1.6 Tuple, Set, Dictionary, and Type Conversion

1.6 Tuple, Set, Dictionary, and Type Conversion

After this unit you will: choose the right collection type for each problem.

Key points

Type	Ordered	Mutable	Duplicates
List []	Yes	Yes	Allowed
Tuple ()	Yes	No	Allowed
Set {}	No	Yes	Not allowed
Dict {k: v}	Yes	Yes	Keys are unique

• A one-element tuple needs a comma: (50,).
• A dictionary can be nested: students["s1"]["name"].
• int(3.99) is 3 — int() truncates the decimal part rather than rounding.