如何获得模型的训练和验证准确性？

Question

我正在尝试获取训练和验证准确性值，但它没有返回acc和val_acc值。

model.compile(loss = 'sparse_categorical_crossentropy',
              optimizer = 'RMSprop',
              lr = 0.001,
              metrices = ['accuracy'])

# prepare the generators
train_gen = train_datagen.flow(training_images, 
                               training_labels,
                               batch_size = 64
                              )

validation_gen = validation_datagen.flow(testing_images, 
                               testing_labels,
                               batch_size = 64
                              )
    
# Train the Model
history = model.fit_generator(train_gen,
                              epochs = 20,
                              validation_data = validation_gen
                      )