Python List extend() Method

The Python List extend() method adds items of an iterable (list, tuple, dictionary, etc) at the end of a list.

Example

Output

['Audi', 'BMW', 'Jaguar', 'Maruti', 'Tata']

List extend() Syntax

list_name.extend(iterable)

Parameters:

• iterable: Any iterable (list, set, tuple, etc.)

Returns

Python List extend() returns none.

What is Python List extend() method?

List extend() function is an in-built function of Python that extends a list by adding values of an iterable (list, tuple, string, etc) at the end of that list.

List extend() function is very useful when you don’t want to add values from an iterable individually. It saves a lot of time and effort when adding values from an iterable.

How to use list extend() method in Python

You can easily extend a list using extend() function. let’s see how to extend a list in Python with an example for better understanding.

Example: In this example, we can see how to extend a list in Python.

Output

['apple', 'milk', 'cookies', 'diaper', 'baby oil']

More Examples on List extend()

Let’s see some of the different scenarios where we use list extend() method.

1. Extend list with another List

The list.extend() method is equivalent to list[len(list):] = iterable. The list.extend() is Python’s built-in function that loops through the provided iterable, appending the elements to the end of the current list. Here we are extending a list with another list’s elements with extend() function.

Output

[1, 2, 3, 4, 5, 6]

2. Extend List with Tuple

This code extends a list of an element with the element of a tuple with extend() in Python.

Output

['geeks', 'for', 'geeks', 'DSA', 'Java']

3. Extend List with a Set

This code extends a list of an element with the element of set with extend() in Python.

Output

['geeks', 'for', 'geeks', 'Flutter', 'Android']

4. Extend List with a String

A string is iterable, so if you extend a list with a string, you’ll append each character as you iterate over the string.

Output

['geeks', 'for', 6, 0, 4, 1, 'g', 'e', 'e', 'k', 's']

Python list Extend with + Operator

We can also extend a list without using the extend() function. You can see this with an example below.

In this code, We are extending the list with the + operator in Python.

Output

['apple', 'banana', 'cherry', 'orange', 'grape']

Python list extend() vs append()

append() and extend() functions of lists add values at the end of the list, but they are very different. append() can only add one value at a time whereas extend() can add multiple values from an iterable to a list.

Example:

In the example, we have the list of fruits initially containing two elements: apple and banana. When we use the extend() method, the elements from more_fruits are appended individually to the list of the fruits, resulting in [‘apple’, ‘banana’, ‘cherry’, ‘orange’].

However, when we use the append() method, the more_fruits list itself is added as a single element at the end of the fruits list. 

Output

['apple', 'banana', 'cherry', 'orange']
['apple', 'banana', ['cherry', 'orange']]

Read more: Difference between Append, Extend, and Insert in Python.

We have discussed the definition, syntax and different uses of Python list extend() method. extend() method is very important operation on lists, and can save you a lot of time from manually extending a list.

Read Other Python List Methods

Similar Article on List extend:

• Extending a list in Python (5 different ways)
• append() and extend() in Python