? Python Join Sets

⚡ Quick Overview

In Python, you can join (combine) sets to create a new set that contains all unique elements from the given sets. The most common ways to join sets are:

union() method
| (pipe) operator
update() method to modify an existing set in place

? Key Concepts

Sets automatically remove duplicate elements.
union() returns a new set and does not change the original sets.
| operator is a shorthand way of doing union.
update() adds all elements from another set (or iterable) into the original set.
You can join sets with any iterable (lists, tuples, sets, etc.).

? Syntax and Theory

Union using method:
result = set1.union(set2)
Union using operator:
result = set1 | set2
Update in place:
set1.update(set2)

? Code Examples

? Union of two sets using union() and |

set1 = {1, 2, 3}
set2 = {3, 4, 5}

# Using union()
joined_set = set1.union(set2)
print(joined_set)  # {1, 2, 3, 4, 5}

# Using |
joined_set2 = set1 | set2
print(joined_set2)  # {1, 2, 3, 4, 5}

? Update one set with elements from another

set1 = {1, 2, 3}
set2 = {3, 4, 5}

# Update set1 with all elements of set2
set1.update(set2)
print(set1)  # {1, 2, 3, 4, 5}

? Output and Explanation

? What happens when you join sets?

In the first example, set1.union(set2) and set1 | set2 both create a new set containing all unique elements from set1 and set2.

The output will look like:

{1, 2, 3, 4, 5}

In the second example, set1.update(set2) modifies set1 directly. After the update, set1 becomes:

{1, 2, 3, 4, 5}

Notice how the duplicate element 3 appears only once in the final set, because sets automatically remove duplicates.

? Tips and Best Practices

Use union() when you need a new combined set without changing the originals.
Use update() when you want to add elements directly into an existing set.
Remember that sets do not preserve order and do not allow duplicates.
You can pass any iterable (like a list or tuple) to update(), not just another set.

? Try It Yourself

Create two sets of numbers and join them using union(). Print the result.
Repeat the same using the | operator and compare the output.
Create a set and then call update() with a list of new values. Check how the set changes.
Experiment with sets that have overlapping elements and observe how duplicates are handled.