Reinforcement learning programming implementations • /r/MachineLearning

It's a cool opener on the concepts, but leaves the actual implementations very hazy. For instance, I would love to understand how to create my own environment (or task, for that matter). Instead, this tutorial just throws ready-made stuff at you which, I reckon, isn't very helpful in actually understanding. If there exists good explanations involving programming I would be very keen in looking into them.