Python – Join Sets

Python offers a robust set of methods for performing operations on multiple sets. These include union(), update(), intersection(), difference(), and symmetric_difference(). Each method has its unique application depending on the desired outcome when working with set data structures.

1. Union of Sets

The union() method creates a new set containing all unique elements from the involved sets.

set1 = {"a", "b", "c"}
set2 = {1, 2, 3}
set3 = set1.union(set2)
print(set3)

Alternatively, you can use the | operator:

set3 = set1 | set2
print(set3)

Joining Multiple Sets

You can pass multiple sets to the union() method by separating them with commas:

set1 = {"a", "b", "c"}
set2 = {1, 2, 3}
set3 = {"John", "Elena"}
set4 = {"apple", "bananas", "cherry"}
result = set1.union(set2, set3, set4)
print(result)

Using | for multiple sets:

result = set1 | set2 | set3 | set4
print(result)

Union with Other Data Types

The union() method supports merging with tuples or lists:

x = {"a", "b", "c"}
y = (1, 2, 3)
z = x.union(y)
print(z)

Note: The | operator does not support other data types.

2. Update Method

update() merges elements from one set into another, modifying the original set.

set1 = {"a", "b", "c"}
set2 = {1, 2, 3}
set1.update(set2)
print(set1)

Note: Duplicate values are automatically excluded.

3. Intersection of Sets

intersection() returns a new set containing only elements that appear in all involved sets.