基于Keras的误差多分类神经网络

我从我的NN代码中收到了一个相当恼人的错误,希望对Keras的工作方式有更深入了解的人可以向我解释为什么我会遇到这个错误。非常感谢您的帮助! 错误:

AttributeError: 'DirectoryIterator' object has no attribute 'ndim'

错误来自:

    Traceback (most recent call last):
    File "C:\Users\Cameron\Desktop\AI\CubeFieldNN_Train -fix.py", line 80, in <module>
    validation_steps = (validation_samples / batch_size))

代码:

NN.fit(
train_set, train_labels,
batch_size = batch_size,
epochs = epochs,
validation_data = (validation_set, validation_labels),
validation_steps = (validation_samples / batch_size))

完整代码: https://pastebin.com/V1YwJW3X

完全错误:

    Traceback (most recent call last):
  File "C:\Users\Cameron\Desktop\AI\CubeFieldNN_Train -fix.py", line 80, in <module>
    validation_steps = (validation_samples / batch_size))
  File "C:\Python\lib\site-packages\keras\models.py", line 1002, in fit
    validation_steps=validation_steps)
  File "C:\Python\lib\site-packages\keras\engine\training.py", line 1630, in fit
    batch_size=batch_size)
  File "C:\Python\lib\site-packages\keras\engine\training.py", line 1476, in _standardize_user_data
    exception_prefix='input')
  File "C:\Python\lib\site-packages\keras\engine\training.py", line 76, in _standardize_input_data
    data = [np.expand_dims(x, 1) if x is not None and x.ndim == 1 else x for x in data]
  File "C:\Python\lib\site-packages\keras\engine\training.py", line 76, in <listcomp>
    data = [np.expand_dims(x, 1) if x is not None and x.ndim == 1 else x for x in data]
AttributeError: 'DirectoryIterator' object has no attribute 'ndim'