filter() function in Python - Mini Project: Build & Apply

Using the filter() function to select even numbers

📖 Scenario: Imagine you have a list of numbers representing ages of people in a group. You want to find only the even ages to organize a special event for them.

🎯 Goal: You will build a small program that uses the filter() function to select even numbers from a list of ages.

📋 What You'll Learn

Create a list called ages with the exact values: 12, 17, 20, 25, 30, 33, 40

Create a function called is_even that returns True if a number is even

Use the filter() function with is_even and ages to get only even ages

Convert the filter result to a list called even_ages

Print the even_ages list

💡 Why This Matters

🌍 Real World

Filtering data is common when you want to select only certain items from a list, like customers above a certain age or products in stock.

💼 Career

Understanding filter() helps in data cleaning, processing lists, and working efficiently with collections in many programming jobs.

1

Create the list of ages

Create a list called ages with these exact values: 12, 17, 20, 25, 30, 33, 40

Python

# Create the list called ages with the given numbers
# Your code here

Need a hint?

Use square brackets [] to create a list and separate numbers with commas.

2

Define the function to check even numbers

Define a function called is_even that takes one parameter num and returns True if num % 2 == 0, otherwise returns False

Python

ages = [12, 17, 20, 25, 30, 33, 40]
# Define the function is_even(num) below
# Your code here

Need a hint?

The % operator gives the remainder. Even numbers have remainder 0 when divided by 2.

3

Use filter() to select even ages

Use the filter() function with is_even and ages, then convert the result to a list called even_ages

Python

ages = [12, 17, 20, 25, 30, 33, 40]
def is_even(num):
    return num % 2 == 0
# Use filter() with is_even and ages, convert to list even_ages
# Your code here

Need a hint?

Remember to wrap filter() with list() to get a list.

4

Print the list of even ages

Print the list even_ages using print(even_ages)

Python

ages = [12, 17, 20, 25, 30, 33, 40]
def is_even(num):
    return num % 2 == 0

even_ages = list(filter(is_even, ages))
# Print the even_ages list
# Your code here

Need a hint?

The output should show only the even numbers from the list.