How to Divide All Elements of a List by a Number in Python?

If you’re a fresh developer and interested in learning several approaches to divide all elements of list in Python by a constant or number, continue reading this article for comprehensive information and clear illustrations.

This article will guide you through dividing all list elements in Python. In this article, first of all, we’ll discuss what a list is in Python and how it works. Furthermore, we’ll discuss the four different methods to divide all elements of a list. 

Finally, we will explore which method to use according to the scenario. Let’s dig deeper into the topic to find more detailed and deeper information.

What is a List in Python?

In Python, lists are like dynamic arrays, which are used to store multiple items in a single variable. It is one of the built-in data types provided by Python. It is a sequence data type that stores the collection of data. We can create a list by enclosing elements in square brackets [] and separating elements by commas(,). 

For example:

Code

mylist=[10, 20, 30, 50]

# We can easily access its elements by using the index number 

print(mylist[1])

# We can print all elements of the list by just writing the list name

print(mylist)

Output

20

[10, 20, 30, 50]

Some useful methods of the list are len(), append(), and insert(), which we use in solving the mystery of “dividing all elements of the list“. The Len() function tells us the length of our list. We can insert an element in a specific index with the help of insert(). The append() function is used to append an element at the end of the list.

One of the best features of the list is that assigning it to another list will not make a copy of the list. Instead, both variable points to the same list. 

For example:

Code

mylist=[10, 20, 30, 50]

print("Elements of mylist:", mylist)

# Assign mylist to newlist

newlist=mylist

# Changing the element of newlist will change both lists

# Means both list points to the same memory location

newlist[1]=40

print("Elements of mylist after changing newlist:",mylist)

Output

Elements of mylist: [10, 20, 30, 50]

Elements of mylist after changing newlist: [10, 40, 30, 50]

How to Divide all Elements of a List in Python

We have several ways to divide an integer with all list elements. Some of them are:

1. Using Loop to create a new list
2. Using Loop to modify the same list
3. Using List comprehension
4. Using lambda and map function

Method 1: Using Loop Create New List

We can create a new list and store each element of the existing list after dividing it with an integer with the help of a loop.

Code

mylist=[10, 20, 30, 50]

print("Elements of mylist:", mylist)

myint=10

newlist=[]

for elements in mylist:

    newlist.append(elements/myint)

print(newlist)

Output

Elements of mylist: [10, 20, 30, 50]

[1.0, 2.0, 3.0, 5.0]

We can also use a while loop to store all the divided elements in the new list.

Code

mylist=[10, 20, 30, 50]

print("Elements of mylist:", mylist)

myint=10

newlist=[]

counter=0

while counter < len(mylist):

    newlist.append(mylist[counter]/myint)

    counter = counter + 1

print("After division:",newlist)

Method 2: Using Loop Modify Same List

Sometimes we have limited storage and have to change the same list, so in that case, we have to use the insert and remove method of the list, not use a new list and modify the same list. 

Let’s understand this concept with the help of a simple example:

Code

mylist=[10, 20, 30, 50]

print("Elements of mylist:", mylist)

myint=10

counter=0

while counter < len(mylist):

    # insert a new element on the same list by dividing it with an integer

    mylist.insert(counter,mylist[counter]/myint)

    counter = counter + 1

    # Remove divided element from our list

    mylist.remove(mylist[counter])

print("After division:",mylist)

Output

Elements of mylist: [10, 20, 30, 50]

After division: [1.0, 2.0, 3.0, 5.0]

Method 3: Using List Comprehension Method

Using the comprehension method is one of the simplest ways to divide all elements of the list and create a new list by just a single line. Now let’s understand this concept with the help of a simple example:

Code

mylist=[10, 20, 30, 50]

print("Elements of mylist:", mylist)

myint=10

# All elements to newlist after dividing it with myint

newlist = [element/myint for element in mylist]

print("After division:",newlist)

Output

Elements of mylist: [10, 20, 30, 50]

After division: [1.0, 2.0, 3.0, 5.0]

Method 4: Using Lambda and Map

We can use the anonymous lambda and map function to create a new list by dividing each element by an integer. Now let’s understand this concept with the help of a simple example:

Code

list1=[100, 200, 300, 500]

print("Elements of list:", list1)

no=10

# using lambda and map function

list2 = list(map(lambda element: element/no, list1))

# assigning reference of list2 to list1

list1 = list2

print("After division:",list1)

Output

Elements of the list: [100, 200, 300, 500]

After division: [10.0, 20.0, 30.0, 50.0]

Conclusion

After this debate, we come to the point where we can easily divide all elements of a list with the help of any of the above-mentioned methods. All these methods are used in different situations, e.g., If storage is not our problem, then we can create a new list by using a loop, list comprehension, or lambda function, but if storage matters, then we use a loop to modify the same list. List comprehension is the easiest method to use of all of these four methods.

Here is a quick recap of the topics discussed in the article:

1. What is a list in Python, and how to divide all elements of list in Python?
2. Divide all elements of a list by creating a new list with the help of a loop 
3. Divide all elements of a list by modifying the existing list with the help of a loop
4. Divide all elements of a list by List comprehension
5. Divide all elements of a list by using lambda and maps function

If you find this article helpful, do share it with your friends 🧑‍🤝‍🧑 and Let us know which method works best for you in the comments section below. Happy Coding!