When would you use a list, tuple, set, or dictionary in Python?

Use a list for an ordered sequence that you intend to modify and a tuple for a fixed sequence or record-like grouping. A set stores distinct hashable elements and supports membership and set operations, but it does not provide sequence indexing. A dictionary maps unique hashable keys to values and preserves insertion order in mode Python. Lists and dictionaries are mutable; a tuple’s elements cannot be reassigned, although a tuple can reference a mutable object. Choose the collection according to operations and meaning, not just its literal syntax.