2 docs tagged with "environment"

LangChain reads provider credentials from environment variables by default. The standard pattern is a .env file loaded with python-dotenv, never a key typed directly into source.

Every model so far in this curriculum has learned from labelled examples — here is the input, here is the correct output. Reinforcement learning removes the labels entirely: an agent takes actions, receives only a scalar signal for how well it did, and has to figure out which of its own past decisions deserve the credit.