How it works...

In this recipe, we print out the state array for every step. But what does each float in the array mean? We can find more information about CartPole on Gym's GitHub wiki page: https://github.com/openai/gym/wiki/CartPole-v0. It turns out that those four floats represent the following:  

• Cart position: This ranges from -2.4 to 2.4, and any position beyond this range will trigger episode termination.
• Cart velocity.
• Pole angle: Any value less than -0.209 (-12 degrees) or greater than 0.209 (12 degrees) will trigger episode termination.
• Pole velocity at the tip.

In terms of the action, it is either 0 or 1, which corresponds to pushing the cart to the left and to the right, respectively.

The reward in this environment is +1 for every timestep before the episode terminates. We can also verify this by printing out the reward for every step. And the total reward is simply the number of timesteps.