You want to add elements to an existing list
in Python. Using a loop
is a great way that most Python developers choose. In this article, we will teach you how to add elements to a list
in a loop
in Python.
How to add elements to a list in a loop in Python
Here is how you add elements to a list
in a loop
in Python.
Add numbers in ascending order to a list
The loop in Python helps you add numbers in ascending order to a list. You will also need to use the method .append()
to push an element to the end of an existing list
. Here is the syntax:
[list] = []
[variable] = [lowest number]
for [variable] in range([integer]):
[list].append([variable])
As you see, the job is to create an empty list
. The [variable]
has the integer
value that starts from the [lowest number]
to the [integer]
value you describe in the range()
. The loop
adds numbers in ascending order to the list
.
Here is the code sample:
# Create an empty list lstNumber = [] # Create an integer number starting from 0 number = 0 # The loop adds numbers from 0 to 5 to the list for number in range(6): lstNumber.append(number) # Print the list out print(lstNumber)
The output will be:
[0, 1, 2, 3, 4, 5]
Add numbers in descending order to a list
You can also add numbers in descending order to the list. Here is the syntax:
[list] = []
[variable] = [highest integer]
for [variable] in range([variable], [lowest number], [step]):
[list].append([variable])
The [variable]
will not start from 0. Instead, it starts from the integer
that you assign. The for loop takes 3 parameters, with the [variable]
as the highest number, [lowest number]
, and the [step]
(in descending order).
See the code sample below:
# Create an empty list lstNumber = [] # Create an integer number starting from 8 number = 8 # The loop adds numbers from 8 to 0 to the list for number in range(number, -1, -1): lstNumber.append(number) # Print the list out print(lstNumber)
The output will be:
[8, 7, 6, 5, 4, 3, 2, 1, 0]
Add elements from one list to another list
You have 2 separate lists. The for loop
helps you add all elements in a list
into the other one. You still need to rely on the .append()
method to push elements to the end of the list
. The syntax is like this:
[list1] = [elements]
[list2] = [elements]
for element in [list2]:
[list1].append(element)
The for loop
adds each element from the elements of the [list2]
to the [list1]
. The [list1]
after being changed will contain elements from both [list1]
and [list2]
. You can see the code below:
# Create a List Fruit 1 lstFruit1 = ["banana", "pineapple", "lime"] print("List Fruit 1:", lstFruit1) # Create a List Fruit 2 lstFruit2 = ["orange", "apple"] print("List Fruit 2:", lstFruit2) # Use for loop to add elements from List Fruit 2 to List Fruit 1 for element in lstFruit2: lstFruit1.append(element) print("List Fruit 1 after being changed:", lstFruit1)
The output will be:
List Fruit 1: ['banana', 'pineapple', 'lime']
List Fruit 2: ['orange', 'apple']
List Fruit 1 after being changed: ['banana', 'pineapple', 'lime', 'orange', 'apple']
Summary
To summarize, we have taught you how to add elements to a list
in a loop
in Python. You can add numbers to a list in order
, or move elements from one list
to the other list
. All the work is done using Python’s built-in for loop
.

I am William Nguyen and currently work as a software developer. I am highly interested in programming, especially in Python, C++, Html, Css, and Javascript. I’ve worked on numerous software development projects throughout the years. I am eager to share my knowledge with others that enjoy programming!