Python Set intersection_update()

The intersection of two or more sets is the set of elements which are common to all sets.

To learn more, visit Python set Intersection.

The syntax of intersection_update() is:

A.intersection_update(*other_sets)

intersection_update() Parameters

The intersection_update() method allows an arbitrary number of arguments (sets).

Note: * is not a part of the syntax. It is used to indicate that the method allows an arbitrary number of arguments.

Return Value from Intersection_update()

This method returns None (meaning it does not have a return value). It only updates the set calling the intersection_update() method.

For example:

result = A.intersection_update(B, C)

When you run the code,

• result will be None
• A will be equal to the intersection of A, B, and C
• B remains unchanged
• C remains unchanged

Example 1: How intersection_update() Works?

A = {1, 2, 3, 4}
B = {2, 3, 4, 5}

result = A.intersection_update(B)

print('result =', result)
print('A =', A)
print('B =', B)

Output

result = None
A = {2, 3, 4}
B = {2, 3, 4, 5}

Example 2: intersection_update() with Two Parameters

A = {1, 2, 3, 4}
B = {2, 3, 4, 5, 6}
C = {4, 5, 6, 9, 10}

result = C.intersection_update(B, A)

print('result =', result)
print('C =', C)
print('B =', B)
print('A =', A)

Output

result = None
C = {4}
B = {2, 3, 4, 5, 6}
A = {1, 2, 3, 4}