Python List insert()

Python List insert() method inserts a given element at a given index in a list using Python. 

Example

Python insert() methods with string in Python.

Python3

lis = ['Geeks', 'Geeks']
lis.insert(1, "For")
print(lis)

Output:

['Geeks', 'For', 'Geeks']

Python List insert() Syntax

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.

Returns: Does not return any value.

List insert() in Python Example

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.

Python3

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

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

Output:

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

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().

Python3

# 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'

Insertion in a List Before any Element

Here, we are inserting 13 at the 3rd position before 3 in a Python list.

Python3

# 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)

Output:

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

Inserting a Tuple into the List

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

Python3

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)

Output:

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

Add 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.

Python3

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

Output :

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

Inserting an Element at the end of the List using th

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

Python3

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

Output :

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

Inserting Dictionary into a List

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

Python3

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

my_list.append(new_dict)

print(my_list)

Output :

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

Inserting a List into a List

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

Python3

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

list1=list1+list2

print(list1)

Output :

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

Inserting a Set into a List

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

Python3

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

list1.insert(3,s)

print(list1)

Output :

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