How does iterable unpacking work?

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**Unpacking** assigns the elements of an iterable to multiple targets at once: `a, b, c = [1, 2, 3]`. The count must match — unless you use a **starred target** `*rest`, which greedily absorbs the remaining items into a **list**: `first, *middle, last = [1, 2, 3, 4, 5]` gives `first=1`, `middle=[2,3,4]`, `last=5`. Exactly one star is allowed, and it works at either end or the middle.

Unpacking powers several idioms:

- **Swapping** without a temp: `a, b = b, a` (the right side becomes a tuple first).
- **Nested** unpacking: `(name, (lat, lng)) = record`.
- **In function calls**: `f(*args, **kwargs)` and merging: `merged = {**d1, **d2}`, `combined = [*a, *b]`.
- **`for` loops over pairs**: `for k, v in d.items():`.
- **Throwaway** with `_`: `_, value = pair`.

**Interview tip:** show the **starred** unpack (`first, *rest = ...` → `rest` is a *list*) and the tuple-swap, and mention `{**a, **b}` / `[*a, *b]` for merging. Knowing the star captures into a list (not a tuple) is a nice preci

How does iterable unpacking work?

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