Python: Dictionaries and Sets
2026-02-21 23:42 Diff
https://hexlet.io/courses/python-dicts/lessons/modification-of-sets/theory_unit

Sets in Python are mutable. You can add and remove elements from them using the add, discard and remove methods:

When reading the code in this example, you may have noticed that adding extra elements with add and discarding non-existent ones with discard does not lead to an error. Sets are so patient. However, calling the remove method with a non-existent element results in an error.

Copying and clearing sets

Since sets are changeable, it often becomes necessary to make a copy before changing the original. They are like dictionaries, so they do not support obtaining a slice. We have to use the copy method to copy, which creates a surface copy of the set:

To clear the set without creating it again, you can use the clear method: