How to find length of Set in Python?

In this article, we will see discuss how to return the length of the Set in Python. A Python set is a one-dimensional data structure that stores unique values with multiple datatypes. The built-in len() function works on sets the same way it does on lists and strings.

We can create a set using set() function. or Simply by using {}.

Syntax:

set_variable=set()

Here, we can add elements one by one using add() method.
(or)

set_variable={}

Here, we can add elements inside it separated by a comma.

If we try to add the duplicate elements into the set, they will be removed internally. So we can't expect any error in this case.

# Create a set
my_set=set()
# add 5 elements to the set
my_set.add(10)
my_set.add(20)
my_set.add(30)
my_set.add(40)
my_set.add(50)

# Create a set with 5 elements
my_set={10,20,30,40,50}

Using len() to find length of a set in Python

<a href="https://docs.python.org/3/library/functions.html#len" target="_blank" rel="noopener"

len() method in Set is used to return the total number of elements present in a Set.

Syntax:

len(set_data)

Parameter:

Here, len() takes set data structure as only one parameter.

Return:

Return an integer that represents the total number of elements in a set.

Example-1

Python Program to create a Set with 10 elements and return the total number of elements in a set.

# Create a set
my_set={"golinux-cloud",2,3,4,5,"deepak","sravan","prasad",45,67}

# Display the set
print(my_set)

# Return length of the set
print(len(my_set))

Output:

{2, 3, 4, 5, 'golinux-cloud', 67, 45, 'prasad', 'deepak', 'sravan'}
10

Explanation:

We created a set that stores integer and string type elements.

First print statement displays the elements in a set and second print statement results the total number of elements that exists in the set. As per the output, there are 10 elements in the set.

Example 2

Python Program to create a Set with 10 elements that include duplicates and return the total number of elements in a set.

# Create a set
my_set={"golinux-cloud",2,3,4,5,"golinux-cloud",2,3,4,5,}

# Display the set
print(my_set)

# Return length of the set
print(len(my_set))

Output:

{2, 3, 4, 5, 'golinux-cloud'}
5

Explanation:

We created a set that stores integer and string type elements. There are 5 duplicates in it. As we know that set will not allow duplicates.

First print statement displays the elements in a set and second print statement results the total number of elements that exists in the set. As per the output, there are 5 unique elements in the set.

Example 3

Python Program to create an empty set and add 5 elements to it. Display the total number of elements in the set.

# Create a set
my_set=set()

# add 5 elements to the set
my_set.add(10)
my_set.add(20)
my_set.add(30)
my_set.add(40)
my_set.add(50)

# Display the set
print(my_set)

# Return length of the set
print(len(my_set))

Output:

{40, 10, 50, 20, 30}
5

Explanation:

We created a set that stores 5 integer type elements.

First print statement displays the elements in a set and second print statement results the total number of elements that exists in the set. As per the output, there are 5 elements in the set.

Example 4

Python Program to create an empty set and add 5 elements that include duplicates to it. Display the total number of elements in the set.

## Create a set
my_set=set()

# add 5 elements to the set
my_set.add(10)
my_set.add(20)
my_set.add(20)
my_set.add(50)
my_set.add(50)

# Display the set
print(my_set)

# Return length of the set
print(len(my_set))

Output:

{10, 20, 50}
3

Explanation:

First print statement displays the elements in a set and second print statement results the total number of elements that exists in the set. As per the output, there are only 3 elements in the set among 5 added elements.

Summary

In this guide, we seen how to apply len() function on a set to return total number of elements with four examples. If there are duplicate elements in set, set will remove them and return the total number of unique elements.