Remove first element from list in Python

Prepend Elements to Lists in Python

Last Updated : 17 Dec, 2024

In Python, prepending means adding elements to the beginning of a list. We can think of it as putting something at the front of a queue. In this article, we will explore various methods to prepend elements to lists in Python. The insert() method to add an element at a specific position in a list. To add an element at the beginning, we can specify position 0.

Python

a = [2, 3, 4]

# Adds 1 at the beginning of the list
a.insert(0, 1)
print(a)

Output

[1, 2, 3, 4]

Other methods that we can use to prepend elements to a list are:

Table of Content

Using + Operator
Using collections.deque

Using + Operator

Another simple method is to use the + operator to concatenate lists. We can create a new list with the element to be prepended and then join it with the original list.

Python

a = [2, 3, 4]
b = [1]

# Adds 1 at the beginning by joining two lists
a = b + a  
print(a)

Output

[1, 2, 3, 4]

Using collections.deque

This is one of the most efficient ways to prepend elements if we are working with lists that change frequently. The deque (double-ended queue) is optimized for appending and prepending elements quickly.

Python

from collections import deque

a = deque([2, 3, 4])

# Adds 1 at the beginning of the deque
a.appendleft(1)  
print(a)

Output

deque([1, 2, 3, 4])

Remove first element from list in Python

S

subramanyasmgm

Improve

Article Tags :

Practice Tags :

Similar Reads

Python | Preceding element tuples in list

Sometimes, while working with Python list, we can have a problem in which we need to construct tuples, with the preceding element, whenever that element matches a particular condition. This can have potential application in day-day programming. Let's discuss a way in which this task can be performed

How to add Elements to a List in Python

In Python, lists are dynamic which means that they allow further adding elements unlike many other languages. In this article, we are going to explore different methods to add elements in a list. For example, let's add an element in the list using append() method: [GFGTABS] Python a = [1, 2, 3] a.ap

Print lists in Python

Printing a list in Python is a common task when we need to visualize the items in the list. There are several methods to achieve this and each is suitable for different situations. In this article we explore these methods. The simplest way of printing a list is directly with the print() function: [G

Remove first element from list in Python

The task of removing the first element from a list in Python involves modifying the original list by either deleting, popping, or slicing the first element. Each method provides a different approach to achieving this. For example, given a list a = [1, 2, 3, 4], removing the first element results in

Filter Python list by Predicate in Python

A predicate is a function that returns either True or False for a given input. By applying this predicate to each element of a list, we can create a new list containing only the elements that satisfy the condition. Let's explore different methods to filter a list based on a predicate. Using list com

Get Index of Multiple List Elements in Python

In Python, retrieving the indices of specific elements in a list is a common task that programmers often encounter. There are several methods to achieve this, each with its own advantages and use cases. In this article, we will explore some different approaches to get the index of multiple list elem

Remove Last Element from List in Python

Given a list, the task is to remove the last element present in the list. For Example, given a input list [1, 2, 3, 4, 5] then output should be [1, 2, 3, 4]. Different methods to remove last element from a list in python are: Using pop() methodUsing Slicing TechniqueUsing del OperatorUsing Unpacking

Map vs List comprehension - Python

List comprehension and map() both transform iterables but differ in syntax and performance. List comprehension is concise as the logic is applied in one line while map() applies a function to each item and returns an iterator and offering better memory efficiency for large datasets. List comprehensi

Pass a List to a Function in Python

In Python, we can pass a list to a function, allowing to access or update the list's items. This makes the function more versatile and allows us to work with the list in many ways. Passing list by Reference When we pass a list to a function by reference, it refers to the original list. If we make an

Apply function to each element of a list - Python

Applying a function to a list means performing a specific operation or transformation on each element of the list. For instance, we might want to multiply each element of a list by a constant or perform any custom operation using a function. In this article, we will explore various ways to Apply fun