Question about 'NoneType' object is not subscriptable

[fangchao]

Congrats on the awesome work done and thanks for sharing.

I have create a model via subclassing and wanna to convert saved model to frozen graph.

But I have got a NoeType error at line x=tf.TensorSpec(model.inputs[0].shape, model.inputs[0].dtype))

model = tf.keras.models.load_model(saved_model, custom_objects={'loss_fn': loss_fn})
model.summary()

# Convert Keras model to ConcreteFunction
full_model = tf.function(lambda x: model(x))
full_model = full_model.get_concrete_function(
         x=tf.TensorSpec(model.inputs[0].shape, model.inputs[0].dtype))

Do you know how to solve this problem?

Thanks a lot and wait for you reply.