Automatic Duplicate Removal

The automatic duplicate removal behavior of sets is one of their most powerful and useful features. Sets eliminate duplicates both during creation and when adding new elements. This happens silently, without errors or warnings. Understanding this behavior allows you to write cleaner, more concise code. Even though we specified "Alice" three times and "Bob" twice in the set literal, the resulting set contains each name exactly once. Python processes the elements in order, adding each one to the set. When it encounters an element that already exists in the set, it simply skips it. This behavior is consistent and predictable. This same deduplication happens when you add elements to an existing set. If you add an element that already exists, the set remains unchanged. No error is raised, and t