Intersection() function Python

In this article, we will learn about the intersection() function that can be performed on any given set. According to mathematics, intersection means finding common elements from two or more sets.

Syntax

<set_name>.intersection(<set1>, <set2>, ...)

Parameters

The intersection() method accepts one or more iterables (sets, lists, tuples) as arguments and returns their common elements.

Return Value

Returns a new set containing common elements present in all the sets passed as arguments.

Example 1: Basic Intersection

letters_1 = {'t', 'u', 'o', 'r', 'i', 'a', 'l'}
letters_2 = {'p', 'o', 'i', 'n', 't'}

# Intersection of two sets
result = letters_1.intersection(letters_2)
print("letters_1 intersection letters_2:", result)

letters_1 intersection letters_2: {'i', 'o', 't'}

Example 2: Multiple Set Intersection

letters_1 = {'t', 'u', 'o', 'r', 'i', 'a', 'l'}
letters_2 = {'p', 'o', 'i', 'n', 't'}
letters_3 = {'t', 'u'}

# Intersection of three sets
result = letters_1.intersection(letters_2, letters_3)
print("Intersection of all three sets:", result)

Intersection of all three sets: {'t'}

Example 3: Using & Operator

You can also use the & operator as an alternative to intersection() ?

numbers_1 = {1, 2, 3, 4, 5}
numbers_2 = {4, 5, 6, 7, 8}

# Using intersection() method
method_result = numbers_1.intersection(numbers_2)
print("Using intersection():", method_result)

# Using & operator
operator_result = numbers_1 & numbers_2
print("Using & operator:", operator_result)

Using intersection(): {4, 5}
Using & operator: {4, 5}

How It Works

The interpreter searches for common elements across all provided sets and returns them as a new set. The original sets remain unchanged during this operation.

Conclusion

The intersection() method finds common elements between sets, returning a new set with shared values. Use it when you need to identify overlapping data between multiple collections.