title: model.get_weights() vs model.trainable_variables Tensorflow
body: <p><code>model.get_weights()</code> and <code>model.trainable_variables</code> in Tensorflow seems to be returning same values in different data types. Former returns list of arrays and latter array of tensors. (If I am not mistaken)</p>
  <p>Please, explain in which context is better to use each?
  Also, I was trying to compare them but had no luck, if possible please help with a comparison code.</p>
  <p>Thank you.</p>