The major changes that you will experience while migrating from TF 1.x to TF 2.0 concern API cleanup.
Many of the APIs in TF 2.0 have either been removed or moved. Major changes include the removal of tf.app, tf.flags, and tf.logging in favor of other Python modules, such as absl-py and the built-in logging system.
One of the largest changes that has been made in TF 2.0 code-wise is eager execution. TF 1.x requires users to manually stitch an abstract syntax tree using tf.* calls to build a computational graph, which it will run with session.run(). This means that TF 2.0 code runs line by line, and so tf.control_dependancies() is no longer needed.
The session.run() call in TF 1.x is very similar to a simple function. The user specifies the inputs and the function to be called, and it returns a set of outputs. This code flow is completely...