不明白这个 TypeError: 'NoneType' object is not subscriptable 错误

Question

我有以下课程：

class TfidfEmbeddingVectorizer(object):
    def __init__(self, word2vec):
        self.word2vec = word2vec
        self.word2weight = None
        self.dim = len(word2vec[next(iter(w2v))])

    def fit(self, X, y):
        tfidf = TfidfVectorizer(analyzer=lambda x: x)
        tfidf.fit(X)
        # if a word was never seen - it must be at least as infrequent
        # as any of the known words - so the default idf is the max of
        # known idf's
        max_idf = max(tfidf.idf_)
        self.word2weight = defaultdict(
            lambda: max_idf,
            [(w, tfidf.idf_[i]) for w, i in tfidf.vocabulary_.items()])

        return self

    def transform(self, X):
        return np.array([
                np.mean([self.word2vec[w] * self.word2weight[w]
                         for w in words if w in self.word2vec] or
                        [np.zeros(self.dim)], axis=0)
                for words in X
            ])

但是当我实例化它时，我得到以下错误：

File "<ipython-input-70-dcde03597dd3>", line 23, in <listcomp>
for w in words if w in self.word2vec] or
TypeError: 'NoneType' object is not subscriptable

Answer 1

好吧，当您收到TypeError: 'NoneType' object is not subscriptable 错误时，您正在尝试执行None[0] 之类的操作。

你的问题就在这里：

self.word2weight = None

然后你试图在这里访问它：

np.mean([self.word2vec[w] * self.word2weight[w]

也许你需要先调用函数fit，它写入word2weight