Python: what is the difference between (1,2,3) and [1,2,3], and when should I use each?

Question

In many places, (1,2,3) (a tuple) and [1,2,3] (a list) can be used interchangeably.

When should I use one or the other, and why?

Answer 1

The list [1,2,3] is dynamic and flexible but that flexibility comes at a speed cost.

The tuple (1,2,3) is fixed (immutable) and therefore faster.