Answer: Python Puzzler #871

The answer is B. The program prints:

[11, 12, 13, 14]

Why?

append adds one item to the end of the list each time round the loop. The loop runs for n = 1, 2, 3, 4.

Trace table

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

n	n + 10	results so far
1	11	[11]
2	12	[11, 12]
3	13	[11, 12, 13]
4	14	[11, 12, 13, 14]

The code again

results = []
for n in range(1, 5):
    results.append(n + 10)
print(results)