# Second assignment of first week, DLS course 4 **URL:** \ **Category:** Convolutional Neural Networks\ **Tags:** coursera-platform\ **Created:** [October 10, 2023, 6:49pm UTC](https://community.deeplearning.ai/t/second-assignment-of-first-week-dls-course-4/467116 "2023-10-10T18:49:29Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Arman\_Hosse](https://avatars.discourse-cdn.com/v4/letter/a/d9b06d/32.png) [@Arman\_Hosse](https://community.deeplearning.ai/u/Arman_Hosse)\ **Post date:** [October 10, 2023, 6:49pm UTC](https://community.deeplearning.ai/t/second-assignment-of-first-week-dls-course-4/467116/1 "2023-10-10T18:49:29Z")
help! I checked my code millions of time, for the first exercise “happyModel” , I keep receiving an error in second cell after creating def happyModel(), which is : AttributeError Traceback (most recent call last) in 1 happy\_model = happyModel() 2 # Print a summary for each layer ----\> 3 for layer in summary(happy\_model): 4 print(layer) 5 ~/work/release/W1A2/test\_utils.py in summary(model) 34 result = 35 for layer in model.layers: —\> 36 descriptors = [layer. **class**. **name** , layer.output\_shape, layer.count\_params()] 37 if (type(layer) == Conv2D): 38 descriptors.append(layer.padding) /opt/conda/lib/python3.7/site-packages/tensorflow/python/keras/engine/base\_layer.py in output\_shape(self) 2177 “”" 2178 if not self.\_inbound\_nodes: → 2179 raise AttributeError('The layer has never been called ’ 2180 ‘and thus has no defined output shape.’) 2181 all\_output\_shapes = set( AttributeError: The layer has never been called and thus has no defined output shape. I think this error has nothing to do with my code and I don’t know how to fix this problem ---
**Author:** ![TMosh](https://sea1.discourse-cdn.com/dlai/user_avatar/community.deeplearning.ai/tmosh/32/9321_2.png) [@TMosh](https://community.deeplearning.ai/u/TMosh)\ **Post date:** [October 10, 2023, 7:10pm UTC](https://community.deeplearning.ai/t/second-assignment-of-first-week-dls-course-4/467116/2 "2023-10-10T19:10:53Z")
Did you include the input\_shape=(…) parameter in the ZeroPadding2D() layer? ---
**Author:** ![paulinpaloalto](https://sea1.discourse-cdn.com/dlai/user_avatar/community.deeplearning.ai/paulinpaloalto/32/187_2.png) [@paulinpaloalto](https://community.deeplearning.ai/u/paulinpaloalto)\ **Post date:** [October 10, 2023, 8:33pm UTC](https://community.deeplearning.ai/t/second-assignment-of-first-week-dls-course-4/467116/3 "2023-10-10T20:33:05Z")
> [@Arman\_Hosse](#): > > I think this error has nothing to do with my code and I don’t know how to fix this problem Sorry, but I think that error has everything to do with your code. The best idea would be to spend 15 minutes studying [this thread](https://community.deeplearning.ai/t/tips-for-troubles-with-sequential-and-functional-api-syntax/52202) which gives a much nicer explanation of how the Keras Sequential and Functional APIs work than what is given to us in the notebook. Then go back and re-examine your code with that knowledge in mind and I hope that things will be a lot clearer. ---
**Author:** ![paulinpaloalto](https://sea1.discourse-cdn.com/dlai/user_avatar/community.deeplearning.ai/paulinpaloalto/32/187_2.png) [@paulinpaloalto](https://community.deeplearning.ai/u/paulinpaloalto)\ **Post date:** [October 10, 2023, 8:39pm UTC](https://community.deeplearning.ai/t/second-assignment-of-first-week-dls-course-4/467116/4 "2023-10-10T20:39:05Z")
Of course if you still have problems even after studying that thread, please ask more followup questions and we will be here to help. ---
**Author:** ![Arman\_Hosse](https://avatars.discourse-cdn.com/v4/letter/a/d9b06d/32.png) [@Arman\_Hosse](https://community.deeplearning.ai/u/Arman_Hosse)\ **Post date:** [October 11, 2023, 9:49pm UTC](https://community.deeplearning.ai/t/second-assignment-of-first-week-dls-course-4/467116/5 "2023-10-11T21:49:13Z")
thank you!