Sets & Mathematical Set Operations
Discover Sets to eliminate duplicates instantly and perform blazing-fast mathematical operations like union and intersection.
Intermediate
5 min read
The Power of Uniqueness
A Set in Python is an unordered collection of entirely unique elements. Sets do not record element positions (indexes), meaning you cannot do `myset[0]`.
Instantly Removing Duplicates
The most common use case for a set in the real world is taking a messy list full of duplicates and cleaning it instantly by casting it to a set.
emails = ["a@a.com", "b@b.com", "a@a.com", "c@c.com"]
unique_emails = list(set(emails))
# Result: ["a@a.com", "b@b.com", "c@c.com"]Mathematical Superpowers
Sets excel at relational mathematics. Let's say you have two sets of friends on different social networks, and you want to analyze them:
fb_friends = {"Alice", "Bob", "Charlie"}
ig_friends = {"Charlie", "David", "Alice"}
# Union (|): Everyone from both lists combined
all_friends = fb_friends | ig_friends
# Intersection (&): Friends who are on BOTH platforms
mutual_friends = fb_friends & ig_friends
# Difference (-): Friends on FB but NOT on IG
fb_only = fb_friends - ig_friends