使用带参数的dataframe中的apply返回错误

我有以下代码

def mean_vectorizer(words, dimention, diction):
  return np.array([np.mean([diction[w] for w in words if w in diction] or [np.zeros(dimention)], axis=0)])

data['vector'] = data.apply(lambda x: mean_vectorizer(x['words'], 100, diction), axis=1)

words diction

运行上述代码将返回以下错误:

Exception: Data must be 1-dimensional         

但是,如果我用下面的代码运行一行代码,它不会抱怨

words = data.iloc[0]['words']
np.array([np.mean([diction[w] for w in words if w in diction] or [np.zeros(dimention)], axis=0)])