尝试在Keras中加载序列模型时出现“KeyError:0”

Question

我用Google Colab在Keras中训练了一个序列模型来处理Google涂鸦数据集。我在这里做一些简单的图像分类。

以下功能定义了我的模型的体系结构：

def create_model(input_shape):
   model = keras.Sequential()  
   model.add(layers.Conv2D(16, (3, 3), padding = 'same', input_shape = input_shape, activation = 'relu'))
   model.add(layers.BatchNormalization(axis = 3)) 
   model.add(layers.MaxPooling2D(pool_size = (2, 2)))

   model.add(layers.Conv2D(32, (3, 3), padding = 'same', activation = 'relu'))
   model.add(layers.BatchNormalization(axis = 3))
   model.add(layers.MaxPooling2D(pool_size = (2, 2)))

   model.add(layers.Conv2D(64, (3, 3), padding = 'same', activation = 'relu'))
   model.add(layers.BatchNormalization(axis = 3))
   model.add(layers.MaxPooling2D(pool_size = (2,2)))

   model.add(layers.Flatten())
   model.add(layers.Dense(128, activation = 'relu'))
   model.add(layers.Dense(28, activation = 'softmax')) 

   return model

下面的代码创建、编译并适合它：

doodle_model = create_model((image_size, image_size, 1)) #image_size = 28
doodle_model.compile (optimizer = "Adam", loss = "categorical_crossentropy", metrics = ["accuracy"])
doodle_model.fit (x = X_train, y = Y_train, epochs = 4, batch_size = 256)

我用这个模型得到了很好的结果，所以我决定保存它，以便以后在web应用程序中部署它。我用过：

doodle_model.save("my_model.h5")

保存模型

但是，当我再次尝试使用：

from keras.models import load_model
model = load_model ("my_model.h5")

为了确保它被正确保存，我得到以下错误。。。

KeyError                                  Traceback (most recent call last)
<ipython-input-61-6cde554a8add> in <module>()
      1 from keras.models import load_model
      2 
----> 3 model = load_model ("my_model.h5")

/usr/local/lib/python3.6/dist-packages/keras/models.py in load_model(filepath, custom_objects, compile)
    268             raise ValueError('No model found in config file.')
    269         model_config = json.loads(model_config.decode('utf-8'))
--> 270         model = model_from_config(model_config, custom_objects=custom_objects)
    271 
    272         # set weights

/usr/local/lib/python3.6/dist-packages/keras/models.py in model_from_config(config, custom_objects)
    345                         'Maybe you meant to use '
    346                         '`Sequential.from_config(config)`?')
--> 347     return layer_module.deserialize(config, custom_objects=custom_objects)
    348 
    349 

/usr/local/lib/python3.6/dist-packages/keras/layers/__init__.py in deserialize(config, custom_objects)
     53                                     module_objects=globs,
     54                                     custom_objects=custom_objects,
---> 55                                     printable_module_name='layer')

/usr/local/lib/python3.6/dist-packages/keras/utils/generic_utils.py in deserialize_keras_object(identifier, module_objects, custom_objects, printable_module_name)
    142                 return cls.from_config(config['config'],
    143                                        custom_objects=dict(list(_GLOBAL_CUSTOM_OBJECTS.items()) +
--> 144                                                            list(custom_objects.items())))
    145             with CustomObjectScope(custom_objects):
    146                 return cls.from_config(config['config'])

/usr/local/lib/python3.6/dist-packages/keras/models.py in from_config(cls, config, custom_objects)
   1404     @classmethod
   1405     def from_config(cls, config, custom_objects=None):
-> 1406         if 'class_name' not in config[0] or config[0]['class_name'] == 'Merge':
   1407             return cls.legacy_from_config(config)
   1408 

KeyError: 0

据我所知，KeyErrors与python字典有关，但我不确定为什么在这里遇到KeyError。如果您能帮助我理解为什么会出现这个错误，以及如何解决这个错误，我们将不胜感激。

每一段代码，行后

----> 3 model = load_model ("my_model.h5")

这个错误信息的内部代码是Keras的，不是我写的。