Convert List to Set

Sometimes, because of the differences in how elements are stored in a list, or set, we may need to convert a given List of elements into a Set in Python.

In this tutorial, we shall learn how to convert a list into set. There are many ways to do that. And we shall discuss the following methods with examples for each.

Use set() builtin function.
Unpack List inside curly braces.

1. Convert List to Set using set() builtin function

set() builtin function can take any iterable as argument, and return a set object formed using the elements from the given iterable.

In the following program, we take a list of strings, and convert it into a set.

Python Program

# Take a list of elements
list1 = ['apple', 'banana', 'cherry']

# Convert list into set
output = set(list1)

print(f'Set : {output}')
print(type(output))

Output

Set : {'apple', 'banana', 'cherry'}
<class 'set'>

If there are any duplicates in the given list object, they are ignored. A set can contain only unique elements.

In the following program, we take a list of strings where some of the elements are repeated inside the list (duplicates), and convert it into a set.

Python Program

# Take a list of elements
list1 = ['apple', 'banana', 'cherry', 'banana', 'cherry']

# Convert list into set
output = set(list1)

print(f'Set : {output}')
print(type(output))

Output

Set : {'cherry', 'apple', 'banana'}
<class 'set'>

2. Convert List to Set by unpack List inside Curly Braces

We can also unpack the items of List inside curly braces to create a set.

In the following program, we have a list of strings, and we shall unpack the elements of this list inside curly braces.

Python Program

# Take a list of elements
list1 = ['apple', 'banana', 'cherry']

# Unpack list items and form set
output = {*list1}

print(f'Set : {output}')
print(type(output))

Output

Set : {'cherry', 'banana', 'apple'}
<class 'set'>

Summary

In this tutorial of Python Examples, we learned how to convert a Python List into a Set in different ways, with the help of well detailed example programs.