An Introduction to Reinforcement Learning with OpenAI Gym, RLlib, and Google Colab

One possible definition of reinforcement learning (RL) is a computational approach to learning how to maximize the total sum of rewards when interacting with an environment. While a definition is useful, this tutorial aims to illustrate what reinforcement learning is through images, code, and video examples and along the way introduce reinforcement learning terms like agents and environments. As a previous post noted, machine learning (ML), a sub-field of AI, uses neural networks or other types of mathematical models to learn how to interpret complex patterns. Two areas of ML that have recently become very popular due to their high level of maturity are supervised learning (SL), in which neural networks learn to make predictions based on large amounts of data, and reinforcement learning (RL), where the networks learn to make good action decisions in a trial-and-error fashion, using a simulator. RL is the tech behind mind-boggling successes such as DeepMind's AlphaGo Zero and the StarCraft II AI (AlphaStar) or OpenAI's DOTA 2 AI ("OpenAI Five").