Is it possible to modify an existing TensorFlow computation graph?

Question

TensorFlow graph is usually built gradually from inputs to outputs, and then executed. Looking at the Python code, the inputs lists of operations are immutable which suggest

Answer 1

Yes, tf.Graph are build in an append-only fashion as @mrry puts it.

But there's workaround:

Conceptually you can modify an existing graph by cloning it and perform the modifications needed along the way. As of r1.1, Tensorflow provides a module named tf.contrib.graph_editor which implements the above idea as a set of convinient functions.