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Recursion and a Base Case Demo

Sometimes a function can solve a small piece, then call itself for the rest. The base case stops it. step_down(0) returns immediately; for a positive number, each call uses a smaller number. Without a reachable base case, Python eventually raises RecursionError. For an ordinary list, a loop is usually simpler; here recursion is an optional pattern to recognize and practice on small values.

The complete starter returns a list of numbers ending at zero. Edit main.py: change the sample call from step_down(2) to step_down(3). Run to see [3, 2, 1, 0], then Submit. In the next lesson, you'll build a different recursive function.

Your Task

  1. Change the sample call to step_down(3) without changing the function's base case.
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