AttributeError: 'Tensor' object has no attribute 'numpy'

I suspect the place where you copied the code from had eager execution enabled, i.e. had invoked tf.enable_eager_execution() at the start of the program.

You could do the same.Hope that helps.

UPDATE: Note that eager execution is enabled by default in TensorFlow 2.0. So the answer above applies only to TensorFlow 1.x

Since the accepted answer did not solve the problem for me so I thought it might be helpful for some people who face the problem and that already have tensorflow version >= 2.2.0 and eager execution enabled.

The issue seems to be that for certain functions during the fitting model.fit()the @tf.function decorator prohibits the execution of functions like tensor.numpy() for performance reasons.

The solution for me was to pass the flag run_eagerly=True to the model.compile() like this:

model.compile(..., run_eagerly=True)

This can also happen in TF2.0 if your code is wrapped in a @tf.function or inside a Keras layer. Both of those run in graph mode. There's a lot of secretly broken code out of there because behavior differs between eager and graph modes and people are not aware that they're switching contexts, so be careful!