Q values loss per episode and mean absolute error

I am new to deep reinforcement learning! I am following this code for my adaptation problem (doing actions)

https://github.com/jaromiru/AI-blog/blob/master/CartPole-DQN.py

I am wondering how I can evaluate the training, I already got the average rewards, but how can I get the average Q values, loss per episode, and average absolute error. to evaluate my agent please!

I will be grateful if you can help me!