Python Set Operations: How to Perform Union, Intersection, Difference operations etc

Vidya Gopinath for keySkillsetVidya Gopinath for keySkillset
Vidya Gopinath for keySkillset
Python Set Operations: How to Perform Union, Intersection, Difference operations etc

Are you new to Python and interested in learning more about set operations? Or are you an experienced developer seeking to enhance your Python skills? Look no further! In this comprehensive blog post, we will explore Python set operations, including union, intersection, and more. By the end of this article, you will have a solid understanding of performing set operations in Python, enabling you to write efficient and effective code.

Furthermore, in our previous blog post on the pow() function in Python, we mentioned an upcoming Python webinar. Dates will be revealed soon!  So, follow us across our social media pages, especially our Instagram page, to keep updated.

Have you ever encountered situations where you needed to combine multiple lists or sets and perform operations on them? Perhaps you've had to find the intersection of two sets or the union of multiple lists. In such cases, you may have found yourself writing lengthy and inefficient code. Thankfully, Python provides a built-in set data type that simplifies set operations. In this post, we will explore how to leverage Python's set operations to streamline your code and enhance your coding skills.

Meanwhile, you can also check out how to use pow() function in Python in this blog.

Let’s Delve into Python Set Operators

As a Python developer, you likely work with sets frequently. Sets are incredibly useful data structures that allow you to store unique values in an unordered collection. However, working with sets is not always as straightforward as working with lists or tuples. In this blog post, we will walk you through performing set operations in Python, with a specific focus on union and intersection operations.

But before we delve into the specifics, let's discuss sets in more detail and understand why you might choose to use them. Sets are similar to lists in that they can store multiple values. However, unlike lists, sets can only contain unique values. Additionally, sets are unordered, meaning you cannot rely on a specific ordering of values within a set. Sets can be created using the set() function, and values can be added or removed using the add() and remove() methods, respectively.

Now, let's explore the most commonly used set operations: union and intersection. Union combines the values of two sets into a single set, while intersection returns a new set containing only the values that appear in both sets. Below, we will demonstrate how to perform these operations in Python:


To perform a union operation, you can use the union() method or the pipe operator (|). Here's an example:

set1 = {1, 2, 3}

set2 = {2, 3, 4}

set3 = set1.union(set2)

# OR

set4 = set1 | set2

print(set3) # Output: {1, 2, 3, 4}

print(set4) # Output: {1, 2, 3, 4}

In the example above, we have two sets (set1 and set2) that each contain some overlapping values. We then use the union() method (or the pipe operator) to combine these sets into a single set (set3 and set4).


To perform an intersection operation, you can use the intersection() method or the ampersand operator (&). Here's an example:

set1 = {1, 2, 3}

set2 = {2, 3, 4}

set3 = set1.intersection(set2)

# OR

set4 = set1 & set2

print(set3) # Output: {2, 3}

print(set4) # Output: {2, 3}

In this example, we have two sets (set1 and set2) with some overlapping values. We use the intersection() method (or the ampersand operator) to find the values that appear in both sets (set3 and set4).

Difference Set Operations in Python

The difference() set operation in Python returns a set of elements that are present in the first set and not in the second set. In other words, it subtracts the second set from the first set.

The syntax for difference() set operation is: set1.difference(set2)

where set1 is the first set and set2 is the second set.

Performing the difference() set operation in Python is quite simple. Here are the steps you need to follow:

Define the two sets you want to find the difference between:

set1 = {1, 2, 3, 4, 5}

set2 = {4, 5, 6, 7, 8}

Use the difference() function to find the difference between the two sets:

set3 = set1.difference(set2)

Print the resulting set:


#Output: {1, 2, 3}


Python set operations offer a wide range of powerful tools for manipulating sets in various ways. Through the use of operations such as union, intersection, difference, symmetric difference, subset, and superset, you can effortlessly perform complex set operations. 

This blog post aimed to enhance your comprehension of Python set operations and their practical applications. If you're eager to delve deeper into Python and programming, we encourage you to explore our comprehensive Python programming courses and tutorials. 

Embark on your journey to becoming a proficient Python developer today! You can also check out our simulation based Python Beginner course at keySkillset.

Feel free to leave any questions or comments below. Thank you for reading!

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