Step: Loops: for with range()

range(start, stop) generates integers from start up to (not including) stop — perfect for counting loops.

Why it matters: range() avoids allocating an actual list of numbers just to loop over them.

Example: list(range(1, 4)) is [1, 2, 3].

Your turn: sum the integers 1 through 5 with for i in range(1, 6): total += i.

Pitfall: range(1, 6) stops before 6 — a classic off-by-one if you expect it to include 6.