import pandas,numpy,os,nltk,langid
from sklearn.feature_extraction.text import TfidfTransformer
from sklearn.feature_extraction.text import CountVectorizer
from sklearn.naive_bayes import MultinomialNB
#preprocess用于将一个文本文档进行切词,并以字符串形式输出切词结果
def preprocess(path_name):
text_with_spaces=""
textfile=open(path_name,"r",encoding="utf-8").read()
textcut=nltk.word_tokenize(textfile)
for word in textcut:
text_with_spaces+=word+" "
return text_with_spaces
#loadtrainset用于将某一文件夹下的所有文本文档批量切词后,载入为训练数据集;返回训练集和每一个文本(元组)对应的类标号。
def loadtrainset(path,classtag):
allfiles=os.listdir(path)
processed_textset=[]
allclasstags=[]
for thisfile in allfiles:
path_name=path+"/"+thisfile
processed_textset.append(preprocess(path_name))
allclasstags.append(classtag)
return processed_textset,allclasstags
def train():
processed_textdata1,class1=loadtrainset("data/CS", "CS")
processed_textdata2,class2=loadtrainset("data/CL", "CL")
integrated_train_data=processed_textdata1+processed_textdata2
classtags_list=class1+class2
count_vector = CountVectorizer()
#该类会将文本中的词语转换为词频矩阵,矩阵元素a[i][j] 表示j词在i类文本下的词频
vector_matrix = count_vector.fit_transform(integrated_train_data)
#tfidf度量模型
train_tfidf = TfidfTransformer(use_idf=False).fit_transform(vector_matrix)
#将词频矩阵转化为权重矩阵,每一个特征值就是一个单词的TF-IDF值
#调用MultinomialNB分类器进行训练
clf = MultinomialNB().fit(train_tfidf,classtags_list)#
return count_vector,clf
def isCyber(content):
#[CL,CS]
content_lang = langid.classify(content)[0]
if content_lang == 'en':
text_with_spaces=""
textcut=nltk.word_tokenize(content)
for word in textcut:
text_with_spaces+=word+" "
testset=[]
testset.append(text_with_spaces)
count_vector,clf = train()
new_count_vector = count_vector.transform(testset)
new_tfidf= TfidfTransformer(use_idf=False).fit_transform(new_count_vector)
predict_result = clf.predict(new_tfidf) #预测结果
print(predict_result)
print( clf.predict_proba(new_tfidf) )
print( clf.predict_proba(new_tfidf)[0][1] )
if predict_result[0] == 'CS':
if clf.predict_proba(new_tfidf)[0][1] >= 0.7:
return True
return False
if content_lang == 'zh':
print()
if __name__=='__main__':
content = '''These pandemic days flow by in waves of exhilaration and stillness. Who knew a trip to the grocery store could be so exciting? Bread-and-milk runs have become surgical raids: Sterilize the grocery cart with a disinfectant wipe, scout out the TP aisle, exchange sideways glances with the could-be infected, grab the essentials, and get the hell out of there. Later, as another news alert interrupts the Netflix stream, the group text explodes: “This is crazy,” everyone says from their respective couches. Few hasten to add that crazy is also sort of fun.'''
isCyber(content)