Python 你能在scikit学习中添加计数向量器吗?
我想基于文本语料库在中创建CountVectorizer,然后稍后向CountVectorizer添加更多文本(添加到原始词典) 如果我使用Python 你能在scikit学习中添加计数向量器吗?,python,nlp,scikit-learn,Python,Nlp,Scikit Learn,我想基于文本语料库在中创建CountVectorizer,然后稍后向CountVectorizer添加更多文本(添加到原始词典) 如果我使用transform(),它会保留原来的词汇表,但不会添加新词。如果我使用fit\u transform(),它只是从头开始重新生成词汇表。见下文: In [2]: count_vect = CountVectorizer() In [3]: count_vect.fit_transform(["This is a test"]) Out[3]: <
transform()
,它会保留原来的词汇表,但不会添加新词。如果我使用fit\u transform()
,它只是从头开始重新生成词汇表。见下文:
In [2]: count_vect = CountVectorizer()
In [3]: count_vect.fit_transform(["This is a test"])
Out[3]:
<1x3 sparse matrix of type '<type 'numpy.int64'>'
with 3 stored elements in Compressed Sparse Row format>
In [4]: count_vect.vocabulary_
Out[4]: {u'is': 0, u'test': 1, u'this': 2}
In [5]: count_vect.transform(["This not is a test"])
Out[5]:
<1x3 sparse matrix of type '<type 'numpy.int64'>'
with 3 stored elements in Compressed Sparse Row format>
In [6]: count_vect.vocabulary_
Out[6]: {u'is': 0, u'test': 1, u'this': 2}
In [7]: count_vect.fit_transform(["This not is a test"])
Out[7]:
<1x4 sparse matrix of type '<type 'numpy.int64'>'
with 4 stored elements in Compressed Sparse Row format>
In [8]: count_vect.vocabulary_
Out[8]: {u'is': 0, u'not': 1, u'test': 2, u'this': 3}
有什么方法可以做到这一点吗?在
scikit learn
中实现的算法被设计为一次适应所有数据,这对于大多数ML算法来说是必要的(尽管您描述的应用程序并不有趣),因此没有更新功能
但是,有一种方法可以通过稍微不同的方式来实现您想要的,请参见下面的代码
from sklearn.feature_extraction.text import TfidfVectorizer, CountVectorizer
count_vect = CountVectorizer()
count_vect.fit_transform(["This is a test"])
print count_vect.vocabulary_
count_vect.fit_transform(["This is a test", "This is not a test"])
print count_vect.vocabulary_
哪个输出
{u'this': 2, u'test': 1, u'is': 0}
{u'this': 3, u'test': 2, u'is': 0, u'not': 1}
{u'this': 2, u'test': 1, u'is': 0}
{u'this': 3, u'test': 2, u'is': 0, u'not': 1}