What is the difference between a list and a tuple in Python?

What is the difference between a list and a tuple in Python?

• A. A list is immutable and uses less memory; a tuple is mutable.
• B. A list is mutable with more methods; a tuple is immutable and uses less memory.
• C. A list cannot be iterated; a tuple can.
• D. There is no difference; they are interchangeable.

Answer: (C)

Lists and tuples differ mainly in mutability. A list is mutable, so you can change its contents after creation—append items, remove them, or assign to specific positions. A tuple, on the other hand, is immutable; once created, its items can’t be changed. This immutability makes tuples safer to use as fixed collections and allows them to be used as dictionary keys if all their elements are hashable. Because lists are mutable, they come with a larger set of methods for modifying data (such as append, extend, insert, remove, and pop). Tuples have far fewer methods (for example, count and index) since you can’t alter the sequence after it’s created. Another practical difference is memory and performance: tuples typically use less memory and can be slightly faster to iterate, while lists carry more overhead due to their mutability and broader method set. Remember that both structures are iterable, so the idea that a list cannot be iterated is not correct. You can loop over either type just fine. If you need a fixed, unchangeable collection that can serve as a dictionary key, a tuple is the appropriate choice. If you need to modify the collection or rely on a rich set of methods to change its contents, a list is the way to go.

Lists and tuples differ mainly in mutability. A list is mutable, so you can change its contents after creation—append items, remove them, or assign to specific positions. A tuple, on the other hand, is immutable; once created, its items can’t be changed. This immutability makes tuples safer to use as fixed collections and allows them to be used as dictionary keys if all their elements are hashable.

Because lists are mutable, they come with a larger set of methods for modifying data (such as append, extend, insert, remove, and pop). Tuples have far fewer methods (for example, count and index) since you can’t alter the sequence after it’s created.

Another practical difference is memory and performance: tuples typically use less memory and can be slightly faster to iterate, while lists carry more overhead due to their mutability and broader method set.

Remember that both structures are iterable, so the idea that a list cannot be iterated is not correct. You can loop over either type just fine. If you need a fixed, unchangeable collection that can serve as a dictionary key, a tuple is the appropriate choice. If you need to modify the collection or rely on a rich set of methods to change its contents, a list is the way to go.