weight的第j行中获取非零元素所在的列号
                col += temp
                temp = [self.label[i] for t in range(len(temp))]
                # 构建与temp相同长度的列表,每个元素为第i个元素的聚类结果
                row += temp
                # 将构建的列表添加到row列表中
                data += weight[j].data[0]
                # 从weight的第j行中获取非零元素的值并添加到data列表中
 
    newWeight = coo_matrix((data, (row, col)), shape=(k,weight.shape[1]))
    # 用row、col、data构建COO稀疏矩阵newWeight
    # 稀疏矩阵的行数为k,列数为weight矩阵的列数
    return newWeight.transpose()
    # 返回newWeight的转置矩阵

# 对新的请求列表进行预测
def predict(self, new_queries):
    # try:
    #     with open('model/' + self.getname() + '.pickle', 'rb') as input:
    #         self = pickle.load(input)
    #     printT('loading ' + self.getname() + ' model success')
    # except FileNotFoundError:
#打印训练模型的提示信息
printT('start to train the ' + self.getname() + ' model')

#调用自身的Train方法进行训练
self.Train()

#打印开始预测的提示信息
printT('start predict:')

#对输入的查询进行解码,将其中的%xx还原成原始字符
new_queries = [urllib.parse.unquote(url) for url in new_queries]

将解码后的查询转换为特征向量
X_predict = self.vectorizer.transform(new_queries)

if use_k:
# 对X_predict转置,以便处理特征
X_predict = self.transform(X_predict.tolil().transpose())

#打印特征转换成功的提示信息
printT('Transform Succeed, Start Predicting:')

#对输入的特征进行分类预测
res = self.classifier.predict(X_predict)

#打印预测成功并输出预测的结果总数
printT('Predict Succeed, Total:' + str(len(res)))

#创建一个字典,用于存储预测结果
result = {}

#分别为0、1、2、3四个类别创建一个空列表
result[0] = []
result[1] = []
result[2] = []
result[3] = []

#将每个查询的预测结果与其对应的查询并入一个元组,并将其添加到对应类别的列表中
for q, r in zip(new_queries, res):
result[r].append(q)

#打印每个类别的预测结果总数
printT('safe query: ' + str(len(result[0])))
printT('xss query: ' + str(len(result[1])))
printT('dta query: ' + str(len(result[2])))
printT('sql query: ' + str(len(result[3])))

#返回预测结果字典
return result

class SVM(Baseframe):
def getname(self):
    # 如果use_k为True,则返回SVM__n{n}_k{k}的字符串,否则返回SVM_n{n}的字符串
    if use_k:
        return 'SVM__n'+str(n)+'_k'+str(k)
    return 'SVM_n'+str(n)

def __init__(self):
    # 创建一个SVM分类器对象作为模型
    self.classifier = svm.SVC()

以下答案由GPT-3.5大模型与博主波罗歌共同编写:
该代码是一个基于K-means和SVM的URL检测器,可以将URL分为正常访问、XSS攻击、目录遍历攻击以及SQL注入攻击四类。下面逐行进行解释:

import os
import time
import urllib
import pickle
import numpy as np

from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.model_selection import train_test_split
from sklearn import svm
from sklearn.cluster import KMeans
from sklearn.linear_model import LogisticRegression

from scipy.sparse import csr_matrix, lil_matrix, coo_matrix

# kmeans聚合的维度
k = 80
# ngram系数
n = 2

# 是否使用kmeans
use_k = True

该部分定义了聚类维度k、ngram的系数n以及是否使用K-Means聚类来压缩数据维度,其中该代码在后续模型训练时使用K-Means对数据进行了降维。

# 新定义输出方法,便于调试
def printT(word):
    a = time.strftime('%Y-%m-%d %H:%M:%S: ', time.localtime(time.time()))
    print(a + str(word))

da = []
da0 = []
da1 = []
da2 = []
da3 = []

with open("data/URL.txt", 'r', encoding='utf-8') as f:
    lines = f.readlines()
    for line in lines:
        line = line.strip()
        line = line.split('\t')
        da.append(line)

#将da根据URL类型划分到不同的列表中
for i in range(len(da)):
    if da[i][1] == '0' :
        da0.append(da[i][0][:])
    if da[i][1] == '1' :
        da1.append(da[i][0][:])
    if da[i][1] == '2' :
        da2.append(da[i][0][:])
    if da[i][1] == '3' :
        da3.append(da[i][0][:])

该部分读取了一个包含URL和对应类型的txt文件,并将其划分到不同的列表中,分别对应不同的URL类型,用于后续的训练。

# 训练模型基类
class Baseframe(object):

    def __init__(self):
        pass

    # 训练
    def Train(self):

        # 读取数据
        printT("Loading safe Data:")
        safe_list = da0

        printT("Loading xss Data:")
        xss_list = da1

        printT("Loading dta Data:")
        dta_list = da2

        printT("Loading sql Data:")
        sql_list = da3

        # 整合数据
        data = [safe_list, xss_list, dta_list, sql_list]
        # print(data[0])
        printT("Done, safe Numbers:" + str(len(data[0])) + " xss Numbers:" + str(len(data[1])) + " dta Numbers:" + str(len(data[2])) + " sql Numbers:" + str(len(data[3])))

        # 打标记
        safe_y = [0 for i in range(len(data[0]))]
        xss_y = [1 for i in range(len(data[1]))]
        dta_y = [2 for i in range(len(data[2]))]
        sql_y = [3 for i in range(len(data[3]))]

        y = safe_y + xss_y + dta_y + sql_y

        # 数据向量化预处理
        # 定义矢量化实例

        self.vectorizer = TfidfVectorizer(tokenizer=self.get_ngrams)

        # 把不规律的文本字符串列表转换成规律的 ([i, j], weight) 的矩阵 X[url条数, 分词总类总数,理论上少于256^n]
        # i表示第几条url,j对应于term编号(或者说是词片编号)
        X = self.vectorizer.fit_transform(data[0] + data[1] + data[2] + data[3])

        # 通过kmeans降维
        if use_k:
            X = self.transform(self.kmeans(X))

        # 使用train_test_split分割X,y列表(testsize表示测试占的比例)(random为种子)
        X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)

        printT('Begin Training:')
        printT(self.classifier)

        # 训练模型
        self.classifier.fit(X_train, y_train)

        # 使用测试值对模型的准确度进行计算
        printT(self.getname() + ' Model Accuracy:{}'.format(self.classifier.score(X_test, y_test)))

        # 保存训练结果
        with open('model/' + self.getname() + '.pickle', 'wb') as output:
            pickle.dump(self, output)

    # 数据预处理裁剪字符格式
    def get_ngrams(self, query):
        tempQuery = str(query)
        ngrams = []
        for i in range(0, len(tempQuery)-n):
            ngrams.append(tempQuery[i:i+n])
        return ngrams

    def kmeans(self, weight):
        # kmeans聚类进行数据降维
        weight = weight.tolil().transpose()
        try:
            with open('model/k' + str(k) + '.label', 'r') as input:
                a = input.read().split(' ')
                self.label = [int(i) for i in a[:-1]]
        except FileNotFoundError:
            clf = KMeans(n_clusters=k, precompute_distances=False)
            s = clf.fit(weight)
            self.label = clf.labels_
            # 保存聚类的结果
            with open('model/k' + str(k) + '.label', 'w') as output:
                for i in self.label:
                    output.write(str(i) + ' ')
        return weight

    def transform(self, weight):
        # 对应于kmeans之后的结果,将权重重新聚合
        a = set()
        row = []
        col = []
        data = []
        for i in range(len(self.label)):
            if self.label[i] in a:
                continue
            a.add(self.label[i])
            for j in range(i, len(self.label)):
                if self.label[j] == self.label[i]:
                    temp = weight[j].rows[0]
                    col += temp
                    temp = [self.label[i] for t in range(len(temp))]
                    row += temp
                    data += weight[j].data[0]

        newWeight = coo_matrix((data, (row, col)), shape=(k,weight.shape[1]))
        return newWeight.transpose()

    def predict(self, new_queries):
        # 载入模型并对新请求进行预测
        self.Train()
        # 解码
        new_queries = [urllib.parse.unquote(url) for url in new_queries]
        X_predict = self.vectorizer.transform(new_queries)

        if use_k:
            X_predict = self.transform(X_predict.tolil().transpose())

        # 进行预测
        res = self.classifier.predict(X_predict)
        result = {}

        result[0] = []
        result[1] = []
        result[2] = []
        result[3] = []

        # 将预测结果写入字典
        for q, r in zip(new_queries, res):
            result[r].append(q)

        return result

    # 改函数需要在子类中重写,返回模型名称
    def getname(self):
        pass

该部分定义了训练模型的基类Baseframe,用于训练SVM模型,完成模型训练后,可以根据新的请求进行预测。

训练的主要过程如下:

(1)读取数据

(2)整合、打标记

(3)数据向量化预处理

(4)通过kmeans降
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