How do different set implementations compare in Python?

How do different set implementations compare in Python?

In Python, the main set implementations are set, frozenset, and OrderedDict (for maintaining order). The set is mutable, while frozenset is immutable. Both provide average O(1) time complexity for lookups, but frozenset cannot be modified after creation.

What are the advantages of using frozenset over set?

The main advantages of using frozenset are its immutability, which makes it hashable and usable as a key in dictionaries, and its ability to ensure that the data remains constant throughout its lifetime.

Are there any performance differences between them?

Yes, set is generally faster for operations that modify the set, like adding or removing elements. However, frozenset can be more efficient for read-only operations since it has a fixed size.

When should I use OrderedDict instead of set?

Use OrderedDict when you need to maintain the order of elements while also having unique keys. It's useful for scenarios where the order of insertion matters.