Python – Multiple Sets Intersection

In this article given List of sets, the task is to write a Python program to perform their intersection.

Examples:

Input : test_list = [{5, 3, 6, 7}, {1, 3, 5, 2}, {7, 3, 8, 5}, {8, 4, 5, 3}]

Output : {3, 5}

Explanation : 3 and 5 is present in all the sets.

Input : test_list = [{5, 3, 6, 7}, {1, 3, 5, 2}, {7, 3, 8, 5}, {8, 4, 5, 4}]

Output : {5}

Explanation : 5 is present in all the sets.

Method #1 : Using intersection() + * operator

In this, we perform tasks of getting intersection using intersection() and * operator is used to pack all the sets together.

Python3

# Python3 code to demonstrate working of
# Multiple Sets Intersection
# Using intersection() + * operator

# initializing list
test_list = [{5, 3, 6, 7}, {1, 3, 5, 2}, {7, 3, 8, 5}, {8, 4, 5, 3}]

# printing original list
print("The original list is : " + str(test_list))

# getting all sets intersection using intersection()
res = set.intersection(*test_list)

# printing result
print("Intersected Sets : " + str(res))

Output:

The original list is : [{3, 5, 6, 7}, {1, 2, 3, 5}, {8, 3, 5, 7}, {8, 3, 4, 5}]

Intersected Sets : {3, 5}

Method #2 : Using reduce() + and_ operator

In this, we perform task of intersection using and_ operator and reduce() does the task of getting all the sets packed together for required operation.

Python3

# Python3 code to demonstrate working of
# Multiple Sets Intersection
# Using reduce() + and_ operator
from operator import and_
from functools import reduce

# initializing list
test_list = [{5, 3, 6, 7}, {1, 3, 5, 2}, {7, 3, 8, 5}, {8, 4, 5, 3}]

# printing original list
print("The original list is : " + str(test_list))

# getting all sets intersection using and_ operator
res = set(reduce(and_, test_list))

# printing result
print("Intersected Sets : " + str(res))

Output:

The original list is : [{3, 5, 6, 7}, {1, 2, 3, 5}, {8, 3, 5, 7}, {8, 3, 4, 5}]

Intersected Sets : {3, 5}