best-practices
List vs Tuple vs Set
When to use each collection type for compilation performance.
Published May 30, 2026
List
Best for: iteration, appending, indexed access. Mutable.
Tuple
Best for: fixed records, return values, dictionary keys. Immutable and slightly faster for read-only.
Set
Best for: membership testing, deduplication. Partial support — some operations may fall back.
When to Choose
| Operation | Best Type |
|---|---|
| Loop over sequence | list or tuple |
| Append items | list |
| Lookup by index | list or tuple |
| Check membership | set (if supported) or dict |
| Return multiple values | tuple |