happyModel 'tuple' object has no attribute 'lower'

Course Q&A Deep Learning Specialization Convolutional Neural Networks
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I have thoroughly read all the documentation on tf.keras.layers, The Sequential Model and the individual layers. I have also read curious.ai’s posting. None of them seem to address the issue I have.

happy_model_AttributeError
happy_model_AttributeError1240×728 111 KB

It seems to be throwing the AttributeError because of something in the ZeroPadding2D line. I have the commas and the brackets exactly like in the documentation.

Please advise

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We can see from the trace that the exception is thrown while examining the attribute data_format. According to the doc, that parameter is supposed to be a string with value either channels_last or channels_first. Instead, you have a Python tuple and tuples don’t implement a function lower, hence the error. NOTE: if data_format is a string, the very next line checks the value, and throws an exception if it isn’t either channels_first or channels_last.

FWIW, that tuple looks suspiciously like an input_shape :thinking:. In the above Conv2D doc look for the part that says When using this layer as the first layer in a model, provide the keyword argument input_shape (tuple of integers…

Or take a quick peek at the Sequential model doc here

and look for the part that starts… A simple alternative is to just pass an input_shape argument to your first layer:

I have now added content covering this to my Tips for troubles with Sequential and Functional API syntax thread

1 Like
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Thank you very much for this and I have read many of your posts with great interest. I agree with the input_shape suggestion - its a shame the notebook instructions say “Note that for simplicity and grading purposes, you’ll hard-code all the values such as the stride and kernel (filter) sizes.”. I misinterpreted that.

I also note that in the data_format section of args in the tf.keras.layers.ZeroPadding2D documentation, it concludes with " It defaults to the image_data_format value found in your Keras config file at ~/.keras/keras.json . If you never set it, then it will be “channels_last”.

I am sure that with your advice I will sort this out.

Thanks again.

1 Like
4

That is the TF/Keras default, and is consistent with the practice used throughout the deeplearning classes, (m=#inputs, h=input height, w=input width, c=# channels). So most of the time you won’t need to set it in these classes, though there is no downside to being in the habit of explicitly stating it. Cheers