How to Get the Length of a List in Python

Learn how to get the length of a list in Python with this easy-to-follow tutorial. Discover the concept, step-by-step explanations, code snippets, and expert insights. …

Updated May 22, 2023

Learn how to get the length of a list in Python with this easy-to-follow tutorial. Discover the concept, step-by-step explanations, code snippets, and expert insights.

Definition of the Concept

In programming, a list is an ordered collection of values that can be of any data type, including integers, strings, floats, etc. The length of a list refers to the number of elements it contains. In this article, we’ll explore how to get the length of a list in Python.

Step-by-Step Explanation

Here’s a simple step-by-step guide:

Create a List: First, you need to create a list using square brackets []. You can add values to the list by separating them with commas.

my_list = [1, 2, 3, 4, 5]

Use the Len() Function: To get the length of the list, you’ll use the built-in len() function. This function takes one argument – your list.

list_length = len(my_list)

Code Explanation

Let’s break down the code snippet:

my_list is the name given to our list containing integers from 1 to 5.
len() is a built-in Python function that returns the length of an object (in this case, a list).
The result of the len() function is assigned to the variable list_length.

Example Use Cases

Here are some example use cases:

Counting Items: Suppose you have a list of items and want to count how many items are in it.

shopping_list = ["apple", "banana", "cherry"]
item_count = len(shopping_list)
print(item_count)  # Output: 3

Validating Input: When validating user input, you might use the len() function to ensure that a certain number of values are provided.

user_input = ["John", "Doe", "30"]
if len(user_input) == 3:
    print("Input is valid")
else:
    print("Invalid input")

Conclusion