A Python self-check tests operation contracts through twelve questions with explanations.
Review the related lessons
- NumPy slices and indexed copies: verify who owns the buffer
- NumPy broadcasting: declare axes and bound integer arithmetic
- Pandas nullable integers: missing amounts are not zero
- Pandas joins: cardinality validation and missing lookup keys
Common Mistakes
Distinguish input validation, state ownership and deployment guarantees. Results stay in this browser; this self-check supplies no credential or hosted code execution.