StopIteration: 'PngImageFile' object is not subscriptable

我的环境是ubuntu 16.04, keras 2.1.5,然后在运行vgg代码的时候，出现了如下的错误：

Traceback (most recent call last):
  File "/home/eric/anaconda3/lib/python3.6/site-packages/keras/utils/data_utils.py", line 578, in get
    inputs = self.queue.get(block=True).get()
  File "/home/eric/anaconda3/lib/python3.6/multiprocessing/pool.py", line 644, in get
    raise self._value
  File "/home/eric/anaconda3/lib/python3.6/multiprocessing/pool.py", line 119, in worker
    result = (True, func(*args, **kwds))
  File "/home/eric/anaconda3/lib/python3.6/site-packages/keras/utils/data_utils.py", line 401, in get_index
    return _SHARED_SEQUENCES[uid][i]
  File "/home/eric/anaconda3/lib/python3.6/site-packages/keras/preprocessing/image.py", line 825, in __getitem__
    return self._get_batches_of_transformed_samples(index_array)
  File "/home/eric/anaconda3/lib/python3.6/site-packages/keras/preprocessing/image.py", line 1233, in _get_batches_of_transformed_samples
    img = self.image_data_generator.preprocessing_function(img)
  File "/home/eric/anaconda3/lib/python3.6/site-packages/keras/applications/imagenet_utils.py", line 178, in preprocess_input
    mode=mode)
  File "/home/eric/anaconda3/lib/python3.6/site-packages/keras/applications/imagenet_utils.py", line 132, in _preprocess_symbolic_input
    x = x[..., ::-1]
TypeError: 'PngImageFile' object is not subscriptable

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "vgg16_finetune.py", line 340, in <module>
    callbacks=[tbCallBack,csvlog,checkpointer])
  File "/home/eric/anaconda3/lib/python3.6/site-packages/keras/legacy/interfaces.py", line 91, in wrapper
    return func(*args, **kwargs)
  File "/home/eric/anaconda3/lib/python3.6/site-packages/keras/engine/training.py", line 2192, in fit_generator
    generator_output = next(output_generator)
  File "/home/eric/anaconda3/lib/python3.6/site-packages/keras/utils/data_utils.py", line 584, in get
    six.raise_from(StopIteration(e), e)
  File "<string>", line 3, in raise_from
StopIteration: 'PngImageFile' object is not subscriptabl

解决方法

查资料发现这是keras 2.1.5的bug,我的做法是回滚：

pip install keras==2.1.4

参考文献

[1].新版Keras版本2.1.5不兼容.​​https://zhuanlan.zhihu.com/p/35146669​​