Python Set intersection()

The set intersection python returns a set containing the similarities of two or more sets. If the comparison is done with more than two sets, the returned set only comprises items that exist in both sets, or in all sets if the comparison is done with more than two sets. The following is the syntax:

set.intersection(set1, set2 … etc)

 intersection() ParametersFor set1, the parameter is required. For set2, it is optional. The other set is where you’ll look for goods that are the same. You are free to compare as many sets as you want. Using a comma, you can separate the sets.

 Return Value from Intersection()

The intersection() method returns set A’s intersection with all other sets (passed as argument). If intersection() is called without an argument, it returns a shallow copy of the set ( A ).]

Source

Example 1: How intersection() works?

We have three sets in the following example: X, Y, and Z. With the help of a few examples, we’ll show how to use the intersection() method. We’re looking for the set intersection Python of all three sets in the third print statement.

                    

# Set X
X = {1, 2, 3, 4, 5}

# Set Y
Y = {4, 5, 6, 7}

# Set Z
Z = {5, 6, 7, 8, 9}

# X ∩ Y
print(X.intersection(Y))

# Y ∩ Z
print(Y.intersection(Z))

# X ∩ Y ∩ Z
print(X.intersection(Y, Z))
Output
{4, 5}
{5, 6, 7}
{5}
Process finished with exit code 0

                

More Examples

1.

                    

# Python3 program for intersection() function
  
set1 = {2, 4, 5, 6} 
set2 = {4, 6, 7, 8} 
set3 = {4,6,8}
  
# union of two sets
print(“set1 intersection set2 : “, set1.intersection(set2))
  
# union of three sets
print(“set1 intersection set2 intersection set3 :”, set1.intersection(set2,set3))
Output
set1 intersection set2 :  {4, 6}
set1 intersection set2 intersection set3 : {4, 6}

                

2.

The set intersection Python method is used to intersect a set with a list in the following example:

                    

numbers = {1, 2, 3} 
scores = [2, 3, 4] 
numbers = numbers.intersection(scores) 
print(numbers)
Output
{2, 3}

                

Example 3: Set Intersection Using & operator

The set intersection operator (&) in Python allows you to connect two or more sets together:

new_set = s1 & s2 & s3 & …

The set intersection operator (&) is used to intersect the sets s1 and s2 in the following example:

                    

s1 = {‘Python’, ‘Java’, ‘C++’}
s2 = {‘C#’, ‘Java’, ‘C++’}
s = s1 & s2
print(s)


                

Output

new_set = s1 & s2 & s3 & …

Questions

How do you intersect a set in Python?

The largest set that contains all the elements that are common to both sets is the intersection of two given sets. The intersection of two given sets A and B is a set that contains all of the elements that both A and B have in common.

What is the intersection of set S and U in Python?

The intersection of set S and set U will be:

                    

S = {“a”, “b”, “c”}
U = {“c”, “d”, “a”}


                

result = S.intersection(U)

How do you find the intersection of three sets in Python?

We use set.intersection() to find the intersection of 3 sets.

                    

set1 = {1, 2}

set2 = {1, 3}

set3 = {1, 4}

intersection = set.intersection(set1, set2, set3)

print(intersection)
Output
{1}

                
			

What is set () in Python?

Set, a mathematical term for a sequence of distinct languages, is also extended in Python’s language and may be readily created using set (). The set() method is used to turn any iterable into a Set, which is a sequence of iterable items with separate elements.

Syntax: set(iterable)

Any iterable sequence, such as a list, tuple, or dictionary, can be used as a parameter.

If no element is given, it returns an empty set. The iterable of non-repeating elements has been updated as a result of the argument supplied.