Writing code is only half the job. Reading errors, finding bugs, and keeping the codebase tidy take just as much time. This section gives you the tools to do all three.

What’s in this section

1. Reading tracebacks — what Python tells you when things go wrong
2. Using the debugger — pause your program and inspect it live
3. Basic logging — replace print with something you can turn off
4. Formatting and linting with Ruff — one tool for clean code
5. PEP 8 basics — the style conventions every Python codebase follows

These skills compound. The earlier you build them, the less time you’ll spend stuck.