Orderly Set

Orderly Set is a Python package providing several implementations of ordered set data structures, including `OrderlySet`, `StableSet`, `StableSetEq`, `OrderedSet`, and `RoughMaxSizeSet`. These implementations combine the uniqueness of a set with the order-preserving characteristics of a list or sequence, offering various performance trade-offs for operations such as insertion, deletion, membership testing, and index lookups. The library is actively maintained, with its current version being 5.5.0, and receives regular updates as evidenced by its GitHub release history.