SKLearn Pipeline w/ ColumnTransformer：'numpy.ndarray'对象没有属性'lower'

Question

我正在尝试使用SKLearn 0.20.2来制作管道，同时使用新的ColumnTransformer功能。我的问题是我不断收到错误：

AttributeError: 'numpy.ndarray' object has no attribute 'lower'

我有一列名为 text 的文本斑点。我所有其他列本质上都是数字。我正在尝试在我的管道中使用Countvectorizer，我认为这就是问题所在。将非常感谢这个。

from sklearn.impute import SimpleImputer
from sklearn.compose import ColumnTransformer
# plus other necessary modules
# mapped to column names from dataframe
numeric_features = ['hasDate', 'iterationCount', 'hasItemNumber', 'isEpic']
numeric_transformer = Pipeline(steps=[
    ('imputer', SimpleImputer(strategy='median'))
])
# mapped to column names from dataframe
text_features = ['text']
text_transformer = Pipeline(steps=[
    ('imputer', SimpleImputer(strategy='most_frequent”')),
    ('vect', CountVectorizer())
])
preprocessor = ColumnTransformer(
    transformers=[('num', numeric_transformer, numeric_features),('text', text_transformer, text_features)]
)
clf = Pipeline(steps=[('preprocessor', preprocessor),
                      ('classifier', MultinomialNB())
                     ])
x_train, x_test, y_train, y_test = train_test_split(features, labels, test_size=0.33)
clf.fit(x_train,y_train)

Answer 1

@SergeyBushmanov帮助我诊断了标题中的错误，这是由于对文本运行SimpleImputer引起的。

我还有一个错误，我将为此写一个新问题。