Mixed numbers
Input
filter_evens([1, 2, 3, 4, 5, 6])
Output
[2, 4, 6]
Only even numbers 2, 4, 6 are kept, in the original order.
Full lesson preview
Filter Even Numbers
Return a new list containing only the even numbers from the input list, preserving order.
Python practice8 minLoops & IterationBeginnerLast updated March 15, 2026
Problem statement
Write a function filter_evens(nums) that takes a list of integers nums and returns a new list containing only the even integers from nums in the same order they appeared. If there are no even numbers, return an empty list.
Task
Practice iterating over a list, applying a condition, and building a new list.
Examples
Input format
A single list of integers, e.g. [0, 1, 2].
Output format
A list of integers containing only even values, e.g. [0, 2].
Constraints
Do not use external libraries. Aim for O(n) time and O(n) output space (new list).
Samples
Sample 1
Input
filter_evens([0, -2, 7])
Output
[0, -2]
0 and -2 are even; 7 is odd and removed.