Does not run when using the official sample code for Keras3

Issue Type

Documentation Bug

Source

binary

Keras Version

Keras 3.4.1

Custom Code

OS Platform and Distribution

Windows

Python version

3.12.4

GPU model and memory

Nvidia A3000

Current Behavior?

I got an error when using the official Keras3 instance code. When I took the last step of training I got the following error: AttributeError: 'list' object has no attribute 'shape'

Standalone code to reproduce the issue or tutorial link

Using the original code, no changes.
https://github.com/keras-team/keras-io/blob/master/guides/custom_train_step_in_torch.py

Relevant log output

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[5], line 22
     15 gan = GAN(discriminator=discriminator, generator=generator, latent_dim=latent_dim)
     16 gan.compile(
     17     d_optimizer=keras.optimizers.Adam(learning_rate=0.0003),
     18     g_optimizer=keras.optimizers.Adam(learning_rate=0.0003),
     19     loss_fn=keras.losses.BinaryCrossentropy(from_logits=True),
     20 )
---> 22 gan.fit(dataloader, epochs=1)

File c:\Users\C\miniconda3\envs\learn100\Lib\site-packages\keras\src\utils\traceback_utils.py:122, in filter_traceback.<locals>.error_handler(*args, **kwargs)
    119     filtered_tb = _process_traceback_frames(e.__traceback__)
    120     # To get the full stack trace, call:
    121     # `keras.config.disable_traceback_filtering()`
--> 122     raise e.with_traceback(filtered_tb) from None
    123 finally:
    124     del filtered_tb

Cell In[4], line 27
     25     real_images = real_images[0]
     26 # Sample random points in the latent space
---> 27 batch_size = real_images.shape[0]
     28 random_latent_vectors = keras.random.normal(
     29     shape=(batch_size, self.latent_dim), seed=self.seed_generator
     30 )
     32 # Decode them to fake images

AttributeError: 'list' object has no attribute 'shape'

keras-team / keras-io

Does not run when using the official sample code for Keras3 #1898