python - KeyError : '' val_loss"when training model

Question

我正在用keras训练模型，并且在fit_generator函数的回调中遇到错误。我总是跑到纪元3rd并收到此错误

annotation_path = 'train2.txt'
    log_dir = 'logs/000/'
    classes_path = 'model_data/deplao_classes.txt'
    anchors_path = 'model_data/yolo_anchors.txt'
    class_names = get_classes(classes_path)
    num_classes = len(class_names)
    anchors = get_anchors(anchors_path)

    input_shape = (416,416) # multiple of 32, hw

    is_tiny_version = len(anchors)==6 # default setting
    if is_tiny_version:
        model = create_tiny_model(input_shape, anchors, num_classes,
            freeze_body=2, weights_path='model_data/tiny_yolo_weights.h5')
    else:
        model = create_model(input_shape, anchors, num_classes,
            freeze_body=2, weights_path='model_data/yolo_weights.h5') # make sure you know what you freeze

    logging = TensorBoard(log_dir=log_dir)
    checkpoint = ModelCheckpoint(log_dir + 'ep{epoch:03d}-loss{loss:.3f}-val_loss{val_loss:.3f}.h5',
        monitor='val_loss', save_weights_only=True, save_best_only=True, period=3)

    reduce_lr = ReduceLROnPlateau(monitor='val_loss', factor=0.1, patience=3, verbose=1)
    early_stopping = EarlyStopping(monitor='val_loss', min_delta=0, patience=10, verbose=1)


[error]
Traceback (most recent call last):
  File "train.py", line 194, in <module>
    _main()
  File "train.py", line 69, in _main
    callbacks=[logging, checkpoint])
  File "C:\Users\ilove\AppData\Roaming\Python\Python37\lib\site-packages\keras\legacy\interfaces.py", line 91, in wrapper
    return func(*args, **kwargs)
  File "C:\Users\ilove\AppData\Roaming\Python\Python37\lib\site-packages\keras\engine\training.py", line 1418, in fit_generator
    initial_epoch=initial_epoch)
  File "C:\Users\ilove\AppData\Roaming\Python\Python37\lib\site-packages\keras\engine\training_generator.py", line 251, in fit_generator
    callbacks.on_epoch_end(epoch, epoch_logs)
  File "C:\Users\ilove\AppData\Roaming\Python\Python37\lib\site-packages\keras\callbacks.py", line 79, in on_epoch_end
    callback.on_epoch_end(epoch, logs)
  File "C:\Users\ilove\AppData\Roaming\Python\Python37\lib\site-packages\keras\callbacks.py", line 429, in on_epoch_end
    filepath = self.filepath.format(epoch=epoch + 1, **logs)
KeyError: 'val_loss'

谁能找出问题来帮助我？

在此先感谢您的帮助。

Answer 1

此回调在迭代3的末尾运行。

    checkpoint = ModelCheckpoint(log_dir + 'ep{epoch:03d}-loss{loss:.3f}-val_loss{val_loss:.3f}.h5',
        monitor='val_loss', save_weights_only=True, save_best_only=True, period=3)

错误消息声称执行时， logs变量中没有val_loss:

filepath = self.filepath.format(epoch=epoch + 1, **logs)

如果在没有validation_data的情况下调用fit，则会发生这种情况。

我将从简化模型检查点的路径名开始。在名称中包含纪元可能就足够了。