python - 使用 countVectorizer 在 python 中计算我自己词汇的单词出现次数

Question

Doc1: ['And that was the fallacy. Once I was free to talk with staff members']

Doc2: ['In the new, stripped-down, every-job-counts business climate, these human']

Doc3 : ['Another reality makes emotional intelligence ever more crucial']

Doc4: ['The globalization of the workforce puts a particular premium on emotional']

Doc5: ['As business changes, so do the traits needed to excel. Data tracking']

这是我的词汇示例:

my_vocabulary= [‘was the fallacy’, ‘free to’, ‘stripped-down’, ‘ever more’, ‘of the workforce’, ‘the traits needed’]

关键是我词汇表中的每个单词都是二元词或三元词。我的词汇包括我的文档集中所有可能的二元词和三元词，我只是在这里给了你一个样本。根据应用程序，这就是我的词汇应该是怎样的。我正在尝试使用 countVectorizer 如下:

from sklearn.feature_extraction.text import CountVectorizer
doc_set = [Doc1, Doc2, Doc3, Doc4, Doc5]
vectorizer = CountVectorizer( vocabulary=my_vocabulary)
tf = vectorizer.fit_transform(doc_set) 

我期待得到这样的东西:

print tf:
(0, 126)    1
(0, 6804)   1
(0, 5619)   1
(0, 5019)   2
(0, 5012)   1
(0, 999)    1
(0, 996)    1
(0, 4756)   4

其中第一列是文档 ID，第二列是词汇表中的词 ID，第三列是该词在该文档中的出现次数。但是 tf 是空的。我知道在一天结束时，我可以编写一个代码来遍历词汇表中的所有单词并计算出现次数并制作矩阵，但是我可以将 countVectorizer 用于我拥有的这个输入并节省时间吗？我在这里做错了吗？如果 countVectorizer 不是正确的方法，任何建议将不胜感激。

Answer 1

您可以通过在 CountVectorizer 中指定 ngram_range 参数来构建所有可能的二元词组和三元词组的词汇表。在 fit_tranform 之后，您可以使用 get_feature_names() 和 toarray() 方法查看词汇和频率。后者为每个文档返回一个频率矩阵。更多信息:http://scikit-learn.org/stable/modules/feature_extraction.html#text-feature-extraction

from sklearn.feature_extraction.text import CountVectorizer

Doc1 = 'And that was the fallacy. Once I was free to talk with staff members'
Doc2 = 'In the new, stripped-down, every-job-counts business climate, these human'
Doc3 = 'Another reality makes emotional intelligence ever more crucial'
Doc4 = 'The globalization of the workforce puts a particular premium on emotional'
Doc5 = 'As business changes, so do the traits needed to excel. Data tracking'
doc_set = [Doc1, Doc2, Doc3, Doc4, Doc5]

vectorizer = CountVectorizer(ngram_range=(2, 3))
tf = vectorizer.fit_transform(doc_set)
vectorizer.vocabulary_
vectorizer.get_feature_names()
tf.toarray()

至于您尝试做的事情，如果您在词汇表上训练 CountVectorizer 然后转换文档，它会起作用。

my_vocabulary= ['was the fallacy', 'more crucial', 'particular premium', 'to excel', 'data tracking', 'another reality']

vectorizer = CountVectorizer(ngram_range=(2, 3))
vectorizer.fit_transform(my_vocabulary)
tf = vectorizer.transform(doc_set)

vectorizer.vocabulary_
Out[26]: 
{'another reality': 0,
 'data tracking': 1,
 'more crucial': 2,
 'particular premium': 3,
 'the fallacy': 4,
 'to excel': 5,
 'was the': 6,
 'was the fallacy': 7}

tf.toarray()
Out[25]: 
array([[0, 0, 0, 0, 1, 0, 1, 1],
       [0, 0, 0, 0, 0, 0, 0, 0],
       [1, 0, 1, 0, 0, 0, 0, 0],
       [0, 0, 0, 1, 0, 0, 0, 0],
       [0, 1, 0, 0, 0, 1, 0, 0]], dtype=int64)