python - scikit-learn 的逻辑回归在打印输出时给出关键错误

Question

我正在尝试使用逻辑回归将邮件分类为“垃圾邮件”或“火腿邮件”。我使用的数据源来自http://archive.ics.uci.edu/ ml/datasets/SMS+Spam+Collection 我发现 TFIDF 是从文本中获取特征的正确方法，因此我使用了 scikit learn 中的 TfidfVectorizer，这是我的代码:

msg_df = pd.read_csv('data/sms', delimiter='\t', header = None)

X_train_data, X_test_data, y_train_data, y_test_data = train_test_split(msg_df[1],msg_df[0])

sms_vectorizer = TfidfVectorizer()
X_train_vector = sms_vectorizer.fit_transform(X_train_data)
X_test_vector = sms_vectorizer.transform(X_test_data)

classifier = LogisticRegression()
classifier.fit(X_train_vector, y_train_data)

sms_predictions = classifier.predict(X_test_vector)

print sms_predictions
for i, prediction in enumerate(sms_predictions[:5]):
    print 'Prediction: %s. Message: %s' % (prediction, X_test_data[i])

当我运行代码时，出现以下错误:

KeyError                                  Traceback (most recent call last)
<ipython-input-19-b5f57158f320> in <module>()
      4 print sms_predictions
      5 for i, prediction in enumerate(sms_predictions[:5]):
----> 6     print 'Prediction: %s. Message: %s' % (prediction, X_test_data[i])

/usr/local/lib/python2.7/dist-packages/pandas/core/series.pyc in __getitem__(self, key)
    555     def __getitem__(self, key):
    556         try:
--> 557             result = self.index.get_value(self, key)
    558 
    559             if not np.isscalar(result):

/usr/local/lib/python2.7/dist-packages/pandas/core/index.pyc in get_value(self, series, key)
   1788 
   1789         try:
-> 1790             return self._engine.get_value(s, k)
   1791         except KeyError as e1:
   1792             if len(self) > 0 and self.inferred_type in ['integer','boolean']:

/usr/local/lib/python2.7/dist-packages/pandas/index.so in pandas.index.IndexEngine.get_value (pandas/index.c:3204)()

/usr/local/lib/python2.7/dist-packages/pandas/index.so in pandas.index.IndexEngine.get_value (pandas/index.c:2903)()

/usr/local/lib/python2.7/dist-packages/pandas/index.so in pandas.index.IndexEngine.get_loc (pandas/index.c:3843)()

/usr/local/lib/python2.7/dist-packages/pandas/hashtable.so in pandas.hashtable.Int64HashTable.get_item (pandas/hashtable.c:6525)()

/usr/local/lib/python2.7/dist-packages/pandas/hashtable.so in pandas.hashtable.Int64HashTable.get_item (pandas/hashtable.c:6463)()

KeyError: 0

Answer 1

从这里开始:

print sms_predictions
for i, prediction in enumerate(sms_predictions[:5]):
    print i,  prediction
    #print 'Prediction: %s. Message: %s' % (prediction, X_test_data[i])