Unit 5: Loops & Automation

Repetition becomes automation only when you understand what changes on each pass and why the repetition stops.

A loop that produces the right output once can still be wrong if it skips a case, repeats one twice, mutates the wrong state, or never terminates.

Watch one iteration at a time

You will work with for, range(), while, counters, accumulators, break, and the state that controls termination.

Instead of staring at a loop as one block of code, trace it as a sequence:

iteration -> current value -> condition -> body effect -> next state

That trace makes off-by-one errors visible. It also explains why range(5) does not mean “the numbers one through five,” and why a while loop needs a state change that can eventually make its condition false.

Automation test

Your Unit evidence is one useful loop plus a loop-forensics record. Include the starting state, at least three iterations, the termination condition, final state, and one controlled failure such as a missing update or wrong range endpoint.

The goal is not “use a loop.” The goal is to prove that the loop processes the intended cases and has a reason to stop.