Python Sets

A Set is an unordered collection of unique items. Sets automatically remove duplicates and are perfect for membership testing and mathematical set operations.

Why Use Sets?

Creating Sets

Set Characteristics

Adding and Removing Items

Membership Testing (Very Fast!)

Set Operations (Mathematical)

Union (Combine Sets)

Intersection (Common Items)

Difference (Items in One Set Only)

Symmetric Difference (Items in Either, Not Both)

Set Relationships

Removing Duplicates

Frozen Sets (Immutable Sets)

Practical Applications

Coding Challenge: Tag System 🏷️

Quiz

Key Takeaways

✅ Sets store unique items only - duplicates are automatically removed.
✅ Sets are unordered - items have no specific order.
✅ Use {} or set() to create sets, but set() for empty sets.
✅ Set operations: | (union), & (intersection), - (difference), ^ (symmetric difference).
✅ Sets are very fast for membership testing (in operator).
✅ Frozensets are immutable and can be used as dictionary keys.

What's Next?

In the next lesson, we'll explore Dictionaries - powerful key-value pair collections for storing and retrieving data efficiently.

Keep coding! 🚀