Tuples & Sets

Tuples and sets complete the container toolbox.

Tuple — a list that never changes

point = (3, 4)
point[0]          # 3
point[0] = 9      # TypeError!

Use tuples for fixed groups: coordinates, RGB colors, (day, month, year). They signal intent: "this shape does not change". One element needs a comma: (42,).

Set — uniqueness, fast membership

tags = {"python", "coding", "python"}
len(tags)          # 2 — duplicates vanish
"python" in tags   # very fast, even for huge sets
tags.add("learning")

Sets have no order and no duplicates — perfect for "have I seen this?" checks and deduplication: set(my_list) removes duplicates.

Choosing the container

| Need | Use | | --- | --- | | Ordered items, will change | list | | Fixed shape, never changes | tuple | | Uniqueness + fast lookup | set | | Key → value lookups | dict (next lesson) |