How to add regularizations in TensorFlow?

Question

I found in many available neural network code implemented using TensorFlow that regularization terms are often implemented by manually adding an additional term to loss valu

Answer 1

I tested tf.get_collection(tf.GraphKeys.REGULARIZATION_LOSSES) and tf.losses.get_regularization_loss() with one l2_regularizer in the graph, and found that they return the same value. By observing the value's quantity, I guess reg_constant has already make sense on the value by setting the parameter of tf.contrib.layers.l2_regularizer.