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TypeError: sorting mixed text + numbers
🐛 Fix the bug Topic: sorting Difficulty: easy Free
What this problem practises
The two sorting APIs are not interchangeable: sorted() returns a brand-new list while list.sort() sorts in place and returns None. Key functions compare the values they extract, and comparing mixed types raises TypeError.
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: easy — the fix or the trick is normally a single line, and a careful read should be enough.
The challenge
This program crashes with TypeError because text and numbers cannot be compared. Remove the words so it prints [3, 31].
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:
nums = [3, 'grape', 31, 'cat']
nums.sort()
print(nums)More sorting problems
Keep going
- Python debugging guide — a systematic method for finding bugs like this one fast.
- Browse every sorting problem in this topic.
- Common Python errors and what they actually mean, plus the Python glossary for any term used on this page.