$ python practice.py --mode=debug

Find the bug. Fix the code. Actually learn Python.

PyDebug throws you real broken Python code and tricky output-prediction puzzles — solved right in your browser, no separate compiler tab needed.

🐛 Start Free Challenge
Already have an account? Log in
def total(items):
    total = 0
    for i in range(1, len(items)):
        total += items[i]
    return total
# IndexError risk — off-by-one bug. Can you spot it?
🐞

Fix the Bug

Broken code, real errors. Edit it in the playground until it runs clean.

🧠

Predict the Output

Read tricky Python snippets and guess exactly what they print — no running allowed.

Built-in Playground

Python runs directly in your browser. No installs, no other compiler websites.

Free + Premium

Solid free library to start, deeper premium problem sets when you're ready to go further.

Ten minutes a day beats a weekend cram

One bug, one prediction, one small win — that's all it takes to build a real Python habit. PyDebug tracks your streak and XP so you can see your consistency add up day by day, and picks up right where you left off.

🔥 Daily streak tracking
📈 XP for every problem solved
🏆 Leaderboard to stay motivated

⭐ Go further with Premium

Unlock the full problem library, unlimited hints with no ads, and an ad-free playground.

Start free, upgrade anytime