🚀 Day 82/150 – Set Operations (Union & Intersection) in Python

Sets are one of Python's most useful data structures for working with unique values. They support powerful mathematical operations like union and intersection, making it easy to combine or compare collections of data.

In this post, we'll explore four different ways to perform set operations in Python.

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Method 1 – Using Union (|) Operator

The | operator combines all unique elements from two sets.

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

result = set1 | set2

print(result)

Output:

{1, 2, 3, 4, 5}

Explanation:

• The union operation returns every unique element from both sets.
• Duplicate values appear only once.

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Method 2 – Using union() Method

You can also use the built-in union() method to merge sets.

set1 = {10, 20, 30}
set2 = {30, 40, 50}

result = set1.union(set2)

print(result)

Output:

{10, 20, 30, 40, 50}

Explanation:

• union() works the same as the | operator.
• It returns a new set without modifying the original sets.

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Method 3 – Using Intersection (&) Operator

The & operator returns only the elements that exist in both sets.

set1 = {"apple", "banana", "mango"}
set2 = {"banana", "grapes", "apple"}

result = set1 & set2

print(result)

Output:

{'apple', 'banana'}

Explanation:

• Only common elements are included.
• Elements that exist in only one set are ignored.

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Method 4 – Using intersection() Method

The intersection() method provides another way to find common elements.

set1 = {2, 4, 6, 8}
set2 = {1, 2, 3, 4}

result = set1.intersection(set2)

print(result)






Output:

{2, 4}

Explanation:

• Returns a new set containing only common values.
• The original sets remain unchanged.

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Comparison of Methods

Method	Best For
`	` Operator
union()	Readable union operation
& Operator	Quick intersection
intersection()	Readable intersection operation

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🔥 Key Takeaways

✅ Sets automatically remove duplicate values.

✅ Use the | operator or union() to combine unique elements from multiple sets.

✅ Use the & operator or intersection() to find common elements between sets.

✅ Set operations are fast and efficient for comparing collections of data.

✅ They are widely used in data analysis, filtering, and solving algorithmic problems.