Implementing the train_step Method in Keras 3: From Errors to Solutions

Official code example hasn’t kept up with framework updates

Implementing the train_step Method in Keras 3: From Errors to Solutions. Image by DALL-E-3

Keras has been updated to version 3.0, but many code examples on the official website have not been maintained in time. So, when you use Pytorch as the backend framework, these code examples will likely fail.

For instance, take the example related to the VAE model, and another concerning the GAN model.

Both examples share a common feature: they rewrite the train_step method of keras.Model to implement a custom model training and gradient update process. However, following these examples will likely result in errors.

After several failed attempts, I finally figured out how to write the train_step method correctly. Today, I will share my solution with you, hoping to help you solve similar problems.

If you are unfamiliar with the new changes in Keras 3, you can read my deep dive article here:

Keras 3.0 Tutorial: End-to-End Deep Learning Project Guide

Introducing Some Background Knowledge