After learning Chapter 5 of deep learning with Python, deeply learn the thermodynamic diagram for computer vision
5.4.3 visualization class activation
when running the code in tensorflow 2.0 environment

grads = K.gradients(african_elephant_output, last_conv_layer.output)[0]

replace with

grads = tf.keras.backend.gradients(african_elephant_output, last_conv_layer.output)[0]

The following errors still occur

tf.gradients is not supported when eager execution is enabled. Use tf.GradientTape instead.

Solution

with tf.GradientTape() as gtape:
    grads = gtape.gradient(african_elephant_output, last_conv_layer.output)

Full code reference

reference resources:

https://stackoverflow.com/questions/58322147/how-to-generate-cnn-heatmaps-using-built-in-keras-in-tf2-0-tf-keras