我正在用NLTK实现朴素贝叶斯分类器。但当我用提取的特征训练分类器时,它会给出错误“太多的值无法解包”。我只是python的初学者。这是密码。程序正在从文件中读取文本并从这些文件中提取特征。在
import nltk.classify.util,os,sys;
from nltk.classify import NaiveBayesClassifier;
from nltk.corpus import stopwords;
from nltk.tokenize import word_tokenize,RegexpTokenizer;
import re;
TAG_RE = re.compile(r'<[^>]+>')
def remove_tags(text):
return TAG_RE.sub('', text)
def word_feats(words):
return dict([(word,True) for word in words])
def feature_extractor(sentiment):
path = "train/"+sentiment+"/"
files = os.listdir(path);
feats = {};
i = 0;
for file in files:
f = open(path+file,"r", encoding='utf-8');
review = f.read();
review = remove_tags(review);
stopWords = (stopwords.words("english"))
tokenizer = RegexpTokenizer(r"\w+");
tokens = tokenizer.tokenize(review);
features = word_feats(tokens);
feats.update(features)
return feats;
posative_feat = feature_extractor("pos");
p = open("posFeat.txt","w", encoding='utf-8');
p.write(str(posative_feat));
negative_feat = feature_extractor("neg");
n = open("negFeat.txt","w", encoding='utf-8');
n.write(str(negative_feat));
plength = int(len(posative_feat)*3/4);
nlength = int(len(negative_feat)*3/4)
totalLength = plength+nlength;
trainFeatList = {}
testFeatList = {}
i = 0
for items in posative_feat.items():
i +=1;
value = {items[0]:items[1]}
if(i<plength):
trainFeatList.update(value);
else:
testFeatList.update(value);
j = 0
for items in negative_feat.items():
j +=1;
value = {items[0]:items[1]}
if(j<plength):
trainFeatList.update(value);
else:
testFeatList.update(value);
classifier = NaiveBayesClassifier.train(trainFeatList)
print(nltk.classify.util.accuracy(classifier,testFeatList));
classifier.show_most_informative_features();
看一下NLTK页面http://www.nltk.org/book/ch06.html,似乎给}类型,而传递给分类器的数据是
NaiveBayesClassifier
的数据属于{list(dict)
类型。在如果以类似的方式表示数据,则会得到不同的结果。基本上,它是一个
(feature dict, label)
的列表。在代码中有多个错误:
True
布尔值在第12行似乎没有作用trainFeatList
和{value
应该是tuple(dict,str)
NaiveBayesClassifier
,以及classifier
的任何使用从负特性循环中取出如果您修复了前面的错误,分类器就可以工作了,但是除非我知道您要实现什么,否则会令人困惑,并且无法很好地预测。在
您需要注意的主线是当您为变量
value
赋值时。在例如:
应该是这样的:
^{pr2}$然后,您将调用列表中的
.append()
来添加每个值,而不是.update()
。在您可以在http://pastebin.com/91Zu59Cm上查看更新后的代码在错误工作状态下的示例,但我建议您考虑以下几点:
NaiveBayesClassifier
类的数据?在相关问题 更多 >
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