Which collection is immutable by design in Python?

Which collection is immutable by design in Python?

• A. List
• B. Tuple
• C. Dictionary
• D. Set

Answer: (B)

Immutability means a container’s contents can’t be changed after it’s created. The collection designed to be immutable in Python is the tuple. When you make a tuple, its sequence of elements is fixed: you can’t reassign an item, insert or remove elements, or sort it in place. If you want different contents, you create a new tuple, for example by concatenation or slicing. This immutability is why tuples are suitable as dictionary keys or as elements of sets—their value won’t change in a way that would affect hashing. Keep in mind that if a tuple contains mutable objects (like a list), those inner objects can be changed, but the tuple itself won’t reconfigure which objects it references or how many there are. In contrast, lists, dictionaries, and sets are mutable; they allow in-place changes such as adding, removing, or updating elements.

Immutability means a container’s contents can’t be changed after it’s created. The collection designed to be immutable in Python is the tuple. When you make a tuple, its sequence of elements is fixed: you can’t reassign an item, insert or remove elements, or sort it in place. If you want different contents, you create a new tuple, for example by concatenation or slicing. This immutability is why tuples are suitable as dictionary keys or as elements of sets—their value won’t change in a way that would affect hashing.

Keep in mind that if a tuple contains mutable objects (like a list), those inner objects can be changed, but the tuple itself won’t reconfigure which objects it references or how many there are. In contrast, lists, dictionaries, and sets are mutable; they allow in-place changes such as adding, removing, or updating elements.