Set Up Python and Write Fundamental Programs

By the end of this lesson, you'll be able to

  • Get a local Python environment fully working — install, VS Code, virtual environments, and package management with pip
  • Read and write Python control flow (if/elif/else, for, while) and translate what you already know from another language into Python's syntax
  • Handle errors with try/except/finally, order multiple except clauses correctly, and read a traceback to find what actually broke

Why it matters

Every agent you’ll build later — a LangChain chain, a LangGraph state machine — is still just Python underneath. If environment setup, control flow, and error handling aren’t automatic, debugging an agent’s logic later means debugging Python and the framework at once. This lesson makes sure Python itself is never the bottleneck.

Audience note: this section assumes the learner already knows how to code. It covers what’s specific to Python’s tooling and execution model — not general programming concepts.

Callout: none of this is required for the sandbox exercises in this course — those run entirely in your browser. You’ll need this setup only when you get to the downloadable local projects later in the course.