Python Data Structures and Algorithms Tutorial

Nested Lists

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In this tutorial, we'll learn about "Nested Lists" in Python.

What Are Nested Lists?

Nested lists are lists that contain other lists as their elements.
They allow us to create a list of lists or a matrix where each element can be accessed using multiple indices.

Creating Nested Lists

Example:

Nested_list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

Accessing Elements:

Accessing elements in a nested list involves using multiple indices.
We can use the first index to access the outer list and the second index to access the inner list.

Example:

Nested_list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
value = Nested_list[1][2]
print(value)

Output:

Modifying Elements:

Example:

Nested_list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
Nested_list[0][1] = 10
print(Nested_list)

Output:

[[1, 10, 3], [4, 5, 6], [7, 8, 9]]

Iterating through Lists:

We can use nested loops to iterate through all elements in a nested list. Outer loop for the outer list and inner loop for the inner lists.

Example:

Nested_list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
for lst in Nested_list:
    for j in lst:
        print(j)

Output:

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