The answer is B. The program prints:
[6, 9, 12]
Why?
append adds one item to the end of the list each time round the loop. The loop runs for n = 2, 3, 4.
Trace table
A trace table follows the program step by step. Here’s this one:
| n | n * 3 | results so far |
|---|---|---|
| 2 | 6 | [6] |
| 3 | 9 | [6, 9] |
| 4 | 12 | [6, 9, 12] |
The code again
results = []
for n in range(2, 5):
results.append(n * 3)
print(results)Try it: change one number in the program and predict the new output before you run it.