Question

What is the output?

nums = [3, 7, 2, 1]
print(len(nums))
print(nums[-1])
print(nums[len(nums)])

Answer 1

The output of the given Python commands are '4' for the length of the list, '1' for the last element in the list, and an IndexError for attempting to access an element beyond the valid range of indices in the list.

Step-by-step explanation:

The student's question involves understanding the output of several Python commands applied to a list nums containing four integers. The first command is len(nums), which returns the length of the list, the second is accessing the last element with nums[-1], and the third is trying to access an element using nums[len(nums)], which will result in an IndexError because list indices are zero-based.

Output Explanation

1. len(nums) will output '4' as there are four elements in the list.
2. nums[-1] will output '1' which is the last element of the list.
3. The expression nums[len(nums)] will cause an error since the highest index in the list is '3' and len(nums) returns
4. . Python lists are zero-indexed, which means the index of the first element is '0'.