What is the purpose of a set collection type and what are its advantages?

A set in Python is a collection type designed to store unique elements without a specific order. The main advantages of sets:

• Uniqueness of elements: automatically excludes duplicates.
• Fast search and membership testing: in operations are performed in amortized O(1) time.
• Support for mathematical operations: union, intersection, difference, and symmetric difference.

Example of usage:

fruits = {'apple', 'banana', 'orange'}
fruits.add('kiwi')
print('banana' in fruits)  # True

# Union of sets
citrus = {'orange', 'lemon'}
all_fruits = fruits.union(citrus)
print(all_fruits)

Sets are useful when uniqueness and quick access to elements are important.