Pull request for code updation

[manavrmoorthy]

The summary of changes included are as follows:

chapter 2:

• tensorflow 2.0.0 does not run on python 3.10 (version used by colab currently)
• tensorflow gpu removed: https://github.com/tensorflow/tensorflow/releases/tag/v2.12.0
• upgrading tf-explain to 0.3.1 - and explainer.explain arguments ordering has changed, so made that generic

https://github.com/PracticalDL/Practical-Deep-Learning-Book/issues/173 - don't know the seriousness of this issue, skipping it for now. i am getting comparable times for training both models when i tried it, and there is nothing that specifically is needed to be changed in the code here for this

chapter 3:

• adding kaggle CLI support to make data download easier - to download any data from kaggle and start training models
• fit_generator -> fit function, and predict_generator -> predict function since they now support generator objects and the former functions are going to get deprecated soon
• the gcloud sessions are not using the same runtime (so we need to re-download data) - using the same strategies to download through kaggle CLI in both notebooks 1 and 2
• deleted deprecated files
• formatted the code

chapter 4:

• removing deprecated files
• the gcloud sessions are not using the same runtime (so we need to re-download data) so writing outputs to gdrive to make sure things are running and outputs are accessible for subsequent notebooks in colab
• renaming 4/1 notebook - since it had underscores instead of hyphens, the colab link in the notebook was not working
• xception added to imports for notebook 1, since it is part of the model_maker
• https://github.com/PracticalDL/Practical-Deep-Learning-Book/issues/163 - fixed
• https://github.com/PracticalDL/Practical-Deep-Learning-Book/issues/164 - fixed
• https://github.com/PracticalDL/Practical-Deep-Learning-Book/issues/169 - fixed
• metric='angular' added for annoy as default arg will be removed in subsequent releases
• removing a duplicate PCA + Annoy section
• https://github.com/PracticalDL/Practical-Deep-Learning-Book/issues/170 - fixed
• time is a negligible factor here, and we do not need it in the plots (since we are using optimised accuracy calculation using numpy from issue 170) - hence, modifying the plots
• removing matplotlib.style.use('seaborn') since it is deprecated
• the final fine-tuning notebook uses Caltech256 features (as per the book), which do not exist, since fine-tuning was done on Caltech101 - hence, renaming those files to caltech101. Can we retain caltech101 to test?
• https://github.com/PracticalDL/Practical-Deep-Learning-Book/issues/167 - fixed, if the above is okay
• formatted the code

chapter 5:

• write_grads and batch_size params have been removed from callback, or will be removed in subsequent releases
• https://github.com/PracticalDL/Practical-Deep-Learning-Book/issues/174 - not able to replicate this issue
• added a pointer to the notebook that suggests that for tensorboard to work without a 403 Forbidden error on Colab, cookies need to be allowed (I faced this issue)
• notebook 3 in chapter 5 is the exact same as notebook 2 in chapter 2 - replaced the file directly
• the autokeras notebook in Colab is named autokeras-error.ipynb - where can we change this to autokeras.ipynb?
• fixing accuracy score calculation in the autokeras notebook
• formatted the code

chapter 6:

• including the download_sample_image function
• formatted the code

chapter 7: no code to update

NOTE - will edit this, as I add more changes.