AttributeError：“ LogisticRegression”对象没有属性“ named_steps”

Question

nil

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AttributeError                            Traceback (most recent call last)
 in 
----> 1 vectorizer = grid.best_estimator_.named_steps["tfidfvectorizer"]
      2 # transform the training dataset
      3 X_train = vectorizer.transform(text_train)
...

AttributeError: 'LogisticRegression' object has no attribute 'named_steps'

named_steps的替代品是什么？