## Table of Contents + [Lab 9 Home](/labs/lab09) + [Part 1: Exercises](/exercises/ex08_files_tracing_and_sorting) + [Part 2: Secret Message](/labs/lab09/secret-message) + [Knowledge Check](/labs/lab09/check) {{-- + [Part 0: Warm-Up](/labs/lab09/warmup) + [Part 1: Tests & List Comprehensions](/labs/lab09/testing-and-comprehensions) + [Part 2: File Exercises](/labs/lab09/files) + [Extra: Additional Exercises](/labs/lab09/extra) --}}