Files and errors

Read real data safely and handle failures without crashing.

Beginner 14 min read Lesson 8 of 480 Challenge included

What you will be able to do

Open files with a context manager
Catch specific exceptions
Write a small automation script

Real programs deal with files and failure. A context manager closes the file even when an error occurs. Catch only the exceptions you can handle.

files.pyPython

from pathlib import Path

path = Path("scores.csv")

try:
    with path.open(encoding="utf-8") as file:
        rows = [line.strip().split(",") for line in file if line.strip()]
except FileNotFoundError:
    print("No scores file found — starting empty.")
    rows = []

print(f"Loaded {len(rows)} rows")

Your turn

Count the lines

Medium

Read notes.txt and print how many non-empty lines it contains. Handle the missing-file case.

PYTHON · starter

from pathlib import Path

# your code here

Check your understanding before moving on.

Knowledge checkQuestion 1

Why use a with statement to open a file?

Select an answer to continue

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Next: Strings and formatting

Lesson 8 of 480 · 0% of course