nltk naivebayes分类器，用于文本分类

在下面的代码中，我知道我的naivebayes分类器正确运行，因为它在trainset1上正确运行，但是为什么它不能在trainset2上运行？我什至在两个分类器上尝试过，一个来自TextBlob，另一个直接来自nltk。

from textblob.classifiers import NaiveBayesClassifier
from textblob import TextBlob
from nltk.tokenize import word_tokenize
import nltk

trainset1 = [('I love this sandwich.', 'pos'),
('This is an amazing place!', 'pos'),
('I feel very good about these beers.', 'pos'),
('This is my best work.', 'pos'),
("What an awesome view", 'pos'),
('I do not like this restaurant', 'neg'),
('I am tired of this stuff.', 'neg'),
("I can't deal with this", 'neg'),
('He is my sworn enemy!', 'neg'),
('My boss is horrible.', 'neg')]

trainset2 = [('hide all brazil and everything plan limps to anniversary inflation plan initiallyis limping its first anniversary amid soaring prices', 'class1'),
         ('hello i was there and no one came', 'class2'),
         ('all negative terms like sad angry etc', 'class2')]

def nltk_naivebayes(trainset, test_sentence):
    all_words = set(word.lower() for passage in trainset for word in word_tokenize(passage[0]))
    t = [({word: (word in word_tokenize(x[0])) for word in all_words}, x[1]) for x in trainset]
    classifier = nltk.NaiveBayesClassifier.train(t)
    test_sent_features = {word.lower(): (word in word_tokenize(test_sentence.lower())) for word in all_words}
    return classifier.classify(test_sent_features)

def textblob_naivebayes(trainset, test_sentence):
    cl = NaiveBayesClassifier(trainset)
    blob = TextBlob(test_sentence,classifier=cl)
    return blob.classify() 

test_sentence1 = "he is my horrible enemy"
test_sentence2 = "inflation soaring limps to anniversary"

print nltk_naivebayes(trainset1, test_sentence1)
print nltk_naivebayes(trainset2, test_sentence2)
print textblob_naivebayes(trainset1, test_sentence1)
print textblob_naivebayes(trainset2, test_sentence2)

输出：

neg
class2
neg
class2

尽管test_sentence2显然属于class1。