What is the meaning of the “None” in model.summary of KERAS?

Question

What is the meaning of the (None, 100) in Output Shape? Is this(\"None\") the Sample number or the hidden dimension?

Answer 1

Yes, None in summary means a dynamic dimension of a batch (mini batch). This is why you can set any batch size to your model.

The summary() method is part of TF that incorporates Keras method print_summary().