How to Use Double Colon (::) in List in Python (3 Examples)

In this article, you’ll learn how to use the double colon in a Python list.

The table of content is shown below:

Let’s start right away!

Create Example List

At the start, we will create a demo Python list that we will use in the examples below. Take a look at the following code.

my_list = [1, 2, 3, 4, 5, 6, 7, 8]
print(my_list)
# [1, 2, 3, 4, 5, 6, 7, 8]

As you can see in the previous output, we have created my_list, a list object that contains eight integers. Let’s see how to use the double colon with it!

Example 1: Use Double Colon to Slice List

The double colon is commonly used for slicing. In my_list, it can be used to extract a portion of the list based on the specific start, stop, and step values.

sliced_list = my_list[2:7:2]
print(sliced_list)
# [3, 5, 7]

In this example, we start slicing from index 2, stop at index 7, and select every second element. Thus, the resulting sliced_list contains the [3, 5, 7] values.

Example 2: Use Double Colon to Reverse List

The double colon can also be used to reverse a list. We just have to omit the start and the stop values while specifying a negative step size.

reversed_list = my_list[::-1]
print(reversed_list)
# [8, 7, 6, 5, 4, 3, 2, 1]

Here, my_list[::-1] starts from the beginning of my_list, stops at the end, and select elements with a step size of -1, resulting in reversed_list.

Example 3: Use Double Colon to Skip Elements in List

When slicing a list, we can use the double colon to skip elements.

skipped_list = my_list[::2]
print(skipped_list)
# [1, 3, 5, 7]

Take a look at the above code snippet. The slice [::2] selects elements starting from the beginning, stopping at the end, and with a step size of 2, resulting in skipped_list as you can see.

Video, Further Resources & Summary

Do you need more explanations on how to use the double colon in a list in Python? Then you should have a look at the following YouTube video of the Statistics Globe YouTube channel.

The YouTube video will be added soon.

Furthermore, you could have a look at some of the related on Statistics Globe:

• Learn Python Programming Language
• How to Compare Two Lists in Python
• Convert List to Sequence of Variables in Python
• Lists in Python (13 Examples)
• Find Substring within List of Strings in Python
• Group List into Sublists in Python

This post has shown how to use the double colon in a list in Python. In case you have additional questions, please let me know in the comments section below.

This page was created in collaboration with Paula Villasante Soriano. Please have a look at Paula’s author page to get more information about her academic background and the other articles she has written for Statistics Globe.