Summary
This chapter covers nested lists, showing how to create lists that contain other lists, access and modify elements using multiple indexing levels, and append new sublists to manage two-dimensional data.

General domain of usage
Storing and managing country names with their areas

Watch this video to see how nested lists work in Python. You'll learn how to create, access, and manipulate two-dimensional lists using practical examples. This will help you organize and retrieve data efficiently when working with more complex data structures.

Lists in Python can store different data types, including other lists. For example, when storing **countries and their areas**, it's more organized to use **a separate list for each country** instead of a single combined list.

# Two-dimensional list
countries_2d = [["USA", 9629091], ["Canada", 9984670], ["Germany", 357114]]

# Printing nested list
print(countries_2d)

Each country has its own nested list within the main list. In a two-dimensional list, each element is itself a list, and we access inner items using indexing. For example, in a `countries_2d` list with three sublists, `countries_2d[1]` retrieves the second sublist (indexing starts at `0`), and `countries_2d[1][0]` fetches the first item of that sublist.

# Two-dimensional list
countries_2d = [['USA', 9629091], ['Canada', 9984670], ['Germany', 357114]]

# Pull elements
print(countries_2d[1])
print(countries_2d[1][0])

Which of the following is the correct way to extract values from a nested list?

Python is an interpreted high-level general-purpose programming language. Unlike HTML, CSS, and JavaScript, which are primarily used for web development, Python is versatile and can be used in various fields, including software development, data science, and back-end development. In this course, you'll explore the core aspects of Python, and by the end, you'll be crafting your own functions!

Dive into the basics of Python, explore your workspace, and perform simple math operations. Learn how to write readable code using comments and handle both basic and advanced mathematical expressions while displaying your results.

Learn how to store and manage data in Python by working with numbers, text, and variables. Understand how to assign values, follow naming conventions, and explore different data types. Gain hands-on experience with string operations, indexing, slicing, and memory recall techniques to efficiently manipulate text in Python.

Learn how to use comparison and logical operators, work with conditional expressions, and apply membership and type comparisons. Build a strong foundation in writing programs that respond dynamically to different conditions using if/else and if/elif/else structures.

Expand your understanding of data types by learning how to group multiple attributes within a single variable. Explore lists, tuples, and dictionaries to efficiently store and manage structured data, along with essential methods for manipulation and retrieval.

Master the art of writing loops in Python—essential constructs for iterating over lists, tuples, dictionaries, and other data structures. Learn to use while and for loops effectively, explore the range function, and work with nested loops to handle complex iteration patterns.

Explore essential built-in functions in Python and take the next step by creating your own. Learn how to define functions, use conditional logic, modify existing functions, and work with lambda expressions to write efficient, reusable code.

How can you retrieve a value from a dictionary by its key?

What is the difference between a tuple and a list?

How can you access the third element in this list?


What does the `copy()` method do for lists in Python?

Is there a strict limit on how deeply you can nest tuples/lists/dictionaries in Python?

How do you update a value in a dictionary?

How would you change "green" to "yellow"?

Nested Lists in Python

Nested Lists in Python