Answer: Python Puzzler #515

The answer is A. The program prints:

banana
What the program prints
Checked by running the program for real.

Why?

A negative position counts from the end: -1 is the last item, -2 the one before it. So -3 means item number 3 from the end.

Trace table

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

positionnegative positionitem
0-6apple
1-5mango
2-4grape
3-3banana
4-2carrot
5-1plum

The code again

basket = ["apple", "mango", "grape", "banana", "carrot", "plum"]
print(basket[-3])

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