Time: 0:00
Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).
This bug belongs to the logic errors pattern
The wrong operator, an inverted condition, a formula the right way round but backwards.
What went wrong: Unlike JavaScript's indexOf(), Python's list.index() raises a ValueError when the element is not found.
The fix: Check membership with in before calling index(): items.index(target) if target in items else -1
Remember: In Python, list.index() raises ValueError when an item is missing; guard with in target.
The pattern behind it: logic errors.
Paste this into any web page or blog post. Visitors fix the bug right there, in their browser.
<iframe src="https://trybughunt.com/embed/56636682-89ae-4ea7-8b90-d9f85e3145d3" title="Debugging challenge: Index method on list raises ValueError when item is missing" width="100%" height="580" loading="lazy" style="border:1px solid #d4d4d8;border-radius:12px;max-width:760px"></iframe>
<p style="font-size:14px">Debugging challenge from <a href="https://trybughunt.com/challenges/56636682-89ae-4ea7-8b90-d9f85e3145d3">TryBugHunt</a></p>