Python Set - intersection_update() Method

Python intersection_update() method is used to update a set with common elements only of all the sets passed in parameter of intersection_update() method.

Python set intersection_update() Method Syntax:

Syntax: set.intersection_update(set1,set2,set3,...........,set n)

Parameters: 

• One or more sets

Return: None

Note: To perform this function, we have at least two sets.

Python set intersection_update() Method Example:

s1 = {1, 2, 3}
s2 = {4, 2, 5}
s1.intersection_update(s2)
# print updated s1 set
print("After intersection_update, s1:", s1) 

Output:

After intersection_update, s1: {2}

Example 1: Set intersection_update() operation on multiple sets. 

# declare set1
set1 = {"java", "python", "c/cpp", "html"}
# declare set2
set2 = {"php", "html", "java", "R"}
# declare set3
set3 = {"java", "python", "ml", "dl"}
# declare set4
set4 = {"python", "java", "swift", "R"}
# display sets
print("set1: {}\nset2: {}\nset3: {}\nset4: {}\n".format(set1, set2, set3, set4))
# perform intersection_update operation on set1
set1.intersection_update(set2, set3, set4)
# display the result set
print("After intersection_update, set1:", set1)

Output:

set1: {'c/cpp', 'html', 'python', 'java'}
set2: {'php', 'R', 'html', 'java'}
set3: {'ml', 'dl', 'python', 'java'}
set4: {'swift', 'R', 'python', 'java'}

After intersection_update, set1: {'java'}

Example 2: Using Set intersection_update() where there are no elements in common.

Here we created two sets and there are no common elements between the sets, so the output should be empty.

# declare set1
set1 = {"java", "python", "c/cpp", "html"}
# declare set2
set2 = {"php", "cn", "dbms", "R"}
# display sets
print(set1, set2)
# perform intersection_update operation on 
# both the sets
set.intersection_update(set1, set2)
# display the result set
print(set1)

Output:

{'java', 'python', 'c/cpp', 'html'} {'R', 'cn', 'dbms', 'php'}
set()