KeyError: pop('hari') missing

What this problem practises

Dictionaries fail loudly on a missing key with KeyError, quietly through get(), and in genuinely surprising ways when you modify a dict while iterating it or rely on a duplicate key silently replacing the earlier entry.

This is a fix-the-bug problem: a short program is given in its broken state, and the task is to repair the code so it produces the required output. The interactive editor runs your fixed version in the browser and checks it for you — no setup, no local interpreter.

Difficulty: medium — expect to hold two interacting rules in your head at once, such as a boundary combined with a mutation.

The challenge

This program crashes with KeyError because 'hari' is not in the dictionary. Fix it so it prints 59.

The code runs in PyDebug’s in-browser compiler. Open the problem, run the snippet, watch the exact error or output, and keep iterating until it is right. Signed-in solves count toward XP and your daily streak.

The snippet

The interactive editor pre-fills exactly this code, broken and ready to repair:

marks = {'laxmi': 59, 'sita': 50}
print(marks.pop('hari'))

More dictionaries problems

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• Summing dictionary values medium
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Keep going

• Python debugging guide — a systematic method for finding bugs like this one fast.
• Browse every dictionaries problem in this topic.
• Common Python errors and what they actually mean, plus the Python glossary for any term used on this page.