Python List insert() Method With Examples

Python List insert() method inserts an item at a specific index in a list.

Example:

# creating a list
fruit = ["banana","cherry","grape"]
fruit.insert(1,"apple")
print(fruit)

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

Definition and Use of List insert() Method

List insert() method in Python is very useful to insert an element in a list. What makes it different from append() is that the list insert() function can add the value at any position in a list, whereas the append function is limited to adding values at the end.

It is used in editing lists with huge amount of data, as inserting any missed value in that list is made very easy with this Python function.

List insert() Method Syntax

list_name.insert(index, element)

Parameters:

• index: the index at which the element has to be inserted.
• element: the element to be inserted in the list.

Return : The insert() method returns None. It only updates the current list.

How to Insert into Python List at Index?

Using Python list insert() function you can easily insert an item to a given index in Python list.

Example

# making a list
score = [43,45,99,76]
#inserting a new score at third position
score.insert(2, 45)
#printing new list
print(score)

[43, 45, 45, 99, 76]

More Examples on Python List insert() Method

Here is another examples to depict Python list insert at index 0:

list = ['Sun', 'rises', 'in', 'the', 'east']
list.insert(0, "The")
print(list)

['The', 'Sun', 'rises', 'in', 'the', 'east']

Let's see some of the scenarios with the python list insert() function to clearly understand the workings of the insert() function.

1. Inserting an Element to a specific index into the List

Here, we are inserting 10 at the 5th position (4th index) in a Python list.

list1 = [ 1, 2, 3, 4, 5, 6, 7 ] 

# insert 10 at 4th index 
list1.insert(4, 10) 
print(list1) 

[1, 2, 3, 4, 10, 5, 6, 7]

2. Error of insert() Method

Here, we are inserting 1 at the 10th position in a Python list, we will get an error if we try to insert anything in a string because the string doesn't have attribute insert().

# attribute error
string = "1234567"

string.insert(10, 1)
print(string)

Output: 

Traceback (most recent call last):
  File "/home/2fe54bd8723cd0ae89a17325da8b2eb5.py",
   line 7, in 
    string.insert(10, 1)
AttributeError: 'str' object has no attribute 'insert'

3. Insertion in a List Before any Element

In the parse of Python List Insert here, we are inserting 13 at the 3rd position before 3 in a Python list.

# Python3 program for Insertion in a list  
# before any element using insert() method 

list1 = [ 1, 2, 3, 4, 5, 6 ]

# Element to be inserted 
element = 13 

# Element to be inserted before 3
beforeElement = 3 

# Find index
index = list1.index(beforeElement) 

# Insert element at beforeElement 
list1.insert(index, element) 
print(list1)

[1, 2, 13, 3, 4, 5, 6]

4. Inserting a Tuple into the List

Here we are inserting a tuple in a list using the insert() function in Python.

list1 = [ 1, 2, 3, 4, 5, 6 ]

# tuple of numbers
num_tuple = (4, 5, 6)

# inserting a tuple to the list
list1.insert(2, num_tuple)

print(list1)

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

5. Insert an Element to the Beginning of a List 

In this example, we are inserting the "orange" string at the 0 index of the fruits list.

fruits = ['apple', 'banana', 'cherry']
fruits.insert(0, 'orange')
print(fruits)
 # Output: ['orange', 'apple', 'banana', 'cherry']

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

6. Inserting an Element at the end of the List

In this example, we are inserting the "cherry" at the end of the list.

fruits = ['apple', 'banana', 'cherry']
fruits.insert(-1, 'orange')
print(fruits) 
# Output: ['apple', 'banana', 'orange', 'cherry']

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

7. Inserting a dictionary to a list in Python

Here we are inserting a dictionary in a list using the insert() function in Python.

my_list = [{'name': 'Alice', 'age': 30}, 
           {'name': 'Bob', 'age': 25}]
new_dict = {'name': 'Charlie', 'age': 40}

my_list.append(new_dict)

print(my_list)

[{'name': 'Alice', 'age': 30}, {'name': 'Bob', 'age': 25}, {'name': 'Charlie', 'age': 40}]

8. Python Insert List in Another List

Here we are inserting a list in a list using the insert() function in Python.

list1 = [1, 2, 3]
list2 = [4, 5, 6]

list1=list1+list2

print(list1)

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

9. Insert elements of a set to a list in Python

Here we are inserting a set in a list using the insert() function in Python.

list1 = [1, 2, 3]
s= {4,5,6}

list1.insert(3,s)

print(list1)

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

Go to the below articles to get more details information about Python Insert() Function

• Python Insert a number in string
• Python program to insert an element into sorted list

In the above article, we have discussed the Python list insert() method and its parameters with suitable examples. Python insert() function is very useful when dealing with big data.

We hope this article taught you about how to use insert() in Python.