Python List Comprehensions

Introduction

In this lab, you will step into the scenario of future space exploration, where you play the role of an interstellar communication expert. Your goal is to manipulate and process data efficiently using Python List Comprehensions, a powerful feature in Python programming.

Skills Graph

Basic List Comprehensions

In this step, you will start by learning the basics of list comprehensions and how they can be used to create and manipulate lists in Python.

Now, open the ~/project/list_comprehensions.py file and add the following code:

## list comprehensions to create a list of squared numbers
squared_numbers = [x**2 for x in range(10)]
print(squared_numbers)

Next, execute the following commands in the terminal to run the script and check the output:

python3 ~/project/list_comprehensions.py

The information below should be displayed on your terminal:

[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

Filtering with List Comprehensions

In this step, you will explore the filtering capabilities of list comprehensions in Python.

Open the list_comprehensions.py file and add the following code to filter even numbers from a list:

## list comprehensions to filter even numbers from a list
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
even_numbers = [x for x in numbers if x % 2 == 0]
print(even_numbers)

Run the script and check the output using the following commands in the terminal:

python3 ~/project/list_comprehensions.py

The information below should be displayed on your terminal:

[2, 4, 6, 8, 10]

Nested List Comprehensions

In this step, you will learn about nested list comprehensions and how they can be used to work with 2D arrays.

Open a new Python file named nested_list_comprehensions.py in the ~/project directory and add the following code:

## nested list comprehensions to create a 3x3 matrix
matrix = [[x for x in range(3)] for _ in range(3)]
print(matrix)

Execute the following commands in the terminal to run the script and check the output:

python3 ~/project/nested_list_comprehensions.py

The information below should be displayed on your terminal:

[[0, 1, 2], [0, 1, 2], [0, 1, 2]]

Summary

In this lab, you have explored the powerful capabilities of Python List Comprehensions. You have learned how to create and manipulate lists efficiently, filter elements based on conditions, and work with nested lists using list comprehensions. This hands-on experience will enhance your Python programming skills, making you well-equipped for data manipulation in future space exploration endeavors.