basic-programming-learning-phase-1

Module 05 — Files and errors

Concepts

• Opening files: with open(...) as f
• Reading: read(), readlines(), iteration
• Writing: write(), writelines()
• Modes: r, w, a
• Exceptions: try / except / else / finally
• Raising exceptions
• Common errors: FileNotFoundError, ValueError, ZeroDivisionError

Practice prompts

1. Write 3 lines to output.txt, then read and print them.
2. Append a 4th line to the same file.
3. Wrap a division in try/except that handles ZeroDivisionError.
4. Write parse_int(s) that raises ValueError if s isn’t an integer; handle it in a caller.
5. Use finally to print "done" regardless of outcome.

Complete the TODOs in starters.py.