Set Operators in Python

The set operators in Python are special symbols and functions that allow you to perform various operations on sets, such as union, intersection, difference, and symmetric difference. These operators provide a way to combine, compare, and modify sets.

Python Set Union Operator (|)

The union of two sets is a set containing all distinct elements that are in A or in B or both.

Example

set1 = {1, 2, 3}
set2 = {3, 4, 5}
set3 = {6, 8, 9}
set4 = {9, 45, 73}
union_set1 = set1.union(set2)
union_set2 = set3 | set4
print ('The union of set1 and set2 is', union_set1)
print ('The union of set3 and set4 is', union_set2)

Output

The union of set1 and set2 is {1, 2, 3, 4, 5}
The union of set3 and set4 is {73, 6, 8, 9, 45}

Python Set Intersection Operator (&)

The intersection of two sets consists of all elements that are common to both.

Example

set1 = {1, 2, 3}
set2 = {3, 4, 5}
set3 = {6, 8, 9}
set4 = {9, 8, 73}
intersection_set1 = set1.intersection(set2)  
intersection_set2 = set3 & set4
print ('The intersection of set1 and set2 is', intersection_set1)
print ('The intersection of set3 and set4 is', intersection_set2)

Output

The intersection of set1 and set2 is {3}
The intersection of set3 and set4 is {8, 9}

Python Set Difference Operator (-)

The difference between two sets consists of elements present in the first set but not in the second set.

Example

set1 = {1, 2, 3}
set2 = {3, 4, 5}
set3 = {6, 8, 9}
set4 = {9, 8, 73}
difference_set1 = set1.difference(set2)
difference_set2 = set3 - set4
print ('The difference between set1 and set2 is', difference_set1)
print ('The difference between set3 and set4 is', difference_set2)

Output

The difference between set1 and set2 is {1, 2}
The difference between set3 and set4 is {6}

Python Set Symmetric Difference Operator (^)

The symmetric difference of two sets consists of elements that are present in either set but not in both sets.

Example

set1 = {1, 2, 3}
set2 = {3, 4, 5}
set3 = {6, 8, 9}
set4 = {9, 8, 73}
symmetric_difference_set1 = set1.symmetric_difference(set2)  
symmetric_difference_set2 = set3 ^ set4
print ('The symmetric difference of set1 and set2 is', symmetric_difference_set1)
print ('The symmetric difference of set3 and set4 is', symmetric_difference_set2)

Output

The symmetric difference of set1 and set2 is {1, 2, 4, 5}
The symmetric difference of set3 and set4 is {73, 6}

Python Subset Testing Operation

You can check whether one set is a subset of another using the issubset() function or the <= operator.

Example

set1 = {1, 2}
set2 = {1, 2, 3, 4}
set3 = {64, 47, 245, 48}
set4 = {64, 47, 3}
is_subset1 = set1.issubset(set2)  
is_subset2 = set3 <= set4
print ('set1 is a subset of set2:', is_subset1)
print ('set3 is a subset of set4:', is_subset2)

Output

set1 is a subset of set2: True
set3 is a subset of set4: False