使用Scikit Learn的DictVectorizer时，toarray中的MemoryError

I am trying to implement the SelectKBest algorithm on my data to get the best features out of it. For this I am first preprocessing my data using DictVectorizer and the data consists of 1061427 rows with 15 features. Each feature has many different values and I believe I am getting a memory error due to high cardinality.I am trying to implement the SelectKBest algori