Python 3.x 交叉评分'；sn_jobs=-1参数在python 3.6中不起作用

我试图提高精确度并评估我的人工神经网络，但我遇到了一个问题，n_jobs=-1的cross_val_分数不起作用， 我在cpu上使用tensorflow，错误是：-

BrokenProcessPool:任务取消序列化失败。请确保 函数的参数都是可拾取的

import keras
from keras.models import Sequential
from keras.layers import Dense


from keras.wrappers.scikit_learn import KerasClassifier
from sklearn.model_selection import cross_val_score

def build_classifier():
    classifier = Sequential()
    classifier.add(Dense(6,  kernel_initializer='uniform', activation='relu', input_dim=11))
    classifier.add(Dense(6, kernel_initializer='uniform', activation='relu'))
    classifier.add(Dense(1, kernel_initializer='uniform', activation='sigmoid'))
    classifier.compile(optimizer='adam', loss='binary_crossentropy', metrics=['accuracy'])
    return classifier

classifier = KerasClassifier(build_fn = build_classifier, batch_size = 10, nb_epoch = 100)
accuracies = cross_val_score(estimator= classifier, X= x_train, y= y_train, cv = 10, n_jobs= 1)