By Minh Vu
Updated Feb 08, 2026
Minh Vu
Software Engineer
Hi 👋, I'm a software engineer specializing in backend systems, distributed systems, and scalable architecture. My blog shares practical tutorials based on 3+ years of experience. LeetCode 1756 (Top 10%). Actively seeking SDE roles — let's get in touch!
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![Figure: Python List [-1], [:n], [-n:], [::-1] Explained](https://ik.imagekit.io/dminhvu/assets/python-list-1-n-n-1-explained/thumbnail.png?tr=f-webp,w-768 "Python List [-1], [:n], [-n:], [::-1] Explained")
You may see some code in Python like list[-1], list[:n], list[-n:], or list[::-1]. What do they mean? In this article, we will learn more about this technique which is called list slicing.
In simple words, the meaning of those expressions is:
list[-1]: get the last element of the listlist[:n]: get the first n elements of the listlist[-n:]: get the last n elements of the listlist[::-1]: reverse the listKeep reading to understand more how list slicing works.
In Python, list slicing is a technique to get a subset of a list using indices. The syntax is list[start:end:step] where:
start: the index of the first element in the subset (inclusive), default to 0end: the index of the last element in the subset (exclusive), default to len(list)step: the step size to get elements in the subset, default to 1For example, numbers[1:10:3] means to get all numbers from index 1 to 10 with a step size of 3.
Let's make that example more clear.
numbers = [2, 1, 0, 3, 5, 6, 8, 9, 7, 4] print(numbers[1:10:3]) # Output: [1, 5, 9]
We have a list numbers with 10 elements. So numbers[1:10:3] are elements at 1, 4, and 7 indices, which are 1, 5, and 9, respectively.
list[-1] means to get the last element of the list. It is equivalent to list[len(list) - 1].
numbers = [2, 1, 0, 3, 5, 6, 8, 9, 7, 4] print(numbers[-1]) # Output: 4
list[:n] means to get the first n elements of the list. It is equivalent to list[0:n].
If n is greater than the length of the list, it will return all elements of the list.
numbers = [2, 1, 0, 3, 5, 6, 8, 9, 7, 4] print(numbers[:3]) # Output: [2, 1, 0] print(numbers[:0]) # Output: [] print(numbers[:100]) # Output: [2, 1, 0, 3, 5, 6, 8, 9, 7, 4]
list[-n:] means to get the last n elements of the list. It is equivalent to list[len(list) - n:].
numbers = [2, 1, 0, 3, 5, 6, 8, 9, 7, 4] print(numbers[-3:]) # Output: [9, 7, 4] print(numbers[-5:]) # Output: [6, 8, 9, 7, 4]
list[::-1] means to reverse the list. It is equivalent to list[len(list) - 1:0:-1].
Let's break it down:
len(list) - 1: the index of the last element of the list0: the index of the first element of the list-1: the step size to get elements in the subsetSo, in word, it means to go backward from the last element to the first element with a step size of 1.
numbers = [2, 1, 0, 3, 5, 6, 8, 9, 7, 4] print(numbers[::-1]) # Output: [4, 7, 9, 8, 6, 5, 3, 0, 1, 2]
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