A Python self-check tests operation contracts through twelve questions with explanations.
Review the related lessons
- Python lists: slicing copies the outer sequence, not nested objects
- Python dictionaries: insertion order and duplicate-key replacement
- Python tuples: immutable containers can still contain mutable state
- Python dataclasses: frozen fields require an immutable value model
Common Mistakes
State the input and ownership rule before choosing an output. This browser self-check is not a credential or a hosted code judge.