What is the purpose of sets in Python?

In Python, a set is a collection of unique and unordered data. Its main purpose includes the following points:

1. De-duplication: Elements in a set cannot be repeated, so it can be used to remove duplicate elements from lists, tuples, and other iterable objects. By converting the iterable object into a set and then converting it back, duplicate elements can be removed.
2. Membership test: You can use the “in” keyword to determine if an element is in the set, and due to sets being implemented through hash tables, the speed of the membership test is very fast.
3. Mathematical operations: sets support various mathematical operations such as union, intersection, and difference. These operations can be performed using mathematical operators or their corresponding methods, making it very convenient for processing set operations.
4. Efficient search: Due to the use of a hash table in implementing sets, the time complexity for searching elements is O(1), much faster than linear search in lists or tuples.
5. Iteration: You can use a for loop to iterate through the elements in a set.

It is important to note that sets are unordered, so you cannot access elements within them by index. If you need an ordered collection, you can use the sorted() function to sort the set, or use an ordered data structure such as a list.