Python set discard() Method

set.discard(element) removes an element from a set if it is present and returns None. If the element is missing, discard() does not raise KeyError.

Use remove() instead when a missing value should be treated as an error. Both methods modify the original mutable set.

my_set={'a','b','c','x','k'}
my_set.discard('x')
print(my_set)

{'c', 'a', 'k', 'b'}

Removing not available element

my_set={'a','b','c','x','k'}
my_set.discard('y')

Difference between discard() and remove()

my_set = {1, 2, 3}
my_set.discard(4)  # No error, even if 4 is not in the set
my_set.remove(4)   # Raises KeyError because 4 is not in the set

Use Case: Safely Removing Items

my_set = {'apple', 'banana', 'cherry'}
my_set.discard('banana')  # Safely removes banana
my_set.discard('grape')   # No error, even though grape is not present

Example 1: Using discard() in a Loop

my_set = {1, 2, 3, 4, 5}
elements_to_remove = [2, 6, 3]
for item in elements_to_remove:
    my_set.discard(item)  # Safely removes elements, no error if not present
print(my_set)  # Output: {1, 4, 5}

Example : Discarding Items Conditionally

my_set = {'apple', 'banana', 'cherry'}
if 'banana' in my_set:
    my_set.discard('banana')
print(my_set)  # Output: {'apple', 'cherry'}

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

About the author   Watch on YouTube

Connect: