Python Coding challenge - Day 776| What is the output of the following Python Code?

 

Code Explanation:

1. Importing the itertools Library

import itertools

This imports the itertools module — a powerful built-in Python library for iterator-based operations.

It provides tools for efficient looping, combining, grouping, and generating iterable data.

2. Creating the First List

nums1 = [1, 2, 3]

Defines a list named nums1 containing three integers — [1, 2, 3].

3. Creating the Second List

nums2 = [4, 5, 6]

Defines another list named nums2 containing [4, 5, 6].

4. Merging Both Lists Using itertools.chain()

merged = itertools.chain(nums1, nums2)

The function itertools.chain() combines multiple iterables into a single sequence without creating a new list in memory.

Here it links both lists into one continuous iterable equivalent to:

[1, 2, 3, 4, 5, 6]

Importantly, merged is an iterator, not a list — it generates elements one by one as needed.

5. Filtering Even Numbers Using filter()

evens = list(filter(lambda x: x % 2 == 0, merged))

The filter() function applies a lambda function to each item in merged.

The lambda function lambda x: x % 2 == 0 returns True for even numbers.

So only even numbers are kept.

The result of filter() is converted to a list, giving:

evens = [2, 4, 6]

6. Printing the Sum and Last Even Number

print(sum(evens), evens[-1])

sum(evens) adds all elements in [2, 4, 6] → 2 + 4 + 6 = 12.

evens[-1] gives the last element of the list → 6.

Therefore, the output will be:

12 6

Final Output:

12 6

500 Days Python Coding Challenges with Explanation