Answer: Python Puzzler #940

The answer is B. The program prints:

[9, 16]

Checked by running the program for real.

append adds one item to the end of the list each time round the loop. The loop runs for n = 3, 4.

A trace table follows the program step by step. Here’s this one:

n	n * n	results so far
3	9	[9]
4	16	[9, 16]

results = []
for n in range(3, 5):
    results.append(n * n)
print(results)

Try it: change one number in the program and predict the new output before you run it.