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

Filter Even Numbers Using Lambda

📖 Scenario: Imagine you have a list of numbers representing daily sales counts. You want to find only the even sales numbers to analyze patterns.

🎯 Goal: Build a small program that uses a lambda function with filter() to select even numbers from a list.

📋 What You'll Learn

Create a list called sales with exact numbers: 12, 7, 9, 20, 15, 8

Create a lambda function inside filter() to select even numbers

Store the filtered result as a list called even_sales

Print the even_sales list

💡 Why This Matters

🌍 Real World

Filtering data like sales numbers helps businesses focus on specific patterns, such as even or odd counts, which can be important for inventory or promotions.

💼 Career

Understanding how to use lambda with filter() is useful for data cleaning and processing tasks common in data analysis and software development.

1

Create the sales list

Create a list called sales with these exact numbers: 12, 7, 9, 20, 15, 8.

Python

# Create the sales list with the exact numbers
# Your code here

Need a hint?

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

2

Prepare to filter even numbers

Create a variable called even_sales and assign it the result of filter() using a lambda function that checks if a number is even (divisible by 2) applied to the sales list.

Python

sales = [12, 7, 9, 20, 15, 8]
# Use filter() with a lambda to select even numbers from sales
# Your code here

Need a hint?

The lambda function should take one argument and return True if the number is even.

3

Convert filter object to list

Convert the filter object even_sales to a list by wrapping it with list() and reassign it back to even_sales.

Python

sales = [12, 7, 9, 20, 15, 8]
even_sales = filter(lambda x: x % 2 == 0, sales)
# Convert even_sales to a list
# Your code here

Need a hint?

Use list() to turn the filter result into a list you can print.

4

Print the even sales list

Print the even_sales list to display the filtered even numbers.

Python

sales = [12, 7, 9, 20, 15, 8]
even_sales = filter(lambda x: x % 2 == 0, sales)
even_sales = list(even_sales)
# Print the even_sales list
# Your code here

Need a hint?

Use print(even_sales) to show the result.